WorldWideScience

Sample records for infrared solar observations

  1. An Airborne Infrared Spectrometer for Solar Eclipse Observations

    Science.gov (United States)

    Samra, Jenna; DeLuca, Edward E.; Golub, Leon; Cheimets, Peter; Philip, Judge

    2016-05-01

    The airborne infrared spectrometer (AIR-Spec) is an innovative solar spectrometer that will observe the 2017 solar eclipse from the NSF/NCAR High-Performance Instrumented Airborne Platform for Environmental Research (HIAPER). AIR-Spec will image five infrared coronal emission lines to determine whether they may be useful probes of coronal magnetism.The solar magnetic field provides the free energy that controls coronal heating, structure, and dynamics. Energy stored in coronal magnetic fields is released in flares and coronal mass ejections and ultimately drives space weather. Therefore, direct coronal field measurements have significant potential to enhance understanding of coronal dynamics and improve solar forecasting models. Of particular interest are observations of field lines in the transitional region between closed and open flux systems, providing important information on the origin of the slow solar wind.While current instruments routinely observe only the photospheric and chromospheric magnetic fields, AIR-Spec will take a step toward the direct observation of coronal fields by measuring plasma emission in the infrared at high spatial and spectral resolution. During the total solar eclipse of 2017, AIR-Spec will observe five magnetically sensitive coronal emission lines between 1.4 and 4 µm from the HIAPER Gulfstream V at an altitude above 14.9 km. The instrument will measure emission line intensity, width, and Doppler shift, map the spatial distribution of infrared emitting plasma, and search for waves in the emission line velocities.AIR-Spec consists of an optical system (feed telescope, grating spectrometer, and infrared detector) and an image stabilization system, which uses a fast steering mirror to correct the line-of-sight for platform perturbations. To ensure that the instrument meets its research goals, both systems are undergoing extensive performance modeling and testing. These results are shown with reference to the science requirements.

  2. The solar-flare infrared continuum: observational techniques and upper limits

    International Nuclear Information System (INIS)

    Hudson, H.S.

    1975-01-01

    Exploratory observations at 20μ and 350 μ have determined detection thresholds for solar flares in these wavelengths. In the 20μ range solar atmospheric fluctuations (the 'temperature field') set the basic limits on flare detectability at approximately 5K; at 350μ the extinction in the Earth's atmosphere provides the basic limitation of approximately 30 K. These thresholds are low enough for the successful detection of several infrared-emitting components of large flares. Limited observing time and lack of solar activity have prevented observations of large flares up to the present, but the techniques promise to be extremely useful in the future. The upper limits obtained thus far, for subflares, indicate that the thickness of the Hα flare region does not exceed approximately 10 km. This result confirms the conclusion of Suemoto and Hiei (1959) regarding the small effective thickness of the Hα-emitting regions in solar flares. (Auth.)

  3. Solar-Iss a New Solar Reference Spectrum Covering the Far UV to the Infrared (165 to 3088 Nm) Based on Reanalyzed Solar/solspec Cycle 24 Observations

    Science.gov (United States)

    Damé, L.; Meftah, M.; Irbah, A.; Hauchecorne, A.; Bekki, S.; Bolsée, D.; Pereira, N.; Sluse, D.; Cessateur, G.

    2017-12-01

    Since April 5, 2008 and until February 15, 2017, the SOLSPEC (SOLar SPECtrometer) spectro-radiometer of the SOLAR facility on the International Space Station performed accurate measurements of Solar Spectral Irradiance (SSI) from the far ultraviolet to the infrared (165 nm to 3088 nm). These measurements, unique by their large spectral coverage and long time range, are of primary importance for a better understanding of solar physics and of the impact of solar variability on climate (via Earth's atmospheric photochemistry), noticeably through the "top-down" mechanism amplifying ultraviolet (UV) solar forcing effects on the climate (UV affects stratospheric dynamics and temperatures, altering interplanetary waves and weather patterns both poleward and downward to the lower stratosphere and troposphere regions). SOLAR/SOLSPEC, with almost 9 years of observations covering the essential of the unusual solar cycle 24 from minimum in 2008 to maximum, allowed to establish new reference solar spectra from UV to IR (165 to 3088 nm) at minimum (beginning of mission) and maximum of activity. The complete reanalysis was possible thanks to revised engineering corrections, improved calibrations and advanced procedures to account for thermal, aging and pointing corrections. The high quality and sensitivity of SOLSPEC data allow to follow temporal variability in UV but also in visible along the cycle. Uncertainties on these measurements are evaluated and results, absolute reference spectra and variability, are compared with other measurements (WHI, ATLAS-3, SCIAMACHY, SORCE/SOLSTICE, SORCE/SIM) and models (SATIRE-S, NRLSSI, NESSY)

  4. Use of COTS uncooled microbolometers for the observation of solar eruptions in far infrared

    Science.gov (United States)

    Le Ruyet, B.; Bernardi, P.; Sémery, A.

    2017-11-01

    The Small Explorer for Solar Eruptions (SMESE) mission is a French-Chinese satellite dedicated to the combined study of coronal mass ejections and flares. It should operate by the beginning of 2013. The spacecraft is based on a generic MYRIADE platform developed by CNES. Its payload consists of a Lyman α imager and a Lyman α chronograph (LYOT), a far infrared telescope (DESIR) and a hard X and γ ray spectrometer (HEBS). Its Sun-synchronous orbit will allow for continuous observations. LESIA (Laboratoire d'Etudes Spatiales et d'Instrumentation en Astrophysique, in Paris-Meudon Observatory) is in charge of DESIR instrument. DESIR (Detection of Eruptive Solar InfraRed emission) is an imaging photometer observing the sun in two bandwidths: [25; 45μm] and [80; 130μm]. The detector is a commercially available, uncooled microbolometer focal plane array (UL 02 05 1, from ULIS) designed for thermographic imaging in the 8-14 μm wavelength range. The 160x120 pixels are based on amorphous silicon, with dimensions 35x35 μm2. The performances in terms of noise and dynamics given by the manufacturer associated with simulations of a perfect quarter-wave cavity to predict the microbolometer absorption, make possible the use of such a detector to fulfil the DESIR detection specifications in the two FIR bandwidths. During the A Phase, tests have been carried out in our laboratory to validate the feasibility of the project. In this work, we present the first results obtained on the microbolometer performances in the FIR domain.

  5. Solar and infrared radiation measurements

    CERN Document Server

    Vignola, Frank; Michalsky, Joseph

    2012-01-01

    The rather specialized field of solar and infrared radiation measurement has become more and more important in the face of growing demands by the renewable energy and climate change research communities for data that are more accurate and have increased temporal and spatial resolution. Updating decades of acquired knowledge in the field, Solar and Infrared Radiation Measurements details the strengths and weaknesses of instruments used to conduct such solar and infrared radiation measurements. Topics covered include: Radiometer design and performance Equipment calibration, installation, operati

  6. Comparison of the Changes in the Visible and Infrared Irradiance Observed by the SunPhotometers on EURECA to the UARS Total Solar and UV Irradiances

    Science.gov (United States)

    Pap, Judit

    1995-01-01

    Solar irradiance in the near-UV (335 nm), visible (500 nm) and infrared (778 nm) spectral bands has been measured by the SunPhotometers developed at the World Radiation Center, Davos, Switzerland on board the European Retrievable Carrier between August 1992 and May 1993. Study of the variations in the visible and infrared irradiance is important for both solar and atmospheric physics. The purpose of this paper is to examine the temporal variations observed in the visible and infrared spectral bands after eliminating the trend in the data mainly related to instrument degradation. The effect of active regions in these spectral irradiances is clearly resolved. Variations in the visible and infrared irradiances are compared to total solar irradiance observed by the SOVA2 radiometer on the EURECA platform and by the ACRIMII radiometer on UARS as well as to UV observations of the UARS and NOAA9 satellites. The space-borne spectral irradiance observations are compared to the photometric sunspot deficit and CaII K irradiance measured at the San Fernando Observatory, California State University at Northridge in order to study the effect of active regions in detail.

  7. Infrared solar physics from the South Pole

    Science.gov (United States)

    Deming, Drake

    1989-01-01

    Infrared (IR) observations of the sun could greatly benefit from the quality of the South Pole as an IR site, and the potential for multi-day sequences of uninterrupted observations. A nearly continuous picture of the evolution of the magnetic field in solar active regions could be obtained using vector magnetographs, especially vector magnetographs which incorporate IR array detectors. Observations of the sun over a range of wavelengths in the IR continuum could also be used to study the vertical propagation characteristics of the solar p-mode oscillations.

  8. Far infrared supplement: Catalog of infrared observations, second edition

    International Nuclear Information System (INIS)

    Gezari, D.Y.; Schmitz, M.; Mead, J.M.

    1988-08-01

    The Far Infrared Supplement: Catalog of Infrared Observations summarizes all infrared astronomical observations at far infrared wavelengths (5 to 1000 microns) published in the scientific literature from 1965 through 1986. The Supplement list contain 25 percent of the observations in the full Catalog of Infrared Observations (CIO), and essentially eliminates most visible stars from the listings. The Supplement is thus more compact than the main catalog, and is intended for easy reference during astronomical observations. The Far Infrared Supplement (2nd Edition) includes the Index of Infrared Source Positions and the Bibliography of Infrared Astronomy for the subset of far infrared observations listed

  9. Infrared observation of the early universe

    International Nuclear Information System (INIS)

    Matsumoto, T.

    1984-01-01

    The rocket observation of the near-infrared extragalactic background radiation and its influence on the cosmology are described. The furute plans to observe the near-infrared and far-infrared backgrounds are also presented. (author)

  10. Infrared observations of planetary atmospheres

    International Nuclear Information System (INIS)

    Orton, G.S.; Baines, K.H.; Bergstralh, J.T.

    1988-01-01

    The goal of this research in to obtain infrared data on planetary atmospheres which provide information on several aspects of structure and composition. Observations include direct mission real-time support as well as baseline monitoring preceding mission encounters. Besides providing a broader information context for spacecraft experiment data analysis, observations will provide the quantitative data base required for designing optimum remote sensing sequences and evaluating competing science priorities. In the past year, thermal images of Jupiter and Saturn were made near their oppositions in order to monitor long-term changes in their atmospheres. Infrared images of the Jovian polar stratospheric hot spots were made with IUE observations of auroral emissions. An exploratory 5-micrometer spectrum of Uranus was reduced and accepted for publication. An analysis of time-variability of temperature and cloud properties of the Jovian atomsphere was made. Development of geometric reduction programs for imaging data was initiated for the sun workstation. Near-infrared imaging observations of Jupiter were reduced and a preliminary analysis of cloud properties made. The first images of the full disk of Jupiter with a near-infrared array camera were acquired. Narrow-band (10/cm) images of Jupiter and Saturn were obtained with acousto-optical filters

  11. Infrared observations of AE Aquarii

    Science.gov (United States)

    Tanzi, E. G.; Chincarini, G.; Tarenghi, M.

    1981-01-01

    Broadband infrared observations of the cataclysmic variable AE Aquarii are reported. The observations were obtained in the J, H, K and L filters with the InSb photometer attached to the 1-m telescope of the European Southern Observatory. The infrared energy distribution observed from 0.35 to 3.5 microns for phase 0.5 suggests a spectral type of K5 V for the secondary and a distance to the system of approximately 70 pc if an absolute magnitude of 7.3 is assumed. Monitoring of the flux at 2.2 microns reveals a variability with an amplitude of approximately 0.3 magnitude over one third of the orbital period, the nature of which is under investigation.

  12. Infrared spectral observation of stars

    International Nuclear Information System (INIS)

    Komaki, Kazuo; Kodaira, Keiichi; Tanaka, W.; Suemoto, Zenzaburo

    1976-01-01

    The atmosphere of fixed stars must be studied in a supplementary way with both observation and theory. In case of low-temperature stars, however, there are difficulties in both two aspects. Under the situation, the multi-color measurement of the near infrared region was performed with a balloon telescope BAT-1 (the aperture of 15 cm) on June 17 and 18, 1975. For the red supergiant αSco, the data of light measurement was able to be obtained. (mori, K.)

  13. Infrared Observations of FS CMa Stars

    Science.gov (United States)

    Sitko, Michael L.; Russell, R. W.; Lynch, D. K.; Grady, C. A.; Hammel, H. B.; Beerman, L. C.; Day, A. N.; Huelsman, D.; Rudy, R. J.; Brafford, S. M.; Halbedel, E. M.

    2009-01-01

    A subset of non-supergiant B[e] stars has recently been recognized as forming a fairly unique class of objects with very strong emission lines, infrared excesses, and locations not associated with star formation. The exact evolutionary state of these stars, named for the prototype FS CMa, is uncertain, and they have often been classified as isolated Herbig AeBe stars. We present infrared observations of two of these stars, HD 45677 (FS CMa), HD 50138 (MWC 158), and the candidate FS CMa star HD 190073 (V1295 Aql) that span over a decade in time. All three exhibit an emission band at 10 microns due to amorphous silicates, confirming that much (if not all) of the infrared excess is due to dust. HD 50138 is found to exhibit 20% variability between 3-13 microns that resembles that found in pre-main sequence systems (HD 163296 and HD 31648). HD 45677, despite large changes at visual wavelengths, has remained relatively stable in the infrared. To date, no significant changes have been observed in HD 190073. This work is supported in part by NASA Origins of Solar Systems grant NAG5-9475, NASA Astrophysics Data Program contract NNH05CD30C, and the Independent Research and Development program at The Aerospace Corporation.

  14. Solar Observations at Submillimeter Wavelengths

    Science.gov (United States)

    Kaufmann, P.

    We review earlier to recent observational evidences and theoretical motivations leading to a renewed interest to observe flares in the submillimeter (submm) - infrared (IR) range of wavelengths. We describe the new solar dedicated submillimeter wave telescope which began operations at El Leoncito in the Argentina Andes: the SST project. It consists of focal plane arrays of two 405 GHz and four 212 GHz radiometers placed in a 1.5-m radome-enclosed Cassegrain antenna, operating simultaneously with one millisecond time resolution. The first solar events analyzed exhibited the onset of rapid submm-wave spikes (100-300 ms), well associated to other flare manifestations, especially at X-rays. The spikes positions were found scattered over the flaring source by tens of arcseconds. For one event an excellent association was found between the gamma-ray emission time profile and the rate of occurrence of submm-wave rapid spikes. The preliminary results favour the idea that bulk burst emissions are a response to numerous fast energetic injections, discrete in time, produced at different spatial positions over the flaring region. Coronal mass ejections were associated to the events studied. Their trajectories extrapolated to the solar surface appear to correspond to the onset time of the submm-wave spikes, which might represent an early signature of the CME's initial acceleration process.

  15. High resolution solar observations

    International Nuclear Information System (INIS)

    Title, A.

    1985-01-01

    Currently there is a world-wide effort to develop optical technology required for large diffraction limited telescopes that must operate with high optical fluxes. These developments can be used to significantly improve high resolution solar telescopes both on the ground and in space. When looking at the problem of high resolution observations it is essential to keep in mind that a diffraction limited telescope is an interferometer. Even a 30 cm aperture telescope, which is small for high resolution observations, is a big interferometer. Meter class and above diffraction limited telescopes can be expected to be very unforgiving of inattention to details. Unfortunately, even when an earth based telescope has perfect optics there are still problems with the quality of its optical path. The optical path includes not only the interior of the telescope, but also the immediate interface between the telescope and the atmosphere, and finally the atmosphere itself

  16. Longwave infrared observation of urban landscapes

    Science.gov (United States)

    Goward, S. N.

    1981-01-01

    An investigation is conducted regarding the feasibility to develop improved methods for the identification and analysis of urban landscapes on the basis of a utilization of longwave infrared observations. Attention is given to landscape thermal behavior, urban thermal properties, modeled thermal behavior of pavements and buildings, and observed urban landscape thermal emissions. The differential thermal behavior of buildings, pavements, and natural areas within urban landscapes is found to suggest that integrated multispectral solar radiant reflectance and terrestrial radiant emissions data will significantly increase potentials for analyzing urban landscapes. In particular, daytime satellite observations of the considered type should permit better identification of urban areas and an analysis of the density of buildings and pavements within urban areas. This capability should enhance the utility of satellite remote sensor data in urban applications.

  17. Frontier of solar observation. Solar activity observed by 'HINODE' mission

    International Nuclear Information System (INIS)

    Watanabe, Tetsuya

    2008-01-01

    After launched in September 2006, solar observation satellite 'HINODE' has been a solar observatory on orbit with the scientific instruments well operated and its continuous observation was conducted steadily on almost all solar atmospheres from photosphere to corona. 'HINODE' was equipped with the solar optical telescope, extreme-ultraviolet imaging spectrometer and x-ray telescope and aimed at clarifying the mystery of solar physics related with coronal heating and magnetic reconnection. Present state of 'HINODE' was described from observations made in initial observation results, which have made several discoveries, such as Alfven waves in the corona, unexpected dynamics in the chromosphere and photosphere, continuous outflowing plasma as a possible source of solar wind, and fine structures of magnetic field in sunspots and solar surface. (T. Tanaka)

  18. Infrared observations of Seyfert galaxies and quasars

    International Nuclear Information System (INIS)

    Neugebauer, G.

    1978-01-01

    The infrared energy distributions of the Seyfert galaxies apparently contain three components: a galactic stellar component, a thermal component from heated dust, plus a nonthermal component. The appearance of the infrared energy distribution depends on which component dominates. There is also a correlation observed between the infrared energy distribution and the Khachikian Weedman class. Preliminary data on bright quasars are given. The infrared energy distributions generally increase into the infrared with a power law slope of approximately 1. In detail they differ from power laws with a significant fraction emitting most of their energy near 3μm. No differences in radio loud and radio quiet are obvious from the infrared energy distributions. The variability of the quasars in the infrared is generally correlated with the variability in the visible, although significant exceptions have been observed. (Auth.)

  19. Infrared observations of extragalactic sources

    International Nuclear Information System (INIS)

    Kleinmann, D.E.

    1977-01-01

    The available balloon-borne and airborne infrared data on extragalactic sources, in particular M 82, NGC 1068 and NGC 253, is reviewed and discussed in the context of the extensive groundbased work. The data is examined for the clues they provide on the nature of the ultimate source of the energy radiated and on the mechanism(s) by which it is radiated. Since the discovery of unexpectedly powerful infrared radiation from extragalactic objects - a discovery now about 10 years old - the outstanding problems in this field have been to determine (1) the mechanism by which prodigious amounts of energy are released in the infrared, and (2) the nature of the underlying energy source. (Auth.)

  20. Infrared investigation of the temperature structure of the solar atmosphere

    International Nuclear Information System (INIS)

    Allen, R.G.

    1978-01-01

    Narrow-band continuum limb darkening observations of the sun were taken with the Infrared Spectrometer and the West Auxiliary of the McMath Solar Telescope during the first half of 1974. The infrared limb darkening measures were used with a few absolute intensity and limb darkening measures of other investigators to develop a series of empirical solar models. The temperatures in most of the solar models were adjusted until the predictions of the model atmosphere program matched the observational measures as well as possible. Limb darkening residuals were calculated by subtracting the observational measures of the limb darkening from the limb darkening measures that were computed from the program. Experiments with several models indicated that a steep temperature gradient was needed to fit the observations at short wavelengths while a rather low temperature gradient was needed at long wavelengths. Non-LTE effects and errors in the H - opacity were ruled out as possible sources of this discrepancy. An excellent fit to the observations was ultimately achieved with a two-component LTE solar model. The hot component of this model represents the half of the solar surface that is above the median temperature at each depth; while the cool component represents the half of the solar surface that is below the median temperature. Most of the observations are fitted to within the expected errors by this model. Discrepancies below 4500 A are probably due to line blanketing. The splitting between the hot and cool components of the model is consistent with current estimates of the rms intensity fluctuations in the solar atmosphere. The model also resembles several theoretical two-component models that have recently appeared in the literature

  1. Strong Solar Control of Infrared Aurora on Jupiter: Correlation Since the Last Solar Maximum

    Science.gov (United States)

    Kostiuk, T.; Livengood, T. A.; Hewagama, T.

    2009-01-01

    Polar aurorae in Jupiter's atmosphere radiate throughout the electromagnetic spectrum from X ray through mid-infrared (mid-IR, 5 - 20 micron wavelength). Voyager IRIS data and ground-based spectroscopic measurements of Jupiter's northern mid-IR aurora, acquired since 1982, reveal a correlation between auroral brightness and solar activity that has not been observed in Jovian aurora at other wavelengths. Over nearly three solar cycles, Jupiter auroral ethane emission brightness and solar 10.7 cm radio flux and sunspot number are positively correlated with high confidence. Ethane line emission intensity varies over tenfold between low and high solar activity periods. Detailed measurements have been made using the GSFC HIPWAC spectrometer at the NASA IRTF since the last solar maximum, following the mid-IR emission through the declining phase toward solar minimum. An even more convincing correlation with solar activity is evident in these data. Current analyses of these results will be described, including planned measurements on polar ethane line emission scheduled through the rise of the next solar maximum beginning in 2009, with a steep gradient to a maximum in 2012. This work is relevant to the Juno mission and to the development of the Europa Jupiter System Mission. Results of observations at the Infrared Telescope Facility (IRTF) operated by the University of Hawaii under Cooperative Agreement no. NCC5-538 with the National Aeronautics and Space Administration, Science Mission Directorate, Planetary Astronomy Program. This work was supported by the NASA Planetary Astronomy Program.

  2. Infrared detectors for Earth observation

    Science.gov (United States)

    Barnes, K.; Davis, R. P.; Knowles, P.; Shorrocks, N.

    2016-05-01

    IASI (Infrared Atmospheric Sounding Interferometer), developed by CNES and launched since 2006 on the Metop satellites, is established as a major source of data for atmospheric science and weather prediction. The next generation - IASI NG - is a French national contribution to the Eumetsat Polar System Second Generation on board of the Metop second generation satellites and is under development by Airbus Defence and Space for CNES. The mission aim is to achieve twice the performance of the original IASI instrument in terms of sensitivity and spectral resolution. In turn, this places very demanding requirements on the infrared detectors for the new instrument. Selex ES in Southampton has been selected for the development of the infrared detector set for the IASI-NG instruments. The wide spectral range, 3.6 to 15.5 microns, is covered in four bands, each served by a dedicated detector design, with a common 4 x 4 array format of 1.3 mm square macropixels. Three of the bands up to 8.7 microns employ photovoltaic MCT (mercury cadmium telluride) technology and the very long wave band employs photoconductive MCT, in common with the approach taken between Airbus and Selex ES for the SEVIRI instrument on Second Generation Meteosat. For the photovoltaic detectors, the MCT crystal growth of heterojunction photodiodes is by the MOVPE technique (metal organic vapour phase epitaxy). Novel approaches have been taken to hardening the photovoltaic macropixels against localised crystal defects, and integrating transimpedance amplifiers for each macropixel into a full-custom silicon read out chip, which incorporates radiation hard design.

  3. Observation of infrared absorption of InAs quantum dot structures in AlGaAs matrix toward high-efficiency solar cells

    Science.gov (United States)

    Yoshikawa, Hirofumi; Watanabe, Katsuyuki; Kotani, Teruhisa; Izumi, Makoto; Iwamoto, Satoshi; Arakawa, Yasuhiko

    2018-06-01

    In accordance with the detailed balance limit model of single-intermediate-band solar cells (IBSCs), the optimum matrix bandgap and IB–conduction band (CB) energy gap are ∼1.9 and 0.7 eV, respectively. We present the room-temperature polarized infrared absorption of 20 stacked InAs quantum dot (QD) structures in the Al0.32Ga0.68As matrix with a bandgap of ∼1.9 eV for the design of high-efficiency IBSCs by using a multipass waveguide geometry. We find that the IB–CB absorption is almost independent of the light polarization, and estimate the magnitude of the absorption per QD layer to be ∼0.01%. We also find that the IB–CB absorption edge of QD structures with a wide-gap matrix is ∼0.41 eV. These results indicate that both the significant increase in the magnitude of IB–CB absorption and the lower energy of the IB state for the higher IB–CB energy gap are necessary toward the realization of high-efficiency IBSCs.

  4. Observation of galactic far-infrared ray

    International Nuclear Information System (INIS)

    Maihara, Toshinori; Oda, Naoki; Okuda, Haruyuki; Sugiyama, Takuya; Sakai, Kiyomi.

    1978-01-01

    Galactic far-infrared was observed to study the spatial distribution of interstellar dust. Far-infrared is emitted by interstellar dust distributing throughout the galactic plane. The observation of far-infrared is very important to study the overall structure of the galaxy, that is the structure of the galactic arm and gas distribution. The balloon experiment was conducted on May 25, 1978. The detector was a germanium bolometer cooled by liquid helium. The size of the detector is 1.6 mm in diameter. The geometrical factor was 4 x 10 3 cm 2 sr. The result showed that the longitude distribution of far-infrared at 150 μm correlated with H 166 α recombination line. This indicates that the observed far-infrared is emitted by interstellar dust heated by photons of Lyman continuum. (Yoshimori, M.)

  5. Infrared Images of an Infant Solar System

    Science.gov (United States)

    2002-05-01

    understanding of the formation of solar-type stars and planetary systems from the interstellar medium. However, in most cases the large difference of brightness between the young star and its surrounding material makes it impossible to image directly the circumstellar disk. But when the disk is seen nearly edge-on, the light from the central star will be blocked out by the dust grains in the disk. Other grains below and above the disk midplane scatter the stellar light, producing a typical pattern of a dark lane between two reflection nebulae. The first young stellar object (YSO) found to display this typical pattern, HH 30 IRS in the Taurus dark cloud at a distance of about 500 light-years (140 pc), was imaged by the Hubble Space telescope (HST) in 1996. Edge-on disks have since also been observed with ground-based telescopes in the near-infrared region of the spectrum, sometimes by means of adaptive optics techniques or speckle imaging, or under very good sky image quality, cf. ESO PR Photo 03d/01 with a VLT image of such an object in the Orion Nebula. A surprise discovery ESO PR Photo 12a/02 ESO PR Photo 12a/02 [Preview - JPEG: 400 x 459 pix - 55k] [Normal - JPEG: 800 x 918 pix - 352k] Caption : PR Photo 12a/02 shows a three-colour reproduction of the discovery image of strange-looking object (nicknamed the "Flying Saucer" by the astronomers), obtained with the SOFI multi-mode instrument at the ESO 3.5-m New Technology Telescope (NTT) at the La Silla Observatory. Compared to the unresolved stars in the field, the image of this object appears extended. Two characteristic reflection nebulae are barely visible, together with a marginally resolved dark dust lane in front of the star and oriented East-West. Technical information about the photo is available below. Last year, a group of astronomers [1] carried out follow-up observations of new X-ray sources found by the ESA XMM-Newton and NASA Chandra X-ray satellites. They were looking at the periphery of the so-called Rho

  6. SOLAR-ISS: A new reference spectrum based on SOLAR/SOLSPEC observations

    Science.gov (United States)

    Meftah, M.; Damé, L.; Bolsée, D.; Hauchecorne, A.; Pereira, N.; Sluse, D.; Cessateur, G.; Irbah, A.; Bureau, J.; Weber, M.; Bramstedt, K.; Hilbig, T.; Thiéblemont, R.; Marchand, M.; Lefèvre, F.; Sarkissian, A.; Bekki, S.

    2018-03-01

    Context. Since April 5, 2008 and up to February 15, 2017, the SOLar SPECtrometer (SOLSPEC) instrument of the SOLAR payload on board the International Space Station (ISS) has performed accurate measurements of solar spectral irradiance (SSI) from the middle ultraviolet to the infrared (165 to 3088 nm). These measurements are of primary importance for a better understanding of solar physics and the impact of solar variability on climate. In particular, a new reference solar spectrum (SOLAR-ISS) is established in April 2008 during the solar minima of cycles 23-24 thanks to revised engineering corrections, improved calibrations, and advanced procedures to account for thermal and aging corrections of the SOLAR/SOLSPEC instrument. Aims: The main objective of this article is to present a new high-resolution solar spectrum with a mean absolute uncertainty of 1.26% at 1σ from 165 to 3000 nm. This solar spectrum is based on solar observations of the SOLAR/SOLSPEC space-based instrument. Methods: The SOLAR/SOLSPEC instrument consists of three separate double monochromators that use concave holographic gratings to cover the middle ultraviolet (UV), visible (VIS), and infrared (IR) domains. Our best ultraviolet, visible, and infrared spectra are merged into a single absolute solar spectrum covering the 165-3000 nm domain. The resulting solar spectrum has a spectral resolution varying between 0.6 and 9.5 nm in the 165-3000 nm wavelength range. We build a new solar reference spectrum (SOLAR-ISS) by constraining existing high-resolution spectra to SOLAR/SOLSPEC observed spectrum. For that purpose, we account for the difference of resolution between the two spectra using the SOLAR/SOLSPEC instrumental slit functions. Results: Using SOLAR/SOLSPEC data, a new solar spectrum covering the 165-3000 nm wavelength range is built and is representative of the 2008 solar minimum. It has a resolution better than 0.1 nm below 1000 nm and 1 nm in the 1000-3000 nm wavelength range. The new

  7. Infrared Observations of Cometary Dust and Nuclei

    Science.gov (United States)

    Lisse, Carey

    2004-01-01

    This bibliography lists citations for publications published under the grant. Subjects of the publications include cometary dust, instellar and interplanetary dust, comet nuclei and comae, Comet Hale-Bopp, infrared observations of comets, mass loss, and comet break-up.

  8. Filling-in of Near-infrared Solar Lines by Terrestrial Fluorescence and Other Geophysical Effects: Simulations and Space-based Observations from SCIAMACHY and GOSAT

    Science.gov (United States)

    Joiner, Joanna (Editor); Yoshida, Yasuko; Vasilkov, A. P.; Middleton, E. M. (Editor); Campbell, P. K. E.; Yoshida, Y.; Huze, A.; Corp, L. A.

    2012-01-01

    Global mapping of terrestrial vegetation fluorescence from space has recently been accomplished with high spectral resolution (nu/nu greater than 35 000) measurements from the Japanese Greenhouse gases Observing SAellite (GOSAT). These data are of interest because they can potentially provide global information on the functional status of vegetation including light-use efficiency and global primary productivity that can be used for global carbon cycle modeling. Quantifying the impact of fluorescence on the O2-A band is important as this band is used for photon pathlength characterization in cloud- and aerosol-contaminated pixels for trace-gas retrievals including CO2. Here, we examine whether fluorescence information can be derived from space using potentially lower-cost hyperspectral instrumentation, i.e., more than an order of magnitude less spectral resolution (nu/nu approximately 1600) than GOSAT, with a relatively simple algorithm. We discuss laboratory measurements of fluorescence near one of the few wide and deep solar Fraunhofer lines in the long-wave tail of the fluorescence emission region, the calcium (Ca) II line at 866 nm that is observable with a spectral resolution of approximately 0.5 nm. The filling-in of the Ca II line due to additive signals from various atmospheric and terrestrial effects, including fluorescence, is simulated. We then examine filling-in of this line using the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) satellite instrument. In order to interpret the satellite measurements, we developed a general approach to correct for various instrumental artifacts that produce false filling-in of solar lines in satellite measurements. The approach is applied to SCIAMACHY at the 866 nm Ca II line and to GOSAT at 758 and 770 nm on the shoulders of the O2-A feature where there are several strong solar Fraunhofer lines that are filled in primarily by vegetation fluorescence. Finally, we compare temporal and

  9. Solar polarimetry: observations and theories

    Energy Technology Data Exchange (ETDEWEB)

    Rees, D E [Sydney Univ. (Australia). Dept. of Applied Mathematics

    1982-01-01

    This review surveys some recent observations of polarization in solar spectral lines with emphasis on their theoretical interpretation. Observations of non-magnetic resonance line polarization offer a new approach to temperature and density modelling of the atmosphere. They also provide a basis for comparison in Hanle effect studies of weak magnetic fields on the solar disk. Measurements of the Hanle effect are being used to deduce vector magnetic fields in prominences. It is now feasible to try to infer the vector field distribution in an active region such as a sunspot from analysis of the stokes parameter profiles of a Zeeman split line.

  10. Solar System Observations with the James Webb Space Telescope

    OpenAIRE

    Norwood, James; Hammel, Heidi; Milam, Stefanie; Stansberry, John; Lunine, Jonathan; Chanover, Nancy; Hines, Dean; Sonneborn, George; Tiscareno, Matthew; Brown, Michael; Ferruit, Pierre

    2014-01-01

    The James Webb Space Telescope will enable a wealth of new scientific investigations in the near- and mid-infrared, with sensitivity and spatial/spectral resolution greatly surpassing its predecessors. In this paper, we focus upon Solar System science facilitated by JWST, discussing the most current information available concerning JWST instrument properties and observing techniques relevant to planetary science. We also present numerous example observing scenarios for a wide variety of Solar...

  11. Far infrared observations of the galactic center

    International Nuclear Information System (INIS)

    Gatley, I.

    1977-01-01

    Maps of a region 10' in diameter around the galactic center made simultaneously in three wavelength bands at 30 μm, 50 μm, and 100 μm with approximately 1' resolution are presented, and the distribution of far infrared luminosity and color temperature across this region is derived. The position of highest far infrared surface brightness coincides with the peak of the late-type stellar distribution and with the H II region Sgr A West. The high spatial and temperature resolution of the data is used to identify features of the far infrared maps with known sources of near infrared, radio continuum, and molecular emission. The emission mechanism and energy sources for the far infrared radiation are anslyzed qualitatively, and it is concluded that all of the observed far infrared radiation from the galactic center region can be attributed to thermal emission from dust heated both by the late-type stars and by the ultraviolet sources which ionize the H II regions. A self-consistent model for the far infrared emission from the galactic center region is presented. It is found that the visual extinction across the central 10 pc of the galaxy is only about 3 magnitudes, and that the dust density is fairly uniform in this region. An upper limit of 10 7 L/sub mass/ is set on the luminosity of any presently unidentified source of 0.1 to 1 μm radiation at the galactic center. Additional maps in the vicinity of the source Sgr B2 and observations of Sgr C bring the total number of H II regions within 1 0 of the galactic center studied by the present experiment to nine. The far infrared luminosity, color temperature and optical depth of these regions and the ratio of infrared flux to radio continuum flux lie in the range characteristic of spiral arm H II regions. The far infrared results are therefore consistent with the data that the galactic center H II regions are ionized by luminous, early type stars

  12. Jupiter's Mid-Infrared Aurora: Solar Connection and Minor Constituents

    Science.gov (United States)

    Kostiuk, Theodore; Livengood, T.A.; Fast, K.E.; Hewagama, T.; Schmilling, F.; Sonnabend, G.; Delgado, J.

    2009-01-01

    High spectral resolution in the 12 pin region of the polar regions of Jupiter reveal unique information on auroral phenomena and upper stratospheric composition. Polar aurorae in Jupiter's atmosphere radiate; throughout the electromagnetic spectrum from X-ray through mid-infrared (mid-IR, 5 - 20 micron wavelength). Voyager IRIS data and ground-based. spectroscopic measurements of Jupiter's northern mid-IR aurora acquired since 1982, reveal a correlation between auroral brightness and solar activity that has not been observed in Jovian aurora at other wavelengths. Over nearly three solar cycles, Jupiter auroral ethane, emission brightness and solar 10.7-cm radar flux and sunspot number are positively correlated with high confidence. Ethane line emission intensity varies over tenfold between low and high scalar activity periods. Detailed measurements have been made using the GSFC HIPWAC spectrometer at the NASA IRTF since the last solar maximum, following the mid-IR emission through the declining phase toward solar minimum. An even more convincing correlation with solar activity is evident in these data. The spectra measured contain features that cannot be attributed to ethane and are most likely spectra of minor constituents whose molecular bands overlap the v9 band of ethane. Possible candidates are allene, propane, and other higher order hydrocarbons. These features appear to be enhanced in the active polar regions. Laboratory measurements at comparable spectral resolution of spectra of candidate molecules will be used to identify the constituents. Current analyses of these results will be described, including planned measurements on polar ethane line emission scheduled through the rise of the next solar maximum beginning in 2009, with a steep gradient to a maximum in 2012. This work is relevant to the Juno mission and to the development of the NASA/ESA Europa Jupiter System Mission.

  13. Infrared observations of RS CVn stars

    Science.gov (United States)

    Berriman, G.; De Campli, W. M.; Werner, M. W.; Hatchett, S. P.

    1983-01-01

    The paper presents infrared photometry of the RS CVn binary stars AR Lac (1.2-10 microns) and MM Her (1.2-3.5 microns) as they egressed from their primary and secondary eclipses; of the eclipsing systems RS CVn and Z Her at maximum light (1.2-10 microns) and of the non-eclipsing systems UX Ari and HR 1099 (1.2-10 microns). An analysis of these and published V data based on flux ratio diagrams (linear analogues of color-color diagrams) shows that G and K stars supply the infrared light of these systems. In AR Lac, the combined light of a G5-K0 subgiant and either a late F dwarf or an early F subgiant can account for the observed visual and infrared light curves. None of these systems shows infrared emission from circumstellar matter. This result is simply understood: dust grains would not be expected to form in the physical conditions surrounding the subgiant, and the corona and chromosphere (whose properties have been deduced from spectroscopic X-ray observations) should not produce appreciable infrared emission.

  14. Solar radio observations and interpretations

    International Nuclear Information System (INIS)

    Rosenberg, H.

    1976-01-01

    The recent solar radio observations related to flares are reviewed for the frequency range of a few kilohertz to several gigahertz. The analysis of the radio data leads to boundary conditions on the acceleration processes which are responsible for the fast particles which cause radio emission. The role and cause of plasma turbulence at the plasma-frequency and at much lower frequencies is discussed in relation to the acceleration processes and the radio emission mechanisms for the various radio bursts. (author)

  15. Far-infrared observations of globules

    International Nuclear Information System (INIS)

    Keene, J.

    1981-01-01

    Observations of far-infrared emission from nine globules are presented. The intensity and uniformity of the emission confirm that the heat source is the interstellar radiation field. Spectra of B133 and B335 are presented; they are consistent with optically thin thermal emission from dust with temperature 13--16 K. The emissivity of the grains must fall as fast as lambda -2 for lambda>500 μm. The temperature and intensity of B335 are used to calculate the ratio of visual extinction to far-infrared emission frequency

  16. Diffuse infrared emission from the galaxy. I. Solar neighborhood

    International Nuclear Information System (INIS)

    Boulanger, F.; Perault, M.

    1988-01-01

    A large-scale study of the infrared emission originating in the solar neighborhood based on IRAS data is presented. Away from heating sources and outside molecular clouds, the infrared emission from the ISM is well-correlated with the column density of H I gas. The interstellar radiation field and the dust abundance are roughly uniform on scales of the order of 100 pc. The extinction in the polar caps is discussed, and the origin of the infrared emission from the solar neighborhood is investigated. It is shown that stars younger than a few 100 million yr are responsible for two-thirds of the infrared emission from the solar neighborhood, but that most of this emission comes from interstellar matter not associated with current star formation. The correlation between infrared and radio-continuum fluxes of galaxies breaks down on the scale of a few hundred pc around regions of star formation. 81 references

  17. Far-infrared spectrophotometer for astronomical observations

    Science.gov (United States)

    Moseley, H.; Silverberg, R. F.

    1981-01-01

    A liquid-helium-cooled far infrared spectrophotometer was built and used to make low resolution observations of the continua of several kinds of astronomical objects using the Kuiper Airborne Observatory. This instrument fills a gap in both sensitivity to continuum sources and spectral resolution between the broadband photometers with lambda/Delta lambda approximately 1 and spectrometers with lambda/Delta lambda greater than 50. While designed primarily to study planetary nebulae, the instrument permits study of the shape of the continua of many weak sources which cannot easily be observed with high resolution systems.

  18. Mobile solar mini power station filled with infrared heliochambers

    International Nuclear Information System (INIS)

    Abdukadirov, M.A.; Akhmedova, N.A.

    2000-01-01

    The work dedicated to development of perspective types of solar energetic devices of in-land application in accordance with conception about advantage of decentralized production of electrical and heat energy for supply of atom customers. It is given constructive particulars and characteristics of developed by authors mobile energy complex, which contents from block photoelectrical of convertor on the base of semiconductor solar elements, transparent in longwaved area out of edge of absorption base band, with power from 100 till 1000 Wt and heliochamber for accumulation of infrared part of solar radiation with wave length λ> 1 mcm. It is shown that, introduction into the system of energy complex the infrared heliochamber, increase the efficiency of equipment generally on the account of increasing the useful application of solar spectrum and extend her functional abilities. It is discussed the advantages of similar energy complex at decision of separate production tasks, including agriculture processing. (Author)

  19. Solar panel thermal cycling testing by solar simulation and infrared radiation methods

    Science.gov (United States)

    Nuss, H. E.

    1980-01-01

    For the solar panels of the European Space Agency (ESA) satellites OTS/MAROTS and ECS/MARECS the thermal cycling tests were performed by using solar simulation methods. The performance data of two different solar simulators used and the thermal test results are described. The solar simulation thermal cycling tests for the ECS/MARECS solar panels were carried out with the aid of a rotatable multipanel test rig by which simultaneous testing of three solar panels was possible. As an alternative thermal test method, the capability of an infrared radiation method was studied and infrared simulation tests for the ultralight panel and the INTELSAT 5 solar panels were performed. The setup and the characteristics of the infrared radiation unit using a quartz lamp array of approx. 15 sq and LN2-cooled shutter and the thermal test results are presented. The irradiation uniformity, the solar panel temperature distribution, temperature changing rates for both test methods are compared. Results indicate the infrared simulation is an effective solar panel thermal testing method.

  20. Solar System Observations with the James Webb Space Telescope

    Science.gov (United States)

    Norwood, James; Hammel, Heidi; Milam, Stefanie; Stansberry, John; Lunine, Jonathan; Chanover, Nancy; Hines, Dean; Sonneborn, George; Tiscareno, Matthew; Brown, Michael; hide

    2016-01-01

    The James Webb Space Telescope (JWST) will enable a wealth of new scientific investigations in the near- and mid-infrared, with sensitivity and spatial/spectral resolution greatly surpassing its predecessors. In this paper, we focus upon Solar System science facilitated by JWST, discussing the most current information available concerning JWST instrument properties and observing techniques relevant to planetary science. We also present numerous example observing scenarios for a wide variety of Solar System targets to illustrate the potential of JWST science to the Solar System community. This paper updates and supersedes the Solar System white paper published by the JWST Project in 2010. It is based both on that paper and on a workshop held at the annual meeting of the Division for Planetary Sciences in Reno, NV, in 2012.

  1. Solar cycle variability of nonmigrating tides in the infrared cooling of the thermosphere

    Science.gov (United States)

    Nischal, N.; Oberheide, J.; Mlynczak, M. G.; Marsh, D. R.

    2017-12-01

    Nitric Oxide (NO) at 5.3 μm and Carbon dioxide (CO2) at 15 μm are the major infrared emissions responsible for the radiative cooling of the thermosphere. We study the impact of two important diurnal nonmigrating tides, the DE2 and DE3, on NO and CO2 infrared emissions over a complete solar cycle (2002-2013) by (i) analyzing NO and CO2 cooling rate data from SABER and (ii) photochemical modeling using dynamical tides from a thermospheric empirical tidal model, CTMT. Both observed and modeled results show that the NO cooling rate amplitudes for DE2 and DE3 exhibit strong solar cycle dependence. NO 5.3 μm cooling rate tides are relatively unimportant for the infrared energy budget during solar minimum but important during solar maximum. On the other hand DE2 and DE3 in CO2 show comparatively small variability over a solar cycle. CO2 15 μm cooling rate tides remain, to a large extent, constant between solar minimum and maximum. This different responses by NO and CO2 emissions to the DE2 and DE3 during a solar cycle comes form the fact that the collisional reaction rate for NO is highly sensitive to the temperature comparative to that for CO2. Moreover, the solar cycle variability of these nonmigrating tides in thermospheric infrared emissions shows a clear QBO signals substantiating the impact of tropospheric weather system on the energy budget of the thermosphere. The relative contribution from the individual tidal drivers; temperature, density and advection to the observed DE2 and DE3 tides does not vary much over the course of the solar cycle, and this is true for both NO and CO2 emissions.

  2. Observational investigation of the solar oblateness

    International Nuclear Information System (INIS)

    Stebbins, R.T.

    1975-01-01

    The solar oblateness provides important information for solar physics and experimental relativity. After the solar neutrino flux, the sun's shape is the most revealing probe of the solar interior. Rapidly rotating interiors suggested to explain the solar neutrino paradox produce sizeable oblatenesses. Certain types of surface phenomena can also be investigated with precision diameter measurements. The relativistic advance of Mercury's perihelion has long been the principal experimental support for Einstein's theory of general relativity. Recent measurements of the solar oblateness have suggested that the relativistic advance is smaller than originally thought due to a contribution from a solar mass quadrupole moment. This interpretation of the perihelion advance would shift the experimental support to the scalar-tensor theory of gravitation. A debate over the interpretation of the oblateness measurements has resulted. In light of these circumstances, solar oblateness observations have been attempted. Improved experimental techniques have been devised, including a daytime astrometric telescope and an explicit definition of the sun's edge. Observations reveal a time varying excess equatorial brightness, that is, a variation in the limb darkening function between equator and pole, which would preclude accurate interpretation of previous solar oblateness measurements. This vindicates the alternate interpretations of other solar oblateness measurements. From these results, it can be concluded that the Mercury perihelion evidence firmly supports Einstein's General Theory of Relativity, the solar interiors cannot be rotating fast enough to account for the low solar neutrino flux, and a time varying excess equatorial brightness exists

  3. OSIRIS (Observing System Including PolaRisation in the Solar Infrared Spectrum) instrument: a multi-directional, polarized radiometer in the visible and shortwave infrared, airborne prototype of 3MI / EPS-SG Eumetsat - ESA mission

    Science.gov (United States)

    Matar, C.; Auriol, F.; Nicolas, J. M.; Parol, F.; Riedi, J.; Djellali, M. S.; Cornet, C.; Waquet, F.; Catalfamo, M.; Delegove, C.; Loisil, R.

    2017-12-01

    OSIRIS instrument largely inherits from the POLDER concept developed and operated between 1991 (first airborne prototype) and 2013 (end of the POLDER-3/PARASOL space-borne mission). It consists in two optical systems, one covering the visible to near infrared range (440, 490, 670, 763, 765, 870, 910 and 940 nm) and a second one for the shortwave infrared (940, 1020, 1240, 1360, 1620 and 2200 nm). Each optical system is composed of a wide field-of-view optics (114° and 105° respectively) associated to two rotating wheels with interferential filters (spectral) and analyzers filters (polarization) respectively, and a 2D array of detectors. For each channel, radiance is measured once without analyzer, followed by sequential measurements with the three analyzers shifted by an angle of 60° to reconstruct the total and polarized radiances. The complete acquisition sequence for all spectral channels last a couple of seconds according to the chosen measurement protocol. Thanks to the large field of view of the optics, any target is seen under several viewing angles during the aircraft motion. In a first step we will present the new ground characterization of the instrument based on laboratory measurements (linearity, flat-field, absolute calibration, induced polarization, polarizers efficiency and position), the radiometric model and the Radiometric Inverted Model (RIM) used to develop the Level 1 processing chain that is used to produce level 1 products (normalized radiances, polarized or not, with viewing geometries) from the instrument generated level 0 files (Digital Counts) and attitude information from inertial system. The stray light issues will be specifically discussed. In a second step we will present in-flight radiometric and geometric methods applied to OSIRIS data in order to control and validate ground-based calibrated products: molecular scattering method and sun-glint cross-band method for radiometric calibration, glories, rainbows and sun-glint targets

  4. A solar infrared photometer for space flight application

    Science.gov (United States)

    Kostiuk, Theodor; Deming, Drake

    1991-01-01

    A photometer concept which is capable of nearly simultaneous measurements of solar radiation from 1.6 to 200 microns in seven wavelength bands is described. This range of wavelengths can probe the solar photosphere from below the level of unit optical depth in the visible to the temperature minimum, about 500 km above it. An instrument package including a 20-cm Gregorian telescope and a filter wheel photometer utilizing noncryogenic pyroelectric infrared detectors is described. Approaches to the rejection of the visible solar spectrum in the instrument, the availability of optical and mechanical components, and the expected instrumental sensitivity are discussed. For wavelengths below 35 microns, the projected instrumental sensitivity is found to be adequate to detect the intensity signature of solar p-mode oscillations during 5 min of integration. For longer wavelengths, clear detection is expected through Fourier analysis of modest data sets.

  5. Gamma ray observations of the solar system

    International Nuclear Information System (INIS)

    1981-01-01

    Two general categories are discussed concerning the evolution of the solar system: the dualistic view, the planetesimal approach and the monistic view, the nebular hypothesis. The major points of each view are given and the models that are developed from these views are described. Possible applications of gamma ray astronomical observations to the question of the dynamic evolution of the solar system are discussed

  6. Gamma ray observations of the solar system

    Energy Technology Data Exchange (ETDEWEB)

    1981-01-01

    Two general categories are discussed concerning the evolution of the solar system: the dualistic view, the planetesimal approach and the monistic view, the nebular hypothesis. The major points of each view are given and the models that are developed from these views are described. Possible applications of gamma ray astronomical observations to the question of the dynamic evolution of the solar system are discussed.

  7. Gamma ray observations of the solar system

    Science.gov (United States)

    1981-01-01

    Two general categories are discussed concerning the evolution of the solar system: the dualistic view, the planetesimal approach; and the monistic view, the nebular hypothesis. The major points of each view are given and the models that are developed from these views are described. Possible applications of gamma ray astronomical observations to the question of the dynamic evolution of the solar system are discussed.

  8. THE CHROMOSPHERIC SOLAR LIMB BRIGHTENING AT RADIO, MILLIMETER, SUB-MILLIMETER, AND INFRARED WAVELENGTHS

    Energy Technology Data Exchange (ETDEWEB)

    De la Luz, V. [Conacyt—SCiESMEX, Instituto de Geofísica, Unidad Michoacán, Universidad Nacional Autónoma de México, Morelia, Michoacán, 58190, México (Mexico)

    2016-07-10

    Observations of the emission at radio, millimeter, sub-millimeter, and infrared wavelengths in the center of the solar disk validate the autoconsistence of semi-empirical models of the chromosphere. Theoretically, these models must reproduce the emission at the solar limb. In this work, we tested both the VALC and C7 semi-empirical models by computing their emission spectrum in the frequency range from 2 GHz to 10 THz at solar limb altitudes. We calculate the Sun's theoretical radii as well as their limb brightening. Non-local thermodynamic equilibrium was computed for hydrogen, electron density, and H{sup −}. In order to solve the radiative transfer equation, a three-dimensional (3D) geometry was employed to determine the ray paths, and Bremsstrahlung, H{sup −}, and inverse Bremsstrahlung opacity sources were integrated in the optical depth. We compared the computed solar radii with high-resolution observations at the limb obtained by Clark. We found that there are differences between the observed and computed solar radii of 12,000 km at 20 GHz, 5000 km at 100 GHz, and 1000 km at 3 THz for both semi-empirical models. A difference of 8000 km in the solar radii was found when comparing our results against the heights obtained from H α observations of spicules-off at the solar limb. We conclude that the solar radii cannot be reproduced by VALC and C7 semi-empirical models at radio—infrared wavelengths. Therefore, the structures in the high chromosphere provide a better measurement of the solar radii and their limb brightening as shown in previous investigations.

  9. THE CHROMOSPHERIC SOLAR LIMB BRIGHTENING AT RADIO, MILLIMETER, SUB-MILLIMETER, AND INFRARED WAVELENGTHS

    International Nuclear Information System (INIS)

    De la Luz, V.

    2016-01-01

    Observations of the emission at radio, millimeter, sub-millimeter, and infrared wavelengths in the center of the solar disk validate the autoconsistence of semi-empirical models of the chromosphere. Theoretically, these models must reproduce the emission at the solar limb. In this work, we tested both the VALC and C7 semi-empirical models by computing their emission spectrum in the frequency range from 2 GHz to 10 THz at solar limb altitudes. We calculate the Sun's theoretical radii as well as their limb brightening. Non-local thermodynamic equilibrium was computed for hydrogen, electron density, and H − . In order to solve the radiative transfer equation, a three-dimensional (3D) geometry was employed to determine the ray paths, and Bremsstrahlung, H − , and inverse Bremsstrahlung opacity sources were integrated in the optical depth. We compared the computed solar radii with high-resolution observations at the limb obtained by Clark. We found that there are differences between the observed and computed solar radii of 12,000 km at 20 GHz, 5000 km at 100 GHz, and 1000 km at 3 THz for both semi-empirical models. A difference of 8000 km in the solar radii was found when comparing our results against the heights obtained from H α observations of spicules-off at the solar limb. We conclude that the solar radii cannot be reproduced by VALC and C7 semi-empirical models at radio—infrared wavelengths. Therefore, the structures in the high chromosphere provide a better measurement of the solar radii and their limb brightening as shown in previous investigations.

  10. Infrared observations of RS CVn stars

    International Nuclear Information System (INIS)

    Berriman, G.; De Campli, W.M.; Werner, M.W.; Hatchett, S.P.

    1983-01-01

    Infrared photometry is presented of the RS CVn binary stars AR Lac (1.2-10 μm) and MM Her (1.2-3.5 μm) as they egressed from their primary and secondary eclipses; of the eclipsing systems RS CVn and Z Her at maximum light (1.2-10 μm) and of the non-eclipsing systems UX Ari and HR 1099 (1.2-10 μm). An analysis of these and published V data based on flux ratio diagrams (linear analogues of colour-colour diagrams) shows that G and K stars supply the infrared light of these systems. None of these systems shows infrared emission from circumstellar matter. (author)

  11. Single/Dual-Polarized Infrared Rectenna for Solar Energy Harvesting

    Directory of Open Access Journals (Sweden)

    S. H. Zainud-Deen

    2016-05-01

    Full Text Available Single and dual linearly-polarized receiving mode nanoantennas are designed for solar energy harvesting at 28.3 THz. The infrared rectennas are used to harvest the solar energy and converting it to electrical energy.  The proposed infrared rectenna is a thin dipole made of gold and printed on a silicon dioxide substrate. Different shapes of the dipole arms have been investigated for maximum collected energy. The two poles of the dipole have been determined in a rectangular, circular and rhombus shapes. The rectenna dipole is used to concentrate the electromagnetic energy into a small localized area at the inner tips of the gap between the dipole arms. The dimensions of the different dipole shapes are optimized for maximum near electric field intensity at a frequency of 28.3 THz. A Metal Insulator Metal (MIM diode is incorporated with the nanoantenna dipole to rectify the received energy. The receiving efficiency of the solar energy collector with integrated MIM diode has been investigated. A dual-polarized, four arms, rhombus shaped nanoantenna dipole for solar energy harvesting has been designed and optimized for 28.3 THz applications.

  12. Resource Letter OSE-1: Observing Solar Eclipses

    Science.gov (United States)

    Pasachoff, Jay M.; Fraknoi, Andrew

    2017-07-01

    This Resource Letter provides a guide to the available literature, listing selected books, articles, and online resources about scientific, cultural, and practical issues related to observing solar eclipses. It is timely, given that a total solar eclipse will cross the continental United States on August 21, 2017. The next total solar eclipse path crossing the U.S. and Canada will be on April 8, 2024. In 2023, the path of annularity of an annular eclipse will cross Mexico, the United States, and Canada, with partial phases visible throughout those countries.

  13. On the Incidence of Wise Infrared Excess Among Solar Analog, Twin, and Sibling Stars

    Energy Technology Data Exchange (ETDEWEB)

    Da Costa, A. D.; Martins, B. L. Canto; Lima Jr, J. E.; Silva, D. Freire da; Medeiros, J. R. De [Departamento de Física Teórica e Experimental, Universidade Federal do Rio Grande do Norte, Campus Universitário, Natal, RN, 59072-970 (Brazil); Leão, I. C. [European Southern Observatory, Karl-Schwarzschild-Str. 2, D-85748 Garching (Germany); Freitas, D. B. de, E-mail: dgerson@fisica.ufrn.br [Departamento de Física, Universidade Federal do Ceará, Caixa Postal 6030, Campus do Pici, 60455-900, Fortaleza, Ceará (Brazil)

    2017-03-01

    This study presents a search for infrared (IR) excess in the 3.4, 4.6, 12, and 22 μ m bands in a sample of 216 targets, composed of solar sibling, twin, and analog stars observed by the Wide-field Infrared Survey Explorer ( WISE ) mission. In general, an IR excess suggests the existence of warm dust around a star. We detected 12 μ m and/or 22 μ m excesses at the 3 σ level of confidence in five solar analog stars, corresponding to a frequency of 4.1% of the entire sample of solar analogs analyzed, and in one out of 29 solar sibling candidates, confirming previous studies. The estimation of the dust properties shows that the sources with IR excesses possess circumstellar material with temperatures that, within the uncertainties, are similar to that of the material found in the asteroid belt in our solar system. No photospheric flux excess was identified at the W1 (3.4 μ m) and W2 (4.6 μ m) WISE bands, indicating that, in the majority of stars of the present sample, no detectable dust is generated. Interestingly, among the 60 solar twin stars analyzed in this work, no WISE photospheric flux excess was detected. However, a null-detection excess does not necessarily indicate the absence of dust around a star because different causes, including dynamic processes and instrument limitations, can mask its presence.

  14. Solar Observations on Magneto-Convection

    Science.gov (United States)

    1989-05-31

    Technical Library National Solar Observatory Sunspot, NM 88349 Karl - Schwarzschild -Strasse 1 8046 Garching bei Mundhen Solar Observations On Magneto...Schmidt, Hermann-Ulrich Schmidt, Hans-Christoph Thomas (eds.) Max-Planck-Institut fir Physik und Astrophysik Institut fiur Astrophysik Karl ... Schwarzschild -St-. 1 D-8046 Garching, FklG 14TIS CRiA.&l DTIC TA. U~Jar,iou8:ed B ......... ... Distribution I -- Availability COcý----- Avail and or Dist special

  15. Observations spotted solar type stars in Pleiades

    International Nuclear Information System (INIS)

    Magnitskij, A.K.

    1987-01-01

    The september - october 1986 observations discovered periodic light variations in three solar type stars in the Pleiades cluster: Hz 296 (0.8 M Sun ), Hz152(0.91 M Sun ) and Hz739(1.15 M Sun ). Periods and amplitudes are accordingly 2 d and 0 m .11, 4 d .12 and 0 m .07, 2 d .70 and 0 m .05. Considerable light variations of these stars in Pleiades are due to the rotation of spotted stars. Contrast spots of solar type stars likely exist when stars are young and rapidly rotate

  16. New infrared telescopic observation of Vesta

    Science.gov (United States)

    Palomba, E.; D'Aversa, E.; Sato, T.; Longobardo, A.; Aoki, S.; Sindoni, G.; Oliva, F.

    2017-09-01

    In this work we present new telescopic observations of the Vesta asteroid made at the Subaru Telescope by using the COMICS IR spectrometer. We were able to obtain 5 different observations in 5 day, at two different epochs. The obtained spectra do not exhibit Reststrahlen bands and show only weak features attributable to the Christiansen peak and to the transparency feature compatible with a fine grain size regolith.

  17. OBSERVED ASTEROID SURFACE AREA IN THE THERMAL INFRARED

    Energy Technology Data Exchange (ETDEWEB)

    Nugent, C. R. [Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States); Mainzer, A.; Masiero, J.; Bauer, J.; Kramer, E.; Sonnett, S. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Wright, E. L. [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States); Grav, T. [Planetary Science Institute, Tucson, AZ (United States)

    2017-02-01

    The rapid accumulation of thermal infrared observations and shape models of asteroids has led to increased interest in thermophysical modeling. Most of these infrared observations are unresolved. We consider what fraction of an asteroid’s surface area contributes the bulk of the emitted thermal flux for two model asteroids of different shapes over a range of thermal parameters. The resulting observed surface in the infrared is generally more fragmented than the area observed in visible wavelengths, indicating high sensitivity to shape. For objects with low values of the thermal parameter, small fractions of the surface contribute the majority of thermally emitted flux. Calculating observed areas could enable the production of spatially resolved thermal inertia maps from non-resolved observations of asteroids.

  18. Evidence for Solar Cycle Influence on the Infrared Energy Budget and Radiative Cooling of the Thermosphere

    Science.gov (United States)

    Mlynczak, Martin G.; Martin-Torres, F. Javier; Marshall, B. Thomas; Thompson, R. Earl; Williams, Joshua; Turpin, TImothy; Kratz, D. P.; Russell, James M.; Woods, Tom; Gordley, Larry L.

    2007-01-01

    We present direct observational evidence for solar cycle influence on the infrared energy budget and radiative cooling of the thermosphere. By analyzing nearly five years of data from the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument, we show that the annual mean infrared power radiated by the nitric oxide (NO) molecule at 5.3 m has decreased by a factor of 2.9. This decrease is correlated (r = 0.96) with the decrease in the annual mean F10.7 solar index. Despite the sharp decrease in radiated power (which is equivalent to a decrease in the vertical integrated radiative cooling rate), the variability of the power as given in the standard deviation of the annual means remains approximately constant. A simple relationship is shown to exist between the infrared power radiated by NO and the F10.7 index, thus providing a fundamental relationship between solar activity and the thermospheric cooling rate for use in thermospheric models. The change in NO radiated power is also consistent with changes in absorbed ultraviolet radiation over the same time period.

  19. A method for combining passive microwave and infrared rainfall observations

    Science.gov (United States)

    Kummerow, Christian; Giglio, Louis

    1995-01-01

    Because passive microwave instruments are confined to polar-orbiting satellites, rainfall estimates must interpolate across long time periods, during which no measurements are available. In this paper the authors discuss a technique that allows one to partially overcome the sampling limitations by using frequent infrared observations from geosynchronous platforms. To accomplish this, the technique compares all coincident microwave and infrared observations. From each coincident pair, the infrared temperature threshold is selected that corresponds to an area equal to the raining area observed in the microwave image. The mean conditional rainfall rate as determined from the microwave image is then assigned to pixels in the infrared image that are colder than the selected threshold. The calibration is also applied to a fixed threshold of 235 K for comparison with established infrared techniques. Once a calibration is determined, it is applied to all infrared images. Monthly accumulations for both methods are then obtained by summing rainfall from all available infrared images. Two examples are used to evaluate the performance of the technique. The first consists of a one-month period (February 1988) over Darwin, Australia, where good validation data are available from radar and rain gauges. For this case it was found that the technique approximately doubled the rain inferred by the microwave method alone and produced exceptional agreement with the validation data. The second example involved comparisons with atoll rain gauges in the western Pacific for June 1989. Results here are overshadowed by the fact that the hourly infrared estimates from established techniques, by themselves, produced very good correlations with the rain gauges. The calibration technique was not able to improve upon these results.

  20. Near-infrared observations of the far-infrared source V region in NGC 6334

    International Nuclear Information System (INIS)

    Fischer, J.; Joyce, R.R.; Simon, M.; Simon, T.

    1982-01-01

    We have observed a very red near-infrared source at the center of NGC 6334 FIRS V, a far-infrared source suspected of variability by McBreen et al. The near-infrared source has deep ice and silicate absorption bands, and its half-power size at 20 μm is approx.15'' x 10''. Over the past 2 years we have observed no variability in the near-infrared flux. We have also detected an extended source of H 2 line emission in this region. The total luminosity in the H 2 v-1--0 S(1) line, uncorrected for extinction along the line of sight, is 0.3 L/sub sun/. Detection of emission in high-velocity wings of the J = 1--0 12 CO line suggests that the H 2 emission is associated with a supersonic gas flow

  1. Optical and infrared observations of SU tau

    Energy Technology Data Exchange (ETDEWEB)

    Doroshenko, V T; Efimov, Yu S; Rozenbush, A E; Terebizh, V Yu; Shenavrin, V I [Krymskaya Stantsiya GAISh (Ukrainian SSR); AN SSSR, Crimea. Krymskaya Astrofizicheskaya Observatoriya; AN Ukrainskoj SSR, Kiev. Glavnaya Astronomicheskaya Observatoriya)

    1978-02-01

    The results of the narrow-band (with the resolution of 50-100A) and UBVJK photometry and optical linear polarimetry of SU Tau in 1974-1977 are given. The polarization observed is mainly an interstellar one. An estimation of A/sub V/ approximately equal to 1.3/sup m/-2,0/sub m/ for the interstellar absorption from polarization data leads to the absolute magnitude M/sub V/ approximately equal to - 3/sup m/ which is typical for the RCrB stars. Nearer to the light maximum the continuous spectrum of the star corresponds to that of a type not later than G1 supergiant. An excess of energy in the spectral region from 1.25 to 2.2 ..mu..m may be associated with 1000 K blackbody radiation of the dust. The decrease of the brightness of the star is apparently due to the shielding effect of a cloud of graphite particles with sizes of about 0.06 ..mu..m. The light reduced by 3/sup m/ needs a surface density of about 1.5x10/sup 10/ cm/sup -2/. The change of light is accompanied by complicated changes in color. The reddening is the most in the rising branch of light, which is also typical for other RCrB type stars.

  2. The large scale infrared emission in the galactic plane - observations

    International Nuclear Information System (INIS)

    Okuda, H.

    1981-01-01

    Infrared radiation is deeply involved in a variety of matters and processes in the galaxy. Near infrared radiation is predominantly emitted by late type stars which include the major part of the mass in the Galaxy and hence govern its dynamics. Short wavelength radiation (UV and visible) emitted from early type stars is easily absorbed by dust around the stars themselves or by interstellar dust, and reemitted in middle or far infrared regions. A variety of emission lines, fine structure lines of neutral and ionized heavy elements, as well as many molecular lines are also clustered in the middle and far infrared regions. Since their line intensities are generally very weak, and, moreover, spectroscopic observations demand relatively difficult techniques in their detection, the surveys so far done have been limited mostly to continuum emission. This article compiles them and discusses briefly their implications to the structure of the Galaxy in its inner region. (Auth.)

  3. Integrated Access to Solar Observations With EGSO

    Science.gov (United States)

    Csillaghy, A.

    2003-12-01

    {\\b Co-Authors}: J.Aboudarham (2), E.Antonucci (3), R.D.Bentely (4), L.Ciminiera (5), A.Finkelstein (4), J.B.Gurman(6), F.Hill (7), D.Pike (8), I.Scholl (9), V.Zharkova and the EGSO development team {\\b Institutions}: (2) Observatoire de Paris-Meudon (France); (3) INAF - Istituto Nazionale di Astrofisica (Italy); (4) University College London (U.K.); (5) Politecnico di Torino (Italy), (6) NASA Goddard Space Flight Center (USA); (7) National Solar Observatory (USA); (8) Rutherford Appleton Lab. (U.K.); (9) Institut d'Astrophysique Spatial, Universite de Paris-Sud (France) ; (10) University of Bradford (U.K) {\\b Abstract}: The European Grid of Solar Observations is the European contribution to the deployment of a virtual solar observatory. The project is funded under the Information Society Technologies (IST) thematic programme of the European Commission's Fifth Framework. EGSO started in March 2002 and will last until March 2005. The project is categorized as a computer science effort. Evidently, a fair amount of issues it addresses are general to grid projects. Nevertheless, EGSO is also of benefit to the application domains, including solar physics, space weather, climate physics and astrophysics. With EGSO, researchers as well as the general public can access and combine solar data from distributed archives in an integrated virtual solar resource. Users express queries based on various search parameters. The search possibilities of EGSO extend the search possibilities of traditional data access systems. For instance, users can formulate a query to search for simultaneous observations of a specific solar event in a given number of wavelengths. In other words, users can search for observations on the basis of events and phenomena, rather than just time and location. The software architecture consists of three collaborating components: a consumer, a broker and a provider. The first component, the consumer, organizes the end user interaction and controls requests

  4. Solar Neutrino Observables Sensitive to Matter Effects

    Directory of Open Access Journals (Sweden)

    H. Minakata

    2012-01-01

    Full Text Available We discuss constraints on the coefficient AMSW which is introduced to simulate the effect of weaker or stronger matter potential for electron neutrinos with the current and future solar neutrino data. The currently available solar neutrino data leads to a bound AMSW=1.47+0.54−0.42(+1.88−0.82 at 1σ (3σ CL, which is consistent with the Standard Model prediction AMSW=1. For weaker matter potential (AMSW1, the bound is milder and is dominated by the day-night asymmetry of 8B neutrino flux recently observed by Super-Kamiokande. Among the list of observables of ongoing and future solar neutrino experiments, we find that (1 an improved precision of the day-night asymmetry of 8B neutrinos, (2 precision measurements of the low-energy quasi-monoenergetic neutrinos, and (3 the detection of the upturn of the 8B neutrino spectrum at low energies are the best choices to improve the bound on AMSW.

  5. High spectral resolution infrared observations of V1057 Cygni

    International Nuclear Information System (INIS)

    Hartmann, L.; Kenyon, S.J.

    1987-01-01

    High-resolution near-infrared spectra of V1057 Cygni obtained in 1986 with the KPNO 4-m Fourier transform spectrometer provide support for a previously proposed accretion disk model. The model predicts that the observed rotational broadening of spectral lines should be smaller in the infrared than in the optical. The present observations show that V1057 Cyg rotates more slowly at 2.3 microns than at 6000 A by an amount quantitatively consistent with the simple disk models. The absence of any radial velocity variations in either the infrared or optical spectral regions supports the suggestion that the accreted material arises from a remnant disk of protostellar material. 19 references

  6. Open Surface Solar Irradiance Observations - A Challenge

    Science.gov (United States)

    Menard, Lionel; Nüst, Daniel; Jirka, Simon; Maso, Joan; Ranchin, Thierry; Wald, Lucien

    2015-04-01

    The newly started project ConnectinGEO funded by the European Commission aims at improving the understanding on which environmental observations are currently available in Europe and subsequently providing an informational basis to close gaps in diverse observation networks. The project complements supporting actions and networking activities with practical challenges to test and improve the procedures and methods for identifying observation data gaps, and to ensure viability in real world scenarios. We present a challenge on future concepts for building a data sharing portal for the solar energy industry as well as the state of the art in the domain. Decision makers and project developers of solar power plants have identified the Surface Solar Irradiance (SSI) and its components as an important factor for their business development. SSI observations are crucial in the process of selecting suitable locations for building new plants. Since in-situ pyranometric stations form a sparse network, the search for locations starts with global satellite data and is followed by the deployment of in-situ sensors in selected areas for at least one year. To form a convincing picture, answers must be sought in the conjunction of these EO systems, and although companies collecting SSI observations are willing to share this information, the means to exchange in-situ measurements across companies and between stakeholders in the market are still missing. We present a solution for interoperable exchange of SSI data comprising in-situ time-series observations as well as sensor descriptions based on practical experiences from other domains. More concretely, we will apply concepts and implementations of the Sensor Web Enablement (SWE) framework of the Open Geospatial Consortium (OGC). The work is based on an existing spatial data infrastructure (SDI), which currently comprises metadata, maps and coverage data, but no in-situ observations yet. This catalogue is already registered in the

  7. Source brightness fluctuation correction of solar absorption fourier transform mid infrared spectra

    Directory of Open Access Journals (Sweden)

    T. Ridder

    2011-06-01

    Full Text Available The precision and accuracy of trace gas observations using solar absorption Fourier Transform infrared spectrometry depend on the stability of the light source. Fluctuations in the source brightness, however, cannot always be avoided. Current correction schemes, which calculate a corrected interferogram as the ratio of the raw DC interferogram and a smoothed DC interferogram, are applicable only to near infrared measurements. Spectra in the mid infrared spectral region below 2000 cm−1 are generally considered uncorrectable, if they are measured with a MCT detector. Such measurements introduce an unknown offset to MCT interferograms, which prevents the established source brightness fluctuation correction. This problem can be overcome by a determination of the offset using the modulation efficiency of the instrument. With known modulation efficiency the offset can be calculated, and the source brightness correction can be performed on the basis of offset-corrected interferograms. We present a source brightness fluctuation correction method which performs the smoothing of the raw DC interferogram in the interferogram domain by an application of a running mean instead of high-pass filtering the corresponding spectrum after Fourier transformation of the raw DC interferogram. This smoothing can be performed with the onboard software of commercial instruments. The improvement of MCT spectra and subsequent ozone profile and total column retrievals is demonstrated. Application to InSb interferograms in the near infrared spectral region proves the equivalence with the established correction scheme.

  8. Contribution of infrared observations to the study of supernovae remnants

    International Nuclear Information System (INIS)

    Douvion, Thomas

    2000-01-01

    This research thesis addresses the study of dust in young supernovae remnants observed in middle infrared, mainly by means of the ISOCAM instrument installed on the ISO satellite. The author first presents the supernovae physics and the studied young remnants, describes dusts and the main sites of formation and destruction, and outlines the difficulties and benefits of observations performed in the middle infrared. Then, the author reports acquired evidences related to the formation of dusts in supernovae, and the search for a millimetre emission by cold dust contained in regions which are not yet excited by the shock, in order to better assess the overall quantities created by supernovae. He reports the use of observations of dust and neon in Cassiopeia A to perform a diagnosis on the mixture of elements during the supernovae explosion [fr

  9. Infrared spectro-polarimeter on the Solar Flare Telescope at NAOJ/Mitaka

    Science.gov (United States)

    Sakurai, Takashi; Hanaoka, Yoichiro; Arai, Takehiko; Hagino, Masaoki; Kawate, Tomoko; Kitagawa, Naomasa; Kobiki, Toshihiko; Miyashita, Masakuni; Morita, Satoshi; Otsuji, Ken'ichi; Shinoda, Kazuya; Suzuki, Isao; Yaji, Kentaro; Yamasaki, Takayuki; Fukuda, Takeo; Noguchi, Motokazu; Takeyama, Norihide; Kanai, Yoshikazu; Yamamuro, Tomoyasu

    2018-05-01

    An infrared spectro-polarimeter installed on the Solar Flare Telescope at the Mitaka headquarters of the National Astronomical Observatory of Japan is described. The new spectro-polarimeter observes the full Sun via slit scans performed at two wavelength bands, one near 1565 nm for a Zeeman-sensitive spectral line of Fe I and the other near 1083 nm for He I and Si I lines. The full Stokes profiles are recorded; the Fe I and Si I lines give information on photospheric vector magnetic fields, and the helium line is suitable for deriving chromospheric magnetic fields. The infrared detector we are using is an InGaAs camera with 640 × 512 pixels and a read-out speed of 90 frames s-1. The solar disk is covered by two swaths (the northern and southern hemispheres) of 640 pixels each. The final magnetic maps are made of 1200 × 1200 pixels with a pixel size of 1{^''.}8. We have been carrying out regular observations since 2010 April, and have provided full-disk, full-Stokes maps, at the rate of a few maps per day, on the internet.

  10. Electromagnetic radiation energy arrangement. [coatings for solar energy absorption and infrared reflection

    Science.gov (United States)

    Lipkis, R. R.; Vehrencamp, J. E. (Inventor)

    1965-01-01

    A solar energy collector and infrared energy reflector is described which comprises a vacuum deposited layer of aluminum of approximately 200 to 400 Angstroms thick on one side of a substrate. An adherent layer of titanium with a thickness of between 800 and 1000 Angstroms is vacuum deposited on the aluminum substrate and is substantially opaque to solar energy and substantially transparent to infrared energy.

  11. Circumstellar envelopes seen in radio (OH masers) and in the infrared observations (IRAS)

    International Nuclear Information System (INIS)

    David, Pedro-Correia-de-Matos

    1992-01-01

    Intermediate mass stars, namely from one to nine solar masses, eject mass into the surrounding interstellar medium at high rates (up to 1/10000 solar masses per year) in their late stages of evolution on the so called asymptotic giant branch (AGB). Indeed, the presence of a circumstellar envelope (CSE) composed of dust and gas is one of the principal features of the objects on the AGB. Because of the high opacity at visible wavelength of the CSE, most of these objects can only be observed at infrared and radio frequencies. This study was undertaken using infrared and radio data from a large sample of CSE sources. The infrared data was obtained from the infrared astronomical satellite (IRAS) data base. For a selection of IRAS objects, radio observations were made of the OH maser at 1612 and 1667 MHz at the Nancay radio telescope, France. This work consists in two parts, one is theoretical in nature, the other observational. The theoretical part is concerned with the modeling of IRAS low resolution spectra (LRS catalog) and IRAS photometry through the use of a radiative transfer code. Confrontation between models and data has yielded such results as a better definition of the grain optical properties and the behavior of the CSE as it evolves. A model of a shock wave (a possible lifting engine of the CSE) propagating in the atmosphere of Mira stars (AGB) is described. On the observational side, a large number of objects has been surveyed for the presence of OH masers at 1612 and 1667 MHz. A statistical analysis has established more clearly the evolutionary status of CSE and the OH maser characteristics. A compiling of detection rates for the occurrence of masers, average location of these masing CSEs in the Galaxy, and OH maser characteristics is reported for use in future work. (author) [fr

  12. Radio and infrared observations of the faint nebula GM24

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, L F; Roth, M; Tapia, M; Canto, J; Persi, P; Ferrari-Toniolo, M

    1986-02-01

    The faint nebulosity GM24=PP85 listed by Parsamian and Petrosian (1979) was observed at infrared (1-10 ..mu..m) and radio (6 cm and CO line) wavelengths in the vicinity of the CO hot spot reported by Torrelles et al. (1983). The radio continuum (6 cm) emission from a spherically symmetrical HII region was detected with the Very Large Array. Its position coincides with the brightest part of the visible nebulosity and a 1-4 ..mu..m emission peak. Their infrared maps made at the Observatorio Astronomico Nacional de San Pedro Martir, show two additional (1-10 ..mu..m) peaks located at distances approx. 30 arc sec from the compact HII region, all surrounded by extended near infrared (1-4 ..mu..m) emission. A detailed CO (J=1 ..-->.. 0) map of the whole molecular cloud was also obtained with the University of Texas Millimeter - Wave Telescope. Their results are interpreted in terms of the recent formation of three massive stars, one of which, having developed an HII region, is at a slightly later phase of its evolution. The extended near infrared emission may arise in a reflection nebula similar to NGC 7538-Irs 9. 4 references.

  13. Solar Coronal Jets: Observations, Theory, and Modeling

    Science.gov (United States)

    Raouafi, N. E.; Patsourakos, S.; Pariat, E.; Young, P. R.; Sterling, A.; Savcheva, A.; Shimojo, M.; Moreno-Insertis, F.; Devore, C. R.; Archontis, V.; hide

    2016-01-01

    Chromospheric and coronal jets represent important manifestations of ubiquitous solar transients, which may be the source of signicant mass and energy input to the upper solar atmosphere and the solar wind. While the energy involved in a jet-like event is smaller than that of nominal solar ares and Coronal Mass Ejections (CMEs), jets share many common properties with these major phenomena, in particular, the explosive magnetically driven dynamics. Studies of jets could, therefore, provide critical insight for understanding the larger, more complex drivers of the solar activity. On the other side of the size-spectrum, the study of jets could also supply important clues on the physics of transients closeor at the limit of the current spatial resolution such as spicules. Furthermore, jet phenomena may hint to basic process for heating the corona and accelerating the solar wind; consequently their study gives us the opportunity to attack a broadrange of solar-heliospheric problems.

  14. Lyman continuum observations of solar flares

    Science.gov (United States)

    Machado, M. E.; Noyes, R. W.

    1978-01-01

    A study is made of Lyman continuum observations of solar flares, using data obtained by the EUV spectroheliometer on the Apollo Telescope Mount. It is found that there are two main types of flare regions: an overall 'mean' flare coincident with the H-alpha flare region, and transient Lyman continuum kernels which can be identified with the H-alpha and X-ray kernels observed by other authors. It is found that the ground level hydrogen population in flares is closer to LTE than in the quiet sun and active regions, and that the level of Lyman continuum formation is lowered in the atmosphere from a mass column density .000005 g/sq cm in the quiet sun to .0003 g/sq cm in the mean flare, and to .001 g/sq cm in kernels. From these results the amount of chromospheric material 'evaporated' into the high temperature region is derived, which is found to be approximately 10 to the 15th g, in agreement with observations of X-ray emission measures.

  15. Near-infrared to Mid-infrared Observations of Galaxy Mergers: NGC 2782 and NGC 7727

    Science.gov (United States)

    Onaka, Takashi; Nakamura, Tomohiko; Sakon, Itsuki; Wu, Ronin; Ohsawa, Ryou; Kaneda, Hidehiro; Lebouteiller, Vianney; Roellig, Thomas L.

    2018-01-01

    We present the results of near-infrared-to-mid-infrared (NIR-to-MIR) imaging and NIR spectroscopic observations of two galaxy mergers, NGC 2782 (Arp 215) and NGC 7727 (Arp 222), with the Infrared Camera on board AKARI. NGC 2782 shows extended MIR emission in the eastern side of the galaxy, which corresponds to the eastern tidal tail seen in the H I 21 cm map, while NGC 7727 shows extended MIR emission in the north of the galaxy, which is similar to the plumes seen in the residual image at the K-band after subtracting a galaxy model. Both extended structures are thought to have formed in association with their merger events. They show excess emission at 7–15 μm, which can be attributed to emission from polycyclic aromatic hydrocarbons (PAHs), while the observed spectral energy distributions (SEDs) decline longward of 24 μm, suggesting that very small grains (VSGs) are deficient. These characteristics of the observed MIR SED may be explained if PAHs are formed by fragmentation of VSGs during merger events. The star formation rate is estimated from the MIR PAH emission in the eastern tail region of NGC 2782 and it is in fair agreement with those estimated from Hα and [C II] 158 μm. MIR observations are efficient for the study of dust processing and structures formed during merger events.

  16. Single-step colloidal quantum dot films for infrared solar harvesting

    KAUST Repository

    Kiani, Amirreza

    2016-11-01

    Semiconductors with bandgaps in the near- to mid-infrared can harvest solar light that is otherwise wasted by conventional single-junction solar cell architectures. In particular, colloidal quantum dots (CQDs) are promising materials since they are cost-effective, processed from solution, and have a bandgap that can be tuned into the infrared (IR) via the quantum size effect. These characteristics enable them to harvest the infrared portion of the solar spectrum to which silicon is transparent. To date, IR CQD solar cells have been made using a wasteful and complex sequential layer-by-layer process. Here, we demonstrate ∼1 eV bandgap solar-harvesting CQD films deposited in a single step. By engineering a fast-drying solvent mixture for metal iodide-capped CQDs, we deposited active layers greater than 200 nm in thickness having a mean roughness less than 1 nm. We integrated these films into infrared solar cells that are stable in air and exhibit power conversion efficiencies of 3.5% under illumination by the full solar spectrum, and 0.4% through a simulated silicon solar cell filter.

  17. The development of an Infrared Environmental System for TOPEX Solar Panel Testing

    Science.gov (United States)

    Noller, E.

    1994-01-01

    Environmental testing and flight qualification of the TOPEX/POSEIDON spacecraft solar panels were performed with infrared (IR) lamps and a control system that were newly designed and integrated. The basic goal was more rigorous testing of the costly panels' new composite-structure design without jeopardizing their safety. The technique greatly reduces the costs and high risks of testing flight solar panels.

  18. VLBI observations of Infrared-Faint Radio Sources

    Science.gov (United States)

    Middelberg, Enno; Phillips, Chris; Norris, Ray; Tingay, Steven

    2006-10-01

    We propose to observe a small sample of radio sources from the ATLAS project (ATLAS = Australia Telescope Large Area Survey) with the LBA, to determine their compactness and map their structures. The sample consists of three radio sources with no counterpart in the co-located SWIRE survey (3.6 um to 160 um), carried out with the Spitzer Space Telescope. This rare class of sources, dubbed Infrared-Faint Radio Sources, or IFRS, is inconsistent with current galaxy evolution models. VLBI observations are an essential way to obtain further clues on what these objects are and why they are hidden from infrared observations: we will map their structure to test whether they resemble core-jet or double-lobed morphologies, and we will measure the flux densities on long baselines, to determine their compactness. Previous snapshot-style LBA observations of two other IFRS yielded no detections, hence we propose to use disk-based recording with 512 Mbps where possible, for highest sensitivity. With the observations proposed here, we will increase the number of VLBI-observed IFRS from two to five, soon allowing us to draw general conclusions about this intriguing new class of objects.

  19. Observing the Peripheral Burning of Cigarettes by an Infrared Technique

    Directory of Open Access Journals (Sweden)

    Liu C

    2014-12-01

    Full Text Available A modern infrared camera was used to observe the peripheral burning of cigarettes during puffing and smouldering. The computer-controlled infrared system captured thermal images with recording rates up to 50 Hz at 8-bit (256-colour resolution. The response time was less than 0.04 s at ca. 780 °C. The overall performance of the system was superior to most infrared systems used in previously reported investigations. The combined capacity allowed us to capture some faster, smaller high-temperature burning events on the periphery of a cigarette during puffing, which was first described by Egertion et al. in 1963 using an X-ray method. These transient burning events were caused by tobacco shreds near the coal surface experiencing the maximum air influx. The temperature of these transient burning events could be ca. 200 to 250 °C higher than the average peripheral temperature of the cigarette. The likelihood of these high-temperature burning events occurring during smouldering was significantly less. Some other details of the cigarette's combustion were also observed with improved simplicity and clarity.

  20. Observational Investigation of Solar Interior and Atmosphere

    Science.gov (United States)

    Kuhn, Jeffrey R.

    2003-01-01

    The Imaging Vector Magnetograph (IVM) has been modified to make it easier to observe at more than one spectral line. The cell holding the blocking filter has been replaced by a four-position filter wheel, so that changing to a different line is a matter of a few minutes rather than the several hours it used to take to disassemble the cell and install a new filter. Three new filters have been obtained, for Na 1589.6 nm, Fe 1630.25 nm, and H 1656.3 nm. The new filters have better bandpass profiles than the ones they replaced: somewhat wider, with flatter tops and steeper wings. This results in a reduction of parasitic light coming from adjacent Fabry-Perot orders, from seven percent to about two percent, and flattens the apparent continuum. The Mees CCD Imaging Spectrograph (MCCD) was upgraded under this grant, with a new control computer and data system. The camera was replaced with a faster, larger-format frame-transfer camera. Final integration of the upgrades is not yet complete, but tests indicate that the system cadence will be improved by a factor of five to ten, while increasing the spatial coverage by a factor of two (depending on observation options). Synoptic observations with the IVM and MCCD continue to be conducted daily, to the extent permitted by the fact that we have a single observer responsible for the observations. The older Haleakala Stokes Polarimeter is also used to make a daily vector magnetogram, normally of the region selected by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) duty scientists. This instrument, however, is showing its age to the extent that its maintenance is becoming something of a challenge. We also run a white light full-disk imager and a video H alpha prominence camera, continuously during times of observations. Of particular interest, we obtained rapid-cadence observations of the 2003 July 15 white light flare with both the IVM and MCCD. The vector magnetograms show no obvious difference between the

  1. Direct observations of low-energy solar electrons associated with a type 3 solar radio burst

    Science.gov (United States)

    Frank, L. A.; Gurnett, D. A.

    1972-01-01

    On 6 April 1971 a solar X-ray flare and a type 3 solar radio noise burst were observed with instrumentation on the eccentric-orbiting satellite IMP 6. The type 3 solar radio noise burst was detected down to a frequency of 31 kHz. A highly anisotropic packet of low-energy solar electron intensities arrived at the satellite approximately 6000 seconds after the onset of the solar flare. This packet of solar electron intensities was observed for 4200 seconds. Maximum differential intensities of the solar electrons were in the energy range of one to several keV. The frequency drift rate of the type 3 radio noise at frequencies below 178 kHz also indicated an average particle speed corresponding to that of a 3-keV electron. The simultaneous observations of these solar electron intensities and of the type 3 solar radio burst are presented, and their interrelationships are explored.

  2. MIRIS observation of near-infrared diffuse Galactic light

    Science.gov (United States)

    Onishi, Yosuke; Sano, Kei; Matsuura, Shuji; Jeong, Woong-Seob; Pyo, Jeonghyun; Kim, Il-Jong; Seo, Hyun Jong; Han, Wonyong; Lee, DaeHee; Moon, Bongkon; Park, Wonkee; Park, Younsik; Kim, MinGyu; Matsumoto, Toshio; Matsuhara, Hideo; Nakagawa, Takao; Tsumura, Kohji; Shirahata, Mai; Arai, Toshiaki; Ienaka, Nobuyuki

    2018-06-01

    We report near-infrared (IR) observations of high Galactic latitude clouds to investigate diffuse Galactic light (DGL), which is starlight scattered by interstellar dust grains. The observations were performed at 1.1 and 1.6 μm with a wide-field camera instrument, the Multi-purpose Infra-Red Imaging System (MIRIS) onboard the Korean satellite STSAT-3. The DGL brightness is measured by correlating the near-IR images with a far-IR 100 μm map of interstellar dust thermal emission. The wide-field observation of DGL provides the most accurate DGL measurement achieved to-date. We also find a linear correlation between optical and near-IR DGL in the MBM32 field. To study interstellar dust properties in MBM32, we adopt recent dust models with and without μm-sized very large grains and predict the DGL spectra, taking into account the reddening effect of the interstellar radiation field. The result shows that the observed color of the near-IR DGL is closer to the model spectra without very large grains. This may imply that dust growth in the observed MBM32 field is not active owing to the low density of its interstellar medium.

  3. Molecular action mechanisms of solar infrared radiation and heat on human skin.

    Science.gov (United States)

    Akhalaya, M Ya; Maksimov, G V; Rubin, A B; Lademann, J; Darvin, M E

    2014-07-01

    The generation of ROS underlies all solar infrared-affected therapeutic and pathological cutaneous effects. The signaling pathway NF-kB is responsible for the induced therapeutic effects, while the AP-1 for the pathological effects. The different signaling pathways of infrared-induced ROS and infrared-induced heat shock ROS were shown to act independently multiplying the influence on each other by increasing the doses of irradiation and/or increasing the temperature. The molecular action mechanisms of solar infrared radiation and heat on human skin are summarized and discussed in detail in the present paper. The critical doses are determined. Protection strategies against infrared-induced skin damage are proposed. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Solar flare loops observations and interpretations

    CERN Document Server

    Huang, Guangli; Ji, Haisheng; Ning, Zongjun

    2018-01-01

    This book provides results of analysis of typical solar events, statistical analysis, the diagnostics of energetic electrons and magnetic field, as well as the global behavior of solar flaring loops such as their contraction and expansion. It pays particular attention to analyzing solar flare loops with microwave, hard X-ray, optical and EUV emissions, as well as the theories of their radiation, and electron acceleration/transport. The results concerning influence of the pitch-angle anisotropy of non-thermal electrons on their microwave and hard X-ray emissions, new spectral behaviors in X-ray and microwave bands, and results related to the contraction of flaring loops, are widely discussed in the literature of solar physics. The book is useful for graduate students and researchers in solar and space physics.

  5. Observed ices in the Solar System

    Science.gov (United States)

    Clark, Roger N.; Grundy, Will; Carlson, Robert R.; Noll, Keith; Gudipati, Murthy; Castillo-Rogez, Julie C.

    2013-01-01

    Ices have been detected and mapped on the Earth and all planets and/or their satellites further from the sun. Water ice is the most common frozen volatile observed and is also unambiguously detected or inferred in every planet and/or their moon(s) except Venus. Carbon dioxide is also extensively found in all systems beyond the Earth except Pluto although it sometimes appears to be trapped rather than as an ice on some objects. The largest deposits of carbon dioxide ice is on Mars. Sulfur dioxide ice is found in the Jupiter system. Nitrogen and methane ices are common beyond the Uranian system. Saturn’s moon Titan probably has the most complex active chemistry involving ices, with benzene (C6H6) and many tentative or inferred compounds including ices of Cyanoacetylene (HC3N), Toluene (C7H8), Cyanogen (C2N2), Acetonitrile (CH3CN), H2O, CO2, and NH3. Confirming compounds on Titan is hampered by its thick smoggy atmosphere. Ammonia was predicted on many icy moons but is notably absent among the definitively detected ices with the possible exception of Enceladus. Comets, storehouses of many compounds that could exist as ices in their nuclei, have only had small amounts of water ice definitively detected on their surfaces. Only one asteroid has had a direct detection of surface water ice, although its presence can be inferred in others. This chapter reviews some of the properties of ices that lead to their detection, and surveys the ices that have been observed on solid surfaces throughout the Solar System.

  6. Solar neutrino observations and neutrino oscillations

    International Nuclear Information System (INIS)

    Kuo, T.K.; Pantaleone, J.

    1990-01-01

    The results of recent Kamiokande-II and 37 Cl solar-neutrino experiments are quantitatively analyzed assuming the Mikheyev-Smirnov-Wolfenstein solution to the solar-neutrino problem. It is found that the parameter region known as the ''large mass'' solution to the solar-neutrino problem is disfavored by a little more than 1 σ while the ''small mass'' and ''large angle'' solutions are in good agreement at this level. The implications on this analysis from time variations in the data are discussed

  7. Molecular line observations of infrared dark clouds in the galaxy

    Science.gov (United States)

    Finn, Susanna C.

    Although massive stars play many important roles in the universe, their formation is poorly understood. Recently, a class of interstellar clouds known as Infrared Dark Clouds (IRDCs) has been identified as likely progenitors of massive stars and clusters. These clouds are dense (nH 2 > 105 cm--3), cold (T Nessie Nebula," an extreme case of a filamentary IRDC, with predictions from the theory of the fluid instability and then expand the sample to other filamentary IRDCs. The observations are consistent with theoretical predictions of clump spacing, clump masses, and linear mass density. Fragmentation of filaments due to the sausage instability might be the dominant mode of star formation in the Universe.

  8. Ultraviolet and infrared emission from lightning discharges observed at Aragats

    International Nuclear Information System (INIS)

    Chilingarian, A.; Karapetyan, T.; Pokhsraryan, D.; Bogomolov, V.; Garipov, G.; Panasyuk, M.; Svertilov, S.; Saleev, K.

    2016-01-01

    The ultraviolet and infrared optical sensors previously used at RELEC space missions were installed at the high altitude research station Aragats at 3200 m above the sea level. The spectral composition and temporal structure of the recorded optical signals and measurements of the electrostatic field and atmospheric discharges obtained by “fast” and “slow” field sensors have been compared. Measurements of lightning and related to them phenomena observed at the mountain altitude and on board of orbiting satellites are compared. (author)

  9. Ionospheric Caustics in Solar Radio Observations

    Science.gov (United States)

    Koval, A.; Chen, Y.; Stanislavsky, A.

    2016-12-01

    The Earth ionosphere possesses by natural focusing and defocusing effects on radio waves due to presence of variable ionospheric irregularities which could act like convergent and divergent lenses on incident radiation. In particular, the focusing of emission from the Sun was firstly detected on the Nançay Decameter Array dynamic spectra in the 1980s. On time-frequency spectrograms the intensity variations form specific structures different from well-known solar radio bursts and clearly distinguishing on a background of solar radiation. Such structures have been identified as ionospheric caustics (ICs) and considered to be the result of radio waves refraction on medium scale travelling ionospheric disturbances (MSTIDs). Although nowadays the ICs are registered by different radio observatories due to augmentation of low-frequency radio telescopes, the most recent papers devoted to ICs in solar radio records date back to the 1980s. In this study, we revisit the ICs issue with some new results by conducting a statistical analysis of occurrence rate of ICs in solar dynamic spectra in meter-decameter wavelength range for long continuous period (15 years). The seasonal variations in ICs appearance have been found for the first time. Besides, we report the possible solar cycle dependence of ICs emergence. The radio waves propagation in the ionosphere comprising MSTIDs will be considered. The present research renews the subject of ICs in the low-frequency solar radio astronomy after about 35-year letup.

  10. The nature of cometary dust as determined from infrared observations

    Science.gov (United States)

    Swamy, K. S. Krishna; Sandford, Scott A.; Allamandola, Louis J.; Witteborn, Fred C.; Bregman, Jesse D.

    1989-01-01

    The infrared measurements of comets, the compositional information available from interplanetary dust particles (IDPs), and the recent results of flybys to Comet Halley can help in restricting the nature and composition of cometary dust models (c.f., Proceedings of the 20th ESLAB Symposium on Exploration of Halley's Comet, 1986). Researchers tried to incorporate some of these results into a coherent model to account for the observed cometary infrared emission. The presence of 10 and 3.4 micron features in Comet Halley (c.f. Bregman et al. 1987; Wickramasinghe and Allen 1986) indicated the presence of at least two components in the grain material, namely silicates and some form of amorphous carbon. These two components could reside in separate grains or may be parts of composite particles. Both these cases have been considered (see Krishna Swamy el a. 1988a, 1988b). In the absence of refractive index data for cometary analogs, the authors used the optical constants of olivine-rich lunar material 12009.48 (Perry et al. 1972) for the infrared region and that of alpha:C-H film for amorphous carbon (angus et al. 1986). For the visible region, a value of m = 1.38-0.39i was used for the silicates, and values published by Arakawa et al. (1985) were used for the amorphous carbon. These materials should give a representative behavior of the expected results. The model results were compared to observational data. The strength of the 3.4 micron and 10 micron features relative to the adjacent continuum, as well as the slope of the continuum between 2500 and 1250 cm(exp -1) (4 to 8 microns), were used as criteria for comparison. Model calculations with alpha approx. equals -3.5, and also the size distribution function inferred for Comet Halley, with a mass fraction (X) of silicate to amorphous carbon grains of about 40 to 1 can fit the data. A good match is obtained for the infrared spectra of Comets Halley and West from a 40 to 1 mixture of silicate and amorphous carbon grains

  11. 8 years of Solar Spectral Irradiance Observations from the ISS with the SOLAR/SOLSPEC Instrument

    Science.gov (United States)

    Damé, L.; Bolsée, D.; Meftah, M.; Irbah, A.; Hauchecorne, A.; Bekki, S.; Pereira, N.; Cessateur, G.; Marchand, M.; Thiéblemont, R.; Foujols, T.

    2016-12-01

    Accurate measurements of Solar Spectral Irradiance (SSI) are of primary importance for a better understanding of solar physics and of the impact of solar variability on climate (via Earth's atmospheric photochemistry). The acquisition of a top of atmosphere reference solar spectrum and of its temporal and spectral variability during the unusual solar cycle 24 is of prime interest for these studies. These measurements are performed since April 2008 with the SOLSPEC spectro-radiometer from the far ultraviolet to the infrared (166 nm to 3088 nm). This instrument, developed under a fruitful LATMOS/BIRA-IASB collaboration, is part of the Solar Monitoring Observatory (SOLAR) payload, externally mounted on the Columbus module of the International Space Station (ISS). The SOLAR mission, with its actual 8 years duration, will cover almost the entire solar cycle 24. We present here the in-flight operations and performances of the SOLSPEC instrument, including the engineering corrections, calibrations and improved know-how procedure for aging corrections. Accordingly, a SSI reference spectrum from the UV to the NIR will be presented, together with its UV variability, as measured by SOLAR/SOLSPEC. Uncertainties on these measurements and comparisons with other instruments will be briefly discussed.

  12. The effects of electron and proton radiation on GaSb infrared solar cells

    Science.gov (United States)

    Gruenbaum, P. E.; Avery, J. E.; Fraas, L. M.

    1991-01-01

    Gallium antimonide (GaSb) infrared solar cells were exposed to 1 MeV electrons and protons up to fluences of 1 times 10(exp 15) cm (-2) and 1 times 10(exp 12) cm (-2) respectively. In between exposures, current voltage and spectral response curves were taken. The GaSb cells were found to degrade slightly less than typical GaAs cells under electron irradiation, and calculations from spectral response curves showed that the damage coefficient for the minority carrier diffusion length was 3.5 times 10(exp 8). The cells degraded faster than GaAs cells under proton irradiation. However, researchers expect the top cell and coverglass to protect the GaSb cell from most damaging protons. Some annealing of proton damage was observed at low temperatures (80 to 160 C).

  13. Infrared observations of the dark matter lens candidate Q2345+007

    Science.gov (United States)

    Mcleod, Brian; Rieke, Marcia; Weedman, Daniel

    1994-01-01

    Deep K-band observations are presented of the double image quasar Q2345+007. This has the largest separation (7.1 sec) of any quasar image pair considered as gravitationally lensed, so the required lens is massive (10(exp 13) solar masses). No lens has been detected in previous deep images at visible wavelengths, and we find no lens to limiting K magnitude 20.0 in the infrared image. This constrains any lens to being much less luminous than brightest cluster galaxies, while the lens must be much more massive than such galaxies to produce the observed separation. Because spectral data indicate exceptional intrinsic similarity in the quasar image components, this pair remains as the most intriguing example of an observed configuration requiring the presence of massive, concentrated dark matter acting as a gravitational lens.

  14. Solar-wind minor ions: recent observations

    International Nuclear Information System (INIS)

    Bame, S.J.

    1982-01-01

    During the years following the Solar Wind Four Conference at Burghausen our knowledge of the solar wind ion composition and dynamics has grown. There have been some surprises, and our understanding of the evolution of the solar wind has been improved. Systematic studies have shown that the minor ions generally travel with a common bulk speed and have temperatures roughly proportional to their masses. It has been determined that the 3 He ++ content varies greatly; 3 He ++ / 4 He ++ ranges from as high as 10 2 values to below 2 x 10 - 4 . In some solar wind flows which can be related to energetic coronal events, the minor ions are found in unusual ionization states containing Fe 16 + as a prominent ion, showing that the states were formed at unusually high temperatures. Unexpectedly, in a few flows substantial quantities of 4 He + have been detected, sometimes with ions identifiable as O 2 + and O 3 + . Surprisingly, in some of these examples the ionization state is mixed showing that part of the plasma escaped the corona without attaining the usual million-degree temperatures while other parts were heated more nearly in the normal manner. Additionally, detailed studies of the minor ions have increased our understanding of the coronal expansion. For example, such studies have contributed to identifying near equatorial coronal streamers as the source of solar wind flows between high speed streams

  15. Optical, infrared and radio astronomy from techniques to observation

    CERN Document Server

    Poggiani, Rosa

    2017-01-01

    This textbook presents the established sciences of optical, infrared, and radio astronomy as distinct research areas, focusing on the science targets and the constraints that they place on instrumentation in the different domains. It aims to bridge the gap between specialized books and practical texts, presenting the state of the art in different techniques. For each type of astronomy, the discussion proceeds from the orders of magnitude for observable quantities that drive the building of instrumentation and the development of advanced techniques. The specific telescopes and detectors are then presented, together with the techniques used to measure fluxes and spectra. Finally, the instruments and their limits are discussed to assist readers in choice of setup, planning and execution of observations, and data reduction. The volume also includes worked examples and problem sets to improve student understanding; tables and figures in chapters summarize the state of the art of instrumentation and techniques.

  16. Glow discharge, its sensitivity to infra-red radiation. Observations made during the testing of multiwire proportional chambers

    International Nuclear Information System (INIS)

    Marsh, J.B.; Souten, K.H.; O'Hagan, B.

    1979-05-01

    It has been shown that under glow discharge conditions, multiwire proportional chambers are sensitive to infra-red radiation. Discharge current measurements and light change measurements have been made and the effect of the input window on the output signal and the importance of the finish of the anode and HT wires have been investigated. From these observations it would appear that a glow discharge in the form detailed in this report is sensitive to infra-red radiation though work is still required to optimise the parameters of such a device for IR detection or solar cell technology. (UK)

  17. Near-infrared observations of IRAS minisurvey galaxies

    International Nuclear Information System (INIS)

    Carico, D.P.; Soifer, B.T.; Elias, J.H.; Matthews, K.; Neugebauer, G.; Beichman, C.; Persson, C.J.; Persson, S.E.

    1987-01-01

    Near infrared photometry at J, H, and K was obtained for 82 galaxies from the IRAS minisurvey. The near infrared colors of these galaxies cover a larger range in J-H and H-K than do normal field spiral galaxies, and evidence is presented of a tighter correlation between the near and far infrared emission in far infrared bright galaxies than exists between the far infrared and the visible emission. These results suggest the presence of dust in the far infrared bright galaxies, with hot dust emission contributing to the 2.2 micron emission, and extinction by dust affecting both the near infrared colors and the visible luminosities. In addition, there is some indication that the infrared emission in many of the minisurvey galaxies is coming from a strong nuclear component

  18. Ancient Chinese observations of physical phenomena attending solar eclipses

    International Nuclear Information System (INIS)

    Wang, P.K.; Siscoe, G.L.

    1980-01-01

    The realization that solar activity probably undergoes changes in qualitative character on time scales greater than the 11 or 22 year cycle but short compared to the duration of recorded history gives renewed importance to historical documents describing the state of solar activity. Modern eclipse observation reveal the presence of solar acitivity through the appearance of coronal structures and prominences. It has been widely remarked that eclipse records prior to the 18th century are uniformly silent on these conspicuous solar eclipse features, raising the possibility, however unlikely, that a change in solar activity has occurred which rendered them only recently noticeable. We present here material from ancient Chinese sources, primarily astrological, that describe phenomena attending solar eclipses that are almost certainly coronal structures and prominences. Thus, these aspects of the present character of solar activity have apparently occurred at other times in history, if not continuously. (orig.)

  19. Infrared and optical observations of Nova Mus 1983

    International Nuclear Information System (INIS)

    Whitelock, P.A.; Carter, B.S.; Feast, M.W.; Glass, I.S.; Laney, D.; Menzies, J.W.

    1984-01-01

    Extensive optical (UBVRI) and infrared (JHKL) photometry of Nova Mus 1983 obtained over a period of 300 days is tabulated. Infrared and optical spectra are described. Although by classical definition this was a fast nova its later development was slower than for typical objects of this class. Surprisingly the development of infrared thermal dust emission did not occur. Throughout the period covered, the infrared emission was characteristic of a bound-free plus free-free plasma continuum with emission lines. (author)

  20. Infrared observations of gravitational-wave sources in Advanced LIGO's second observing run

    Science.gov (United States)

    Pound Singer, Leo; Kasliwal, Mansi; Lau, Ryan; Cenko, Bradley; Global Relay of Observatories Watching Transients Happen (GROWTH)

    2018-01-01

    Advanced LIGO observed gravitational waves (GWs) from a binary black hole merger in its first observing run (O1) in September 2015. It is anticipated that LIGO and Virgo will soon detect the first binary neutron star mergers. The most promising electromagnetic counterparts to such events are kilonovae: fast, faint transients powered by the radioactive decay of the r-process ejecta. Joint gravitational-wave and electromagnetic observations of such transients hold the key to many longstanding problems, from the nature of short GRBS to the cosmic production sites of the r-process elements to "standard siren" cosmology. Due to the large LIGO/Virgo error regions of 100 deg2, synoptic survey telescopes have dominated the search for LIGO counterparts. Due to the paucity of infrared instruments with multi-deg2 fields of view, infrared observations have been lacking. Near-infrared emission should not only be a more robust signature of kilonovae than optical emission (independent of viewing angle), but should also be several magnitudes brighter and be detectable for much longer, weeks after merger rather than days. In Advanced LIGO's second observing run, we used the FLAMINGOS-2 instrument on Gemini-South to hunt for the near-infrared emission from GW sources by targeted imaging of the most massive galaxies in the LIGO/Virgo localization volumes. We present the results of this campaign, rates, and interpretation of our near-infrared imaging and spectroscopy. We show that leveraging large-scale structure and targeted imaging of the most massive ~10 galaxies in a LIGO/Virgo localization volume may be a surprisingly effective strategy to find the electromagnetic counterpart.

  1. Solar radiation observation stations updated to 1979

    Energy Technology Data Exchange (ETDEWEB)

    Carter, E.A.; Cristina, J.R.; Williams, B.B.

    1979-04-01

    The type of sensing and recording equipment for 420 stations in the US are listed alphabetically by states. The stations are divided according to whether or not they are in the basic National Weather Service, NOAA, network. Reports of summarized solar radiation data are listed in an appendix. (MHR)

  2. Reservoirs for Comets: Compositional Differences Based on Infrared Observations

    Science.gov (United States)

    Disanti, Michael A.; Mumma, Michael J.

    Tracing measured compositions of comets to their origins continues to be of keen interest to cometary scientists and to dynamical modelers of Solar System formation and evolution. This requires building a taxonomy of comets from both present-day dynamical reservoirs: the Kuiper Belt (hereafter KB), sampled through observation of ecliptic comets (primarily Jupiter Family comets, or JFCs), and the Oort cloud (OC), represented observationally by the long-period comets and by Halley Family comets (HFCs). Because of their short orbital periods, JFCs are subjected to more frequent exposure to solar radiation compared with OC comets. The recent apparitions of the JFCs 9P/Tempel 1 and 73P/Schwassmann-Wachmann 3 permitted detailed observations of material issuing from below their surfaces—these comets added significantly to the compositional database on this dynamical class, which is under-represented in studies of cometary parent volatiles. This chapter reviews the latest techniques developed for analysis of high-resolution spectral observations from ˜2-5 μm, and compares measured abundances of native ices among comets. While no clear compositional delineation can be drawn along dynamical lines, interesting comparisons can be made. The sub-surface composition of comet 9P, as revealed by the Deep Impact ejecta, was similar to the majority of OC comets studied. Meanwhile, 73P was depleted in all native ices except HCN, similar to the disintegrated OC comet C/1999 S4 (LINEAR). These results suggest that 73P may have formed in the inner giant planets' region while 9P formed farther out or, alternatively, that both JFCs formed farther from the Sun but with 73P forming later in time.

  3. On the Physical Significance of Infra-red Corrections to Inflationary Observables

    CERN Document Server

    Bartolo, N; Pietroni, M; Riotto, Antonio; Seery, D

    2008-01-01

    Inflationary observables, like the power spectrum, computed at one- and higher-order loop level seem to be plagued by large infra-red corrections. In this short note, we point out that these large infra-red corrections appear only in quantities which are not directly observable. This is in agreement with general expectations concerning infra-red effects.

  4. Observation of solar wind with radio-star scintillation

    International Nuclear Information System (INIS)

    Watanabe, Takashi

    1974-01-01

    Large solar flares occurred in groups in early August 1972, and many interesting phenomena were observed. The solar wind condition during this period, obtained by scintillation observation, is reviewed. The velocity of solar wind has been determined from the observation of interplanetary space scintillation at Toyokawa, Fujigamine and Sugadaira. Four to ten radio wave sources were observed for ten minutes at each southing every day. Strong earth magnetic storm and the Forbush decrease of cosmic ray were observed during the period from August 3rd to 7th. Pioneer 9 observed a solar wind having the maximum velocity as high as 1,100 km/sec, and HEOS-II observed a solar wind having the velocity close to 2,000 km/sec. On the other hand, according to the scintillation of 3C-48 and 3C-144, the velocity of solar wind passing in the interplanetary space on the westside of the earth was only 300 to 400 km/sec. Therefore it is considered that the condition of solar wind on the east side of the earth differs from that on the west side of the earth. Pioneer 9 observed the pass of a shock wave on August 9th. With all radio wave sources, high velocity solar wind was observed and Pioneer 6 positioned on the west side of the earth also observed it. The thickness of this shock wave is at least 0.3 AU. Discussion is made on the cause for the difference between the asymmetric shock wave in the direction of south-west and symmetrical shock wave. The former may be blast wave, and the latter may be piston driven shock wave and the like. (Iwakiri, K.)

  5. Polarimetry of Solar System Objects: Observations vs. Models

    Science.gov (United States)

    Yanamandra-Fisher, P. A.

    2014-04-01

    The overarching goals for the remote sensing and robotic exploration of planetary systems are: (1) understanding the formation of planetary systems and their diversity; and (2) search for habitability. Since all objects have unique polarimetric signatures inclusion of spectrophotopolarimetry as a complementary approach to standard techniques of imaging and spectroscopy, provides insight into the scattering properties of the planetary media. Specifically, linear and circular polarimetric signatures of the object arise from different physical processes and their study proves essential to the characterization of the object. Linear polarization of reflected light by various solar system objects provides insight into the scattering characteristics of atmospheric aerosols and hazes? and surficial properties of atmosphereless bodies. Many optically active materials are anisotropic and so their scattering properties differ with the object's principal axes (such as dichroic or birefringent materials) and are crystalline in structure instead of amorphous, (eg., the presence of olivines and silicates in cometary dust and circumstellar disks? Titan, etc.). Ices (water and other species) are abundant in the system indicated in their near - infrared spectra. Gas giants form outside the frost line (where ices condense), and their satellites and ring systems exhibit signature of water ice? clathrates, nonices (Si, C, Fe) in their NIR spectra and spectral dependence of linear polarization. Additionally, spectral dependence of polarization is important to separate the macroscopic (bulk) properties of the scattering medium from the microscopic (particulate) properties of the scattering medium. Circular polarization, on the other hand, is indicative of magnetic fields and biologically active molecules, necessary for habitability. These applications suffer from lack of detailed observations, instrumentation, dedicated missions and numericalretrieval methods. With recent discoveries and

  6. Observed solar near UV variability: A contribution to variations of the solar constant

    International Nuclear Information System (INIS)

    London, J.; Pap, J.; Rottman, G.J.

    1989-01-01

    Continuous Measurements of the Solar UV have been made by an instrument on the Solar Mesosphere Explorer (SME) since October 1981. The results for the wavelength interval 200 to 300 nm show an irradiance decrease to a minimum in early 1987 and a subsequent increase to mid-April 1989. The observed UV changes during part of solar cycles 21 to 22 represent approx. 35 percent (during the decreasing phase) and 25 percent (during the increasing phase) of the observed variations of the solar constant for the same time period as the SME measurements

  7. Water in the Early Solar System: Infrared Studies of Aqueously Altered and Minimally Processed Asteroids

    Science.gov (United States)

    McAdam, Margaret M.

    This thesis investigates connections between low albedo asteroids and carbonaceous chondrite meteorites using spectroscopy. Meteorites and asteroids preserve information about the early solar system including accretion processes and parent body processes active on asteroids at these early times. One process of interest is aqueous alteration. This is the chemical reaction between coaccreted water and silicates producing hydrated minerals. Some carbonaceous chondrites have experienced extensive interactions with water through this process. Since these meteorites and their parent bodies formed close to the beginning of the Solar System, these asteroids and meteorites may provide clues to the distribution, abundance and timing of water in the Solar nebula at these times. Chapter 2 of this thesis investigates the relationships between extensively aqueously altered meteorites and their visible, near and mid-infrared spectral features in a coordinated spectral-mineralogical study. Aqueous alteration is a parent body process where initially accreted anhydrous minerals are converted into hydrated minerals in the presence of coaccreted water. Using samples of meteorites with known bulk properties, it is possible to directly connect changes in mineralogy caused by aqueous alteration with spectral features. Spectral features in the mid-infrared are found to change continuously with increasing amount of hydrated minerals or degree of alteration. Building on this result, the degrees of alteration of asteroids are estimated in a survey of new asteroid data obtained from SOFIA and IRTF as well as archived the Spitzer Space Telescope data. 75 observations of 73 asteroids are analyzed and presented in Chapter 4. Asteroids with hydrated minerals are found throughout the main belt indicating that significant ice must have been present in the disk at the time of carbonaceous asteroid accretion. Finally, some carbonaceous chondrite meteorites preserve amorphous iron-bearing materials

  8. Solar wind ion trends and signatures: STEREO PLASTIC observations approaching solar minimum

    Directory of Open Access Journals (Sweden)

    A. B. Galvin

    2009-10-01

    Full Text Available STEREO has now completed the first two years of its mission, moving from close proximity to Earth in 2006/2007 to more than 50 degrees longitudinal separation from Earth in 2009. During this time, several large-scale structures have been observed in situ. Given the prevailing solar minimum conditions, these structures have been predominantly coronal hole-associated solar wind, slow solar wind, their interfaces, and the occasional transient event. In this paper, we extend earlier solar wind composition studies into the current solar minimum using high-resolution (1-h sampling times for the charge state analysis. We examine 2-year trends for iron charge states and solar wind proton speeds, and present a case study of Carrington Rotation 2064 (December 2007 which includes minor ion (He, Fe, O kinetic and Fe composition parameters in comparison with proton and magnetic field signatures at large-scale structures observed during this interval.

  9. The nature of cometary dust as determined from infrared observations

    International Nuclear Information System (INIS)

    Swamy, K.S.K.; Sandford, S.A.; Allamandola, L.J.; Witteborn, F.C.; Bregman, J.D.

    1989-01-01

    The presence of 10 and 3.4 micron features in Comet Halley (c.f. Bregman et al. 1987; Wickramasinghe and Allen 1986) indicated the presence of at least two components in the grain material, namely silicates and some form of amorphous carbon. These two components could reside in separate grains or may be parts of composite particles. Both these cases have been considered (see Krishna Swamy el a. 1988a, 1988b). In the absence of refractive index data for cometary analogs, the authors used the optical constants of olivine-rich lunar material 12009.48 (Perry et al. 1972) for the infrared region and that of alpha:C-H film for amorphous carbon (angus et al. 1986). For the visible region, a value of m = 1.38-0.39i was used for the silicates, and values published by Arakawa et al. (1985) were used for the amorphous carbon. These materials should give a representative behavior of the expected results. The model results were compared to observational data. The strength of the 3.4 micron and 10 micron features relative to the adjacent continuum, as well as the slope of the continuum between 2500 and 1250 cm(exp -1) (4 to 8 microns), were used as criteria for comparison. Model calculations with alpha approx. equals -3.5, and also the size distribution function inferred for Comet Halley, with a mass fraction (X) of silicate to amorphous carbon grains of about 40 to 1 can fit the data

  10. Analysis of auroral infrared emissions observed during the ELIAS experiment

    Directory of Open Access Journals (Sweden)

    G. E. Caledonia

    Full Text Available The ELIAS (Earth Limb Infrared Atmospheric Structure experiment was flown from the Poker Flat Research Range, Alaska in 1983 and successfully monitored visible and infrared emissions from an IBC III+ aurora. Measurements were performed in both staring and scanning modes over several hundred seconds. The data for short- and mid-wave infrared regions have been analyzed in terms of auroral excitation of the NO and NO+ vibrational bands. Auroral excitation efficiencies and kinetic implications are presented.

  11. Thermal Field Analysis and Simulation of an Infrared Belt Furnace Used for Solar Cells

    Directory of Open Access Journals (Sweden)

    Bai Lu

    2014-01-01

    Full Text Available During solar cell firing, volatile organic compounds (VOC and a small number of metal particles were removed using the gas flow. When the gas flow was disturbed by the thermal field of infrared belt furnace and structure, the metal particles in the discharging gas flow randomly adhered to the surface of solar cell, possibly causing contamination. Meanwhile, the gas flow also affected the thermal uniformity of the solar cell. In this paper, the heating mechanism of the solar cell caused by radiation, convection, and conduction during firing was analyzed. Afterward, four 2-dimensional (2D models of the furnace were proposed. The transient thermal fields with different gas inlets, outlets, and internal structures were simulated. The thermal fields and the temperature of the solar cell could remain stable and uniform when the gas outlets were installed at the ends and in the middle of the furnace, with the gas inlets being distributed evenly. To verify the results, we produced four types of furnaces according to the four simulated results. The experimental results indicated that the thermal distribution of the furnace and the characteristics of the solar cells were consistent with the simulation. These experiments improved the efficiency of the solar cells while optimizing the solar cell manufacturing equipment.

  12. Infrared radiation increases skin damage induced by other wavelengths in solar urticaria.

    Science.gov (United States)

    de Gálvez, María Victoria; Aguilera, José; Sánchez-Roldán, Cristina; Herrera-Ceballos, Enrique

    2016-09-01

    Photodermatoses are typically investigated by analyzing the individual or combined effects of ultraviolet A (UVA), ultraviolet B (UVB), and visible light using light sources that simulate portions of the solar spectrum. Infrared radiation (IRR), however, accounts for 53% of incident solar radiation, but its effects are not taken into account in standard phototest protocols. The aim was to analyze the effects of IRR, alone and combined with UVA and visible light on solar urticaria lesions, with a distinction between infrared A (IRA) and infrared B (IRB). We performed standard phototests with UVA and visible light in four patients with solar urticaria and also tested the effects after blocking IRB with a water filter. To analyze the direct effect of IRR, we performed phototests with IRA and IRB. Initial standard phototests that were all positive found the induction of erythema and whealing, while when IRR was blocked from the UVA and visible light sources, three of the patients developed no lesions, while the fourth developed a very small wheal. These results suggest that IRR has the potential to produce and exacerbate lesions caused by other types of radiation. Consideration of these effects during phototesting could help prevent diagnostic errors. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Determination of variations of the solar radius from solar eclipse observations

    Science.gov (United States)

    Sofia, S.; Dunham, D. W.; Fiala, A. D.

    1980-01-01

    This paper describes the method to determine the solar radius and its variations from observations made during total solar eclipses. In particular, the procedure to correct the spherical moon predictions for the effects of lunar mountains and valleys on the width and location of the path of totality is addressed in detail. The errors affecting this technique are addressed, a summary of the results of its application to three solar eclipses are presented, and the implications of the results on the constancy of the solar constant are described.

  14. Infrared observations of the eclipsing millisecond pulsar 1957 + 20

    International Nuclear Information System (INIS)

    Eales, S.A.; Becklin, E.E.; Zuckerman, B.

    1990-01-01

    We have taken 2.2-μm images, over the entire range of orbital phase, of the eclipsing millisecond pulsar 1957 + 20. We show that the 2.2-μm flux from the pulsar system is variable, and that the infrared light curve is similar to the optical light curve. Four additional images at 1.2 μm show that there is a possible infrared excess from the system. (author)

  15. Solar variability observed through changes in solar figure and mean diameter

    International Nuclear Information System (INIS)

    Hill, H.A.

    1984-01-01

    The objective of the project is to detect and monitor climatically significant solar variability by accurate monitoring of the associated variability in solar shape and diameter. The observing program for this project was initiated in 1981. Solar diameter measurements have been taken and data reduction programs for these measurements have been developed. Theoretical analysis of the expected change in the intensity from the solar atmosphere to a given mechanial driving has progressed to the extent that changes in the solar diameter can be related to the associated change in the solar luminosity. An absolute calibration system for the telescope has been constructed and is currently being tested. A proposal is made for the continuation of the work in each of these areas

  16. Infrared observations of Comet Austin (1990 V) by the COBE/Diffuse Infrared Background Experiment

    Science.gov (United States)

    Lisse, C. M.; Freudenreich, H. T.; Hauser, M. G.; Kelsall, T.; Moseley, S. H.; Reach, W. T.; Silverberg, R. F.

    1994-01-01

    Comet Austin was observed by the Cosmic Background Explorer (COBE)/Diffuse Infrared Background Experiment (DIRBE) with broadband photometry at 1-240 micrometers during the comet's close passage by Earth in 1990 May. A 6 deg long (6 x 10(exp 6) km) dust tail was found at 12 and 25 micrometers, with detailed structure due to variations in particle properties and mass-loss rate. The spectrum of the central 42 x 42 sq arcmin pixel was found to agree with that of a graybody of temperature 309 +/- 5 K and optical depth 7.3 +/- 10(exp -8). Comparison with IUE and ground-based obervations indicates that particles of radius greater than 20 micrometers predominate by surface area. A mass-loss rate of 510 (+510/-205) kg/s and a total tail mass of 7 +/- 2 x 10(exp 10) kg was found for a model dust tail composed of Mie spheres with a differential particle mass distribution dn/d log m approx. m(exp -0.63) and 2:1 silicate:amorphous carbon composition by mass.

  17. Solar thermal barometer - EurObserv'ER - May 2016

    International Nuclear Information System (INIS)

    2016-05-01

    In 2015, the European Union saw its solar thermal market contract for the seventh year in a row. EurObserv'ER puts sales of solar thermal capacity installed for the heating market (hot water and space heating) at 1861 MWth, equivalent to a 2.7 million m"2 of collectors... a further 8.6% decrease on the previous year's poor performance. Combined solar thermal capacity installed to date in the EU stands at 34.3 GWth, or 49 million m"2 of collectors

  18. Observations of Halley's Comet by the Solar Maximum Mission (SMM)

    Science.gov (United States)

    Niedner, M. B.

    1986-01-01

    Solar Maximum Mission coronagraph/polarimeter observations of large scale phenomena in Halley's Comet are discussed. Observations of the hydrogen coma with the UV spectrometer are considered. It is concluded that coronograph/polarimeter observations of the disconnection event, in which the entire plasma tail uproots itself from the head of the comet, is convected away in the solar wind at speeds in the 50 to 100 km/sec range (relative to the head), and is replaced by a plasma tail constructed from folding ion-tail rays, are the most interesting.

  19. Mass loss rates of OB stars derived from infrared observations

    International Nuclear Information System (INIS)

    Tanzi, E.G.; Tarenghi, M.; Panagia, N.

    1981-01-01

    In this paper the authors report briefly on a study of the mass loss of early type stars in the infrared. Up to now near infrared (1.25 - 4.8 μ) broad band photometry of 70 southern OB stars of various luminosity class has been secured. Program stars have been selected, among those bright enough in the infrared to give a suitable photometric accuracy, in order to cover a wide range of spectral types. 37 stars are found to exhibit emission in excess over a blackbody photospheric continuum, which is interpreted in terms of gas ejected in the form of an accelerated wind. By means of model calculations the corresponding mass loss rates are derived. The obtained values compare well with those determined independently by various authors for stars in common. Their data show that mass loss rates increase with luminosity and are a decreasing function of surface gravity. (Auth.)

  20. Observations of gamma-ray emission in solar flares

    International Nuclear Information System (INIS)

    Forrest, D.J.; Chupp, E.L.; Suri, A.N.; Reppin, C.

    1973-01-01

    This paper reviews the observations of gamma-ray emission made from the OSO-7 satellite in connection with two solar flares in early August 1972. The details of the measurements and a preliminary interpretation of some of the observed features are given. (U.S.)

  1. Solar variability observed through changes in solar figure and mean diameter

    International Nuclear Information System (INIS)

    Hill, H.A.

    1991-01-01

    The work performed on solar variability during 1990 at SCLERA is reviewed. That portion of the SCLERA research program supported by the Department of Energy has been directed toward the detection and monitoring of climatically significant solar variability by accurate measurement of the variability in solar shape and diameter. Observations were obtained in 1990 and results from analysis of earlier observations obtained. The observational evidence of systematic long-term changes in the apparent solar diameter and/or radius has been detected, and these changes continue to strongly correlated with long-term changes in solar total irradiance. Additional evidence for internal gravity modes has been found which may be important to understanding the internal structure of the Sun. Each of these findings shows promise for anticipating future changes in the solar luminosity. Progress has been made in setting up an international network based on SCLERA-type instruments to improve the coverage and quality of the observations. A proposal is made for the continuation of support from the Department of Energy for further studies relevant to solar-variability forecasting

  2. Perylene anhydride fused porphyrins as near-infrared sensitizers for dye-sensitized solar cells

    KAUST Repository

    Jiao, Chongjun

    2011-07-15

    Two perylene anhydride fused porphyrins 1 and 2 have been synthesized and employed successfully in dye-sensitized solar cells (DSCs). Both compounds showed broad incident monochromatic photon-to-current conversion efficiency spectra covering the entire visible spectral region and even extending into the near-infrared (NIR) region up to 1000 nm, which is impressive for ruthenium-free dyes in DSCs. © 2011 American Chemical Society.

  3. Comment on "Infrared freezing of Euclidean QCD observables"

    Czech Academy of Sciences Publication Activity Database

    Caprini, I.; Fischer, Jan

    2007-01-01

    Roč. 76, č. 1 (2007), 018501/1-018501/5 ISSN 1550-7998 R&D Projects: GA MŠk 1P04LA211 Institutional research plan: CEZ:AV0Z10100502 Keywords : QCD * analyticity * infrared freezing Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 4.696, year: 2007

  4. Orion star-forming region - far-infrared and radio molecular observations

    International Nuclear Information System (INIS)

    Thronson, H.A. Jr.; Harper, D.A.; Bally, J.; Dragovan, M.; Mozurkewich, D.; Yerkes Observatory, Williams Bay, WI; ATandT Bell Labs., Holmdel, NJ; Chicago Uni., IL; E. O. Hulburt Center for Space Research, Washington, DC)

    1986-01-01

    New J = 1-0 CO and far-infrared maps of the Orion star-forming region are presented and discussed. The total infrared luminosity of the Orion star-forming ridge is 250,000 solar luminosities. The material that is emitting strongly at 60 microns is traced and found to be highly centrally concentrated. However, the majority of the extended emission from this region comes from dust that is ultimately heated by the visible Trapezium cluster stars. The luminosity of IRc 2, the most luminous member of the infrared cluster, is estimated to be 40,000-50,000 solar luminosities. A schematic drawing of the Ori MC 1 region is presented. 30 references

  5. Possible influence of cosmic ray Cerenkov photons on infrared interferometric search for non-solar planets

    International Nuclear Information System (INIS)

    Lerche, I.

    1980-01-01

    It is shown that the pervasive cosmic-ray protons in the vicinity of the Earth would produce infrared photons by Cerenkov radiation in the material walls, and mirrors, of an orbiting infrared interferometer designed to search for non-solar planets. The flux of such photons is at least comparable to the zodiacal infrared background radiation. It is found that for the worst possible conditions a minimum time of about six weeks is indicated for planetary detection using a fourth-harmonic noise analysis. It is suggested that direct laboratory measurement of a simulated cosmic-ray-induced Cerenkov flux be undertaken to settle the question of the background contaminant produced by this effect. (Auth.)

  6. The solar wind at solar maximum: comparisons of EISCAT IPS and in situ observations

    Directory of Open Access Journals (Sweden)

    A. R. Breen

    Full Text Available The solar maximum solar wind is highly structured in latitude, longitude and in time. Coronal measurements show a very high degree of variability, with large variations that are less apparent within in situ spacecraft measurements. Interplanetary scintillation (IPS observations from EISCAT, covering distances from 20 to 100 solar radii (RS, are an ideal source of information on the inner solar wind and can be used, therefore, to cast light on its evolution with distance from the Sun. Earlier comparisons of in situ and IPS measurements under solar minimum conditions showed good large-scale agreement, particularly in the fast wind. In this study we attempt a quantitative comparison of measurements made over solar maximum by EISCAT (20–100 RS and the Wind and Ulysses spacecraft (at 215 RS and 300–1000 RS, respectively. The intervals studied were August–September 1999, May 2000, September 2000 and May 2001, the last-named being the period of the second Ulysses fast latitude scan. Both ballistic and – when possible – MHD/ballistic hybrid models were used to relate the data sets, and we compare the results obtained from these two mapping methods. The results of this study suggest that solar wind velocities measured in situ were less variable than those estimated from IPS measurements closer to the Sun, with the greatest divergence between IPS velocities and in situ measurements occurring in regions where steep longitudinal velocity gradients were seen in situ. We suggest that the interaction between streams of solar wind with different velocities leads to "smoothing" of solar wind velocities between 30–60 RS and 1 AU, and that this process continues at greater distances from the Sun.

    Key words. Interplanetary physics (solar wind plasma; sources of the solar wind; instruments and techniques

  7. Observational capabilities of solar satellite "Coronas-Photon"

    Science.gov (United States)

    Kotov, Yu.

    Coronas-Photon mission is the third satellite of the Russian Coronas program on solar activity observation The main goal of the Coronas-Photon is the study of solar hard electromagnetic radiation in the wide energy range from UV up to high energy gamma-radiation sim 2000MeV Scientific payload for solar radiation observation consists of three type of instruments 1 monitors Natalya-2M Konus-RF RT-2 Penguin-M BRM Phoka Sphin-X Sokol for spectral and timing measurements of full solar disk radiation with timing in flare burst mode up to one msec Instruments Natalya-2M Konus-RF RT-2 will cover the wide energy range of hard X-rays and soft Gamma rays 15keV to 2000MeV and will together constitute the largest area detectors ever used for solar observations Detectors of gamma-ray monitors are based on structured inorganic scintillators with energy resolution sim 5 for nuclear gamma-line band to 35 for GeV-band PSD analysis is used for gamma neutron separation for solar neutron registration T 30MeV Penguin-M has capability to measure linear polarization of hard X-rays using azimuth are measured by Compton scattering asymmetry in case of polarization of an incident flux For X-ray and EUV monitors the scintillation phoswich detectors gas proportional counter CZT assembly and Filter-covered Si-diodes are used 2 Telescope-spectrometer TESIS for imaging solar spectroscopy in X-rays with angular resolution up to 1 in three spectral lines and RT-2 CZT assembly of CZT

  8. Observational Evidence of Magnetic Waves in the Solar Atmosphere

    Science.gov (United States)

    McIntosh, Scott W.

    2012-03-01

    The observational evidence in supporting the presence of magnetic waves in the outer solar atmosphere is growing rapidly - we will discuss recent observations and place them in context with salient observations made in the past. While the clear delineation of these magnetic wave "modes" is unclear, much can be learned about the environment in which they originated and possibly how they are removed from the system from the observations. Their diagnostic power is, as yet, untapped and their energy content (both as a mechanical source for the heating of coronal material and acceleration of the solar wind) remains in question, but can be probed observationally - raising challenges for modeling efforts. We look forward to the IRIS mission by proposing some sample observing sequences to help resolve some of the zoological issues present in the literature.

  9. The effect of clouds on the earth's solar and infrared radiation budgets

    Science.gov (United States)

    Herman, G. F.; Wu, M.-L. C.; Johnson, W. T.

    1980-01-01

    The effect of global cloudiness on the solar and infrared components of the earth's radiation balance is studied in general circulation model experiments. A wintertime simulation is conducted in which the cloud radiative transfer calculations use realistic cloud optical properties and are fully interactive with model-generated cloudiness. This simulation is compared to others in which the clouds are alternatively non-interactive with respect to the solar or thermal radiation calculations. Other cloud processes (formation, latent heat release, precipitation, vertical mixing) were accurately simulated in these experiments. It is concluded that on a global basis clouds increase the global radiation balance by 40 W/sq m by absorbing longwave radiation, but decrease it by 56 W/sq m by reflecting solar radiation to space. The net cloud effect is therefore a reduction of the radiation balance by 16 W/sq m, and is dominated by the cloud albedo effect. Changes in cloud frequency and distribution and in atmospheric and land temperatures are also reported for the control and for the non-interactive simulations. In general, removal of the clouds' infrared absorption cools the atmosphere and causes additional cloudiness to occur, while removal of the clouds' solar radiative properties warms the atmosphere and causes fewer clouds to form. It is suggested that layered clouds and convective clouds over water enter the climate system as positive feedback components, while convective clouds over land enter as negative components.

  10. SPITZER OBSERVATIONS OF PASSIVE AND STAR-FORMING EARLY-TYPE GALAXIES: AN INFRARED COLOR-COLOR SEQUENCE

    International Nuclear Information System (INIS)

    Temi, Pasquale; Brighenti, Fabrizio; Mathews, William G.

    2009-01-01

    We describe the infrared properties of a large sample of early-type galaxies, comparing data from the Spitzer archive with Ks-band emission from the Two Micron All Sky Survey. While most representations of this data result in correlations with large scatter, we find a remarkably tight relation among colors formed by ratios of luminosities in Spitzer-Multiband Imaging Photometer bands (24, 70, and 160 μm) and the Ks band. Remarkably, this correlation among E and S0 galaxies follows that of nearby normal galaxies of all morphological types. In particular, the tight infrared color-color correlation for S0 galaxies alone follows that of the entire Hubble sequence of normal galaxies, roughly in order of galaxy type from ellipticals to spirals to irregulars. The specific star formation rate (SFR) of S0 galaxies estimated from the 24 μm luminosity increases with decreasing K-band luminosity (or stellar mass) from essentially zero, as with most massive ellipticals, to rates typical of irregular galaxies. Moreover, the luminosities of the many infrared-luminous S0 galaxies can significantly exceed those of the most luminous (presumably post-merger) E galaxies. SFRs in the most infrared-luminous S0 galaxies approach 1-10 solar masses per year. Consistently, with this picture we find that while most early-type galaxies populate an infrared red sequence, about 24% of the objects (mostly S0s) are in an infrared blue cloud together with late-type galaxies. For those early-type galaxies also observed at radio frequencies, we find that the far-infrared luminosities correlate with the mass of neutral and molecular hydrogen, but the scatter is large. This scatter suggests that the star formation may be intermittent or that similar S0 galaxies with cold gaseous disks of nearly equal mass can have varying radial column density distributions that alter the local and global SFRs.

  11. Physics of the Solar Active Regions from Radio Observations

    Science.gov (United States)

    Gelfreikh, G. B.

    1999-12-01

    Localized increase of the magnetic field observed by routine methods on the photosphere result in the growth of a number of active processes in the solar atmosphere and the heliosphere. These localized regions of increased magnetic field are called active regions (AR). The main processes of transfer, accumulation and release of energy in an AR is, however, out of scope of photospheric observations being essentially a 3D-process and happening either under photosphere or up in the corona. So, to investigate these plasma structures and processes we are bound to use either extrapolation of optical observational methods or observations in EUV, X-rays and radio. In this review, we stress and illustrate the input to the problem gained from radio astronomical methods and discuss possible future development of their applicatications. Historically speaking each new step in developing radio technique of observations resulted in detecting some new physics of ARs. The most significant progress in the last few years in radio diagnostics of the plasma structures of magnetospheres of the solar ARs is connected with the developing of the 2D full disk analysis on regular basis made at Nobeyama and detailed multichannel spectral-polarization (but one-dimensional and one per day) solar observations at the RATAN-600. In this report the bulk of attention is paid to the new approach to the study of solar activity gained with the Nobeyama radioheliograph and analyzing the ways for future progress. The most important new features of the multicomponent radio sources of the ARs studied using Nobeyama radioheliograph are as follow: 1. The analysis of magnetic field structures in solar corona above sunspot with 2000 G. Their temporal evolution and fluctuations with the periods around 3 and 5 minutes, due to MHD-waves in sunspot magnetic tubes and surrounding plasma. These investigations are certainly based on an analysis of thermal cyclotron emission of lower corona and CCTR above sunspot

  12. Diamagnetic effect in the foremoon solar wind observed by Kaguya

    Science.gov (United States)

    Nishino, Masaki N.; Saito, Yoshifumi; Tsunakawa, Hideo; Miyake, Yohei; Harada, Yuki; Yokota, Shoichiro; Takahashi, Futoshi; Matsushima, Masaki; Shibuya, Hidetoshi; Shimizu, Hisayoshi

    2017-04-01

    Direct interaction between the lunar surface and incident solar wind is one of the crucial phenomena of the planetary plasma sciences. Recent observations by lunar orbiters revealed that strength of the interplanetary magnetic field (IMF) at spacecraft altitude often increases over crustal magnetic fields on the dayside. In addition, variations of the IMF on the lunar night side have been reported in the viewpoint of diamagnetic effect around the lunar wake. However, few studies have been performed for the IMF over non-magnetized regions on the dayside. Here we show an event where strength of the IMF decreases at 100 km altitude on the lunar dayside (i.e. in the foremoon solar wind) when the IMF is almost parallel to the incident solar wind flow, comparing the upstream solar wind data from ACE with Kaguya magnetometer data. The lunar surface below the Kaguya orbit is not magnetized (or very weakly magnetized), and the sunward-travelling protons show signatures of those back-scattered at the lunar surface. We find that the decrease in the magnetic pressure is compensated by the thermal pressure of the back-scattered protons. In other words, the IMF strength in the foremoon solar wind decreases by diamagnetic effect of sunward-travelling protons back-scattered at the lunar dayside surface. Such an effect would be prominent in the high-beta solar wind, and may be ubiquitous in the environment where planetary surface directly interacts with surrounding space plasma.

  13. Piecewise mass flows within a solar prominence observed by the New Vacuum Solar Telescope

    Science.gov (United States)

    Li, Hongbo; Liu, Yu; Tam, Kuan Vai; Zhao, Mingyu; Zhang, Xuefei

    2018-06-01

    The material of solar prominences is often observed in a state of flowing. These mass flows (MF) are important and useful for us to understand the internal structure and dynamics of prominences. In this paper, we present a high resolution Hα observation of MFs within a quiescent solar prominence. From the observation, we find that the plasma primarily has a circular motion and a downward motion separately in the middle section and legs of the prominence, which creates a piecewise mass flow along the observed prominence. Moreover, the observation also shows a clear displacement of MF's velocity peaks in the middle section of the prominence. All of these provide us with a detailed record of MFs within a solar prominence and show a new approach to detecting the physical properties of prominence.

  14. HIGH SPATIAL RESOLUTION OBSERVATIONS OF LOOPS IN THE SOLAR CORONA

    Energy Technology Data Exchange (ETDEWEB)

    Brooks, David H.; Ugarte-Urra, Ignacio [College of Science, George Mason University, 4400 University Drive, Fairfax, VA 22030 (United States); Warren, Harry P. [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States); Winebarger, Amy R. [NASA Marshall Space Flight Center, ZP 13, Huntsville, AL 35812 (United States)

    2013-08-01

    Understanding how the solar corona is structured is of fundamental importance to determine how the Sun's upper atmosphere is heated to high temperatures. Recent spectroscopic studies have suggested that an instrument with a spatial resolution of 200 km or better is necessary to resolve coronal loops. The High Resolution Coronal Imager (Hi-C) achieved this performance on a rocket flight in 2012 July. We use Hi-C data to measure the Gaussian widths of 91 loops observed in the solar corona and find a distribution that peaks at about 270 km. We also use Atmospheric Imaging Assembly data for a subset of these loops and find temperature distributions that are generally very narrow. These observations provide further evidence that loops in the solar corona are often structured at a scale of several hundred kilometers, well above the spatial scale of many proposed physical mechanisms.

  15. Applying Nyquist's method for stability determination to solar wind observations

    Science.gov (United States)

    Klein, Kristopher G.; Kasper, Justin C.; Korreck, K. E.; Stevens, Michael L.

    2017-10-01

    The role instabilities play in governing the evolution of solar and astrophysical plasmas is a matter of considerable scientific interest. The large number of sources of free energy accessible to such nearly collisionless plasmas makes general modeling of unstable behavior, accounting for the temperatures, densities, anisotropies, and relative drifts of a large number of populations, analytically difficult. We therefore seek a general method of stability determination that may be automated for future analysis of solar wind observations. This work describes an efficient application of the Nyquist instability method to the Vlasov dispersion relation appropriate for hot, collisionless, magnetized plasmas, including the solar wind. The algorithm recovers the familiar proton temperature anisotropy instabilities, as well as instabilities that had been previously identified using fits extracted from in situ observations in Gary et al. (2016). Future proposed applications of this method are discussed.

  16. High resolution solar observations from first principles to applications

    Science.gov (United States)

    Verdoni, Angelo P.

    2009-10-01

    The expression "high-resolution observations" in Solar Physics refers to the spatial, temporal and spectral domains in their entirety. High-resolution observations of solar fine structure are a necessity to answer many of the intriguing questions related to solar activity. However, a researcher building instruments for high-resolution observations has to cope with the fact that these three domains often have diametrically opposed boundary conditions. Many factors have to be considered in the design of a successful instrument. Modern post-focus instruments are more closely linked with the solar telescopes that they serve than in past. In principle, the quest for high-resolution observations already starts with the selection of the observatory site. The site survey of the Advanced Technology Solar Telescope (ATST) under the stewardship of the National Solar Observatory (NSO) has identified Big Bear Solar Observatory (BBSO) as one of the best sites for solar observations. In a first step, the seeing characteristics at BBSO based on the data collected for the ATST site survey are described. The analysis will aid in the scheduling of high-resolution observations at BBSO as well as provide useful information concerning the design and implementation of a thermal control system for the New Solar Telescope (NST). NST is an off-axis open-structure Gregorian-style telescope with a 1.6 m aperture. NST will be housed in a newly constructed 5/8-sphere ventilated dome. With optics exposed to the surrounding air, NST's open-structure design makes it particularly vulnerable to the effects of enclosure-related seeing. In an effort to mitigate these effects, the initial design of a thermal control system for the NST dome is presented. The goal is to remediate thermal related seeing effects present within the dome interior. The THermal Control System (THCS) is an essential component for the open-telescope design of NST to work. Following these tasks, a calibration routine for the

  17. INFRARED OBSERVATIONAL MANIFESTATIONS OF YOUNG DUSTY SUPER STAR CLUSTERS

    Energy Technology Data Exchange (ETDEWEB)

    Martínez-González, Sergio; Tenorio-Tagle, Guillermo; Silich, Sergiy, E-mail: sergiomtz@inaoep.mx [Instituto Nacional de Astrofísica Óptica y Electrónica, AP 51, 72000 Puebla (Mexico)

    2016-01-01

    The growing evidence pointing at core-collapse supernovae as large dust producers makes young massive stellar clusters ideal laboratories to study the evolution of dust immersed in a hot plasma. Here we address the stochastic injection of dust by supernovae, and follow its evolution due to thermal sputtering within the hot and dense plasma generated by young stellar clusters. Under these considerations, dust grains are heated by means of random collisions with gas particles which result in the appearance of  infrared spectral signatures. We present time-dependent infrared spectral energy distributions that are to be expected from young stellar clusters. Our results are based on hydrodynamic calculations that account for the stochastic injection of dust by supernovae. These also consider gas and dust radiative cooling, stochastic dust temperature fluctuations, the exit of dust grains out of the cluster volume due to the cluster wind, and a time-dependent grain size distribution.

  18. INFRARED OBSERVATIONAL MANIFESTATIONS OF YOUNG DUSTY SUPER STAR CLUSTERS

    International Nuclear Information System (INIS)

    Martínez-González, Sergio; Tenorio-Tagle, Guillermo; Silich, Sergiy

    2016-01-01

    The growing evidence pointing at core-collapse supernovae as large dust producers makes young massive stellar clusters ideal laboratories to study the evolution of dust immersed in a hot plasma. Here we address the stochastic injection of dust by supernovae, and follow its evolution due to thermal sputtering within the hot and dense plasma generated by young stellar clusters. Under these considerations, dust grains are heated by means of random collisions with gas particles which result in the appearance of  infrared spectral signatures. We present time-dependent infrared spectral energy distributions that are to be expected from young stellar clusters. Our results are based on hydrodynamic calculations that account for the stochastic injection of dust by supernovae. These also consider gas and dust radiative cooling, stochastic dust temperature fluctuations, the exit of dust grains out of the cluster volume due to the cluster wind, and a time-dependent grain size distribution

  19. COBE diffuse infrared background experiment observations of the galactic bulge

    Science.gov (United States)

    Weiland, J. L.; Arendt, R. G.; Berriman, G. B.; Dwek, E.; Freudenreich, H. T.; Hauser, M. G.; Kelsall, T.; Lisse, C. M.; Mitra, M.; Moseley, S. H.

    1994-01-01

    Low angular resolution maps of the Galactic bulge at 1.25, 2.2, 3.5, and 4.9 micrometers obtained by the Diffuse Infrared Background Experiment (DIRBE) onboard NASA's Cosmic Background Explorer (COBE) are presented. After correction for extinction and subtraction of an empirical model for the Galactic disk, the surface brightness distribution of the bulge resembles a flattened ellipse with a minor-to-major axis ratio of approximately 0.6. The bulge minor axis scale height is found to be 2.1 deg +/- 0.2 deg for all four near-infrared wavelengths. Asymmetries in the longitudinal distribution of bulge brightness contours are qualitatively consistent with those expected for a triaxial bar with its near end in the first Galactic quadrant (0 deg less than l less than 90 deg). There is no evidence for an out-of-plane tilt of such a bar.

  20. Solar thermal and concentrated solar power barometer - EurObserv'ER - May 2012

    International Nuclear Information System (INIS)

    2012-05-01

    27545 MWth: the EU's solar thermal base to date at the end of 2011. After two years of sharp decline, the European solar thermal market is bottoming out. The EurObserv'ER survey findings are that the installation figure fell just 1.9% in comparison with 2010, giving a newly-installed collector area of 3.7 million m 2 . The concentrated solar power sector has been forging ahead alongside the heat production applications, and at the end of 2011 installed capacity passed the one gigawatt mark in Spain for the first time with 1157.2 MWe

  1. The Solar Wind from Pseudostreamers and their Environs: Opportunities for Observations with Parker Solar Probe and Solar Orbiter

    Science.gov (United States)

    Panasenco, O.; Velli, M.; Panasenco, A.; Lionello, R.

    2017-12-01

    The solar dynamo and photospheric convection lead to three main types of structures extending from the solar surface into the corona - active regions, solar filaments (prominences when observed at the limb) and coronal holes. These structures exist over a wide range of scales, and are interlinked with each other in evolution and dynamics. Active regions can form clusters of magnetic activity and the strongest overlie sunspots. In the decay of active regions, the boundaries separating opposite magnetic polarities (neutral lines) develop specific structures called filament channels above which filaments form. In the presence of flux imbalance decaying active regions can also give birth to lower latitude coronal holes. The accumulation of magnetic flux at coronal hole boundaries also creates conditions for filament formation: polar crown filaments are permanently present at the boundaries of the polar coronal holes. Mid-latitude and equatorial coronal holes - the result of active region evolution - can create pseudostreamers if other coronal holes of the same polarity are present. While helmet streamers form between open fields of opposite polarities, the pseudostreamer, characterized by a smaller coronal imprint, typically shows a more prominent straight ray or stalk extending from the corona. The pseudostreamer base at photospheric heights is multipolar; often one observes tripolar magnetic configurations with two neutral lines - where filaments can form - separating the coronal holes. Here we discuss the specific role of filament channels on pseudostreamer topology and on solar wind properties. 1D numerical analysis of pseudostreamers shows that the properties of the solar wind from around PSs depend on the presence/absence of filament channels, number of channels and chirality at thepseudostreamer base low in the corona. We review and model possible coronal magnetic configurations and solar wind plasma properties at different distances from the solar surface that

  2. Common SphinX and RHESSI observations of solar flares

    Science.gov (United States)

    Mrozek, T.; Gburek, S.; Siarkowski, M.; Sylwester, B.; Sylwester, J.; Gryciuk, M.

    The Polish X-ray spectrofotometer SphinX has observed a great number of solar flares in the year 2009 - during the most quiet solar minimum almost over the last 100 years. Hundreds of flares have been recorded due to excellent sensitivity of SphinX's detectors. The Si-PIN diodes are about 100 times more sensitive to X-rays than GOES X-ray Monitors. SphinX detectors were absolutely calibrated on Earth with a use of the BESSY synchrotron. In space observations were made in the range 1.2-15~keV with 480~eV energy resolution. SphinX data overlap with the low-energy end of the Ramaty High Energy Solar Spectroscopic Imager (RHESSI) data. RHESSI detectors are quite old (7 years in 2009), but still sensitive enough to provide us with observations of extremely weak solar flares such as those which occurred in 2009. We have selected a group of flares simultaneously observed by RHESSI and SphinX and performed a spectroscopic analysis of the data. Moreover, we compared the physical parameters of these flares plasma. Preliminary results of the comparison show very good agreement between both instruments.

  3. Signals for invisible matter from solar-terrestrial observations

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    We observe a strong correlation between the orbital position of the planets with solar phenomena like flares or the variation of EUV irradiance. Similarly, a correlation is found in the study of the ionization content of the Earth atmosphere. Planetary gravitational lensing of one (or more) streams of slow moving invisible matter is proposed as an explanation of such a behaviour.

  4. Observationally Testing the Triple Origin of Blue Straggler Stars with Near-Infrared Spectroscopy

    Science.gov (United States)

    Kohler, Jacob P.; Gosnell, Natalie M.; Sokal, Kimberly R.; Mace, Gregory N.

    2018-01-01

    Presented are results to constrain blue straggler star (BSS) formation mechanisms in open cluster NGC 188 using data from the Immersion Grating INfrared Spectrometer (IGRINS) while at the Discovery Channel Telescope. The majority (at least 16 of 21) of NGC 188s BSSs are binaries, and, to date, seven white dwarf (WD) companions have been detected. This leaves at least nine undetected companion stars. Observations show a sharp peak of the BSSs companion mass distribution at 0.5 solar masses, highly suggestive of a WD or M-type main sequence (MS) star. Under our tested formation mechanism, the progenitors of BSSs are arranged in primordial hierarchical triple star systems that dynamically evolve through the Kozai-cycle tidal friction (KCTF) process into a binary composed of a BSS and, statistically, an M dwarf companion. We test for the presence of an M dwarf by cross-correlating a near-IR spectrum with both a BSS template and an M dwarf template. We present, for the first time, a preliminary detection of a 3800K, 0.5 solar mass M dwarf companion in each of the long period (log[P(d)]=3), single-lined binaries WOCS 451 and WOCS 5671 in NGC 188. To assess the possibility of a false M dwarf detection, we carry out Monte Carlo simulations cross-correlating an M dwarf template with a BSS-only spectrum with a signal-to-noise ratio matching our observations. Theoretical detection limits for various BSS-M dwarf pairs are reported. In the case of a non-detection, such as in WOCS 4970, we are able to place an upper limit on the mass, and thus temperature, of the companion star. Current and future research goals aim for further insight into the BSS formation mechanism frequencies of NGC 188.

  5. Characteristics of solar and heliospheric ion populations observed near earth

    International Nuclear Information System (INIS)

    Gloeckler, G.

    1984-01-01

    The composition and spectra of ions in solar-energetic-particle and energetic-storm-particle events, of diffuse ions upstream of the earth bow shock, and of ions in deep-geomagnetic-tail plasmoids are characterized in a summary of in situ observations. Data are presented in graphs and tables, and remarkable similarities are noted in the distribution functions of the heliospheric ion populations. The solar wind, acting through acceleration mechanisms associated with shocks and turbulence, is identified as the major plasma source of suprathermal and energetic particles. 33 references

  6. Solar radio observations in support of Skylab A

    Science.gov (United States)

    Gotwols, B. L.

    1974-01-01

    The solar radio spectra were recorded in real time, both on film and magnetic tape, during the period from November 1972 to February 1974. A catalogue of the observations is given for the frequency range 565-1000 MHz and includes descriptions of the bursts, intensity scales, and pertinent remarks. Some theoretical considerations resulting from the research are given. Equipment modified for the experiment is described and the text of the final report which summarizes the research on type IV solar radio bursts is included.

  7. Steady flows in the solar transition region observed with SMM

    International Nuclear Information System (INIS)

    Gebbie, K.B.; Hill, F.; Toomre, J.; November, L.J.; Simon, G.W.; Gurman, J.B.; Shine, R.A.; Woodgate, B.E.; Athay, R.G.; Bruner, E.C. Jr.; Rehse, R.A.; Tandberg-Hanssen, E.A.

    1981-01-01

    Steady flows in the quiet solar transition region have been observed with the Ultraviolet Spectrometer and Polarimeter (UVSP) experiment on the Solar Maximum Mission (SMM) satellite. The persistent vertical motions seen at disk center have spatial rms amplitudes of 1.4 km s -1 in the C II line, 3.9 km s -1 in Si IV, and 4.2 km s -1 in C IV. The amplitudes of the more horizontal flows seen toward the limb tend to be somewhat higher. Plots of steady vertical velocity versus intensity seen at disk center in Si IV and C IV show two distinct branches

  8. Density gradients in the solar plasma observed by interplanetary scintillation

    International Nuclear Information System (INIS)

    Gapper, G.R.; Hewish, A.

    1981-01-01

    A new technique is described which overcomes the limitation set by Fresnel filtering in previous IPS studies of the small-scale density irregularities in the solar plasma. Phase gradients introduced by irregularities larger than the Fresnel limit cause transverse displacements of the small-scale scintillation pattern. In the presence of the solar wind, such refraction effects may be revealed by simultaneous measurements of intensity scintillation at two radio frequencies. Observations show that the structure corresponding to temporal frequencies approximately 0.02 Hz is in agreement with an extrapolation of the Kolmogorov spectrum derived from spacecraft data at lower frequencies. (author)

  9. Initial solar observations with Prototype Brazilian Decimetric Array

    Science.gov (United States)

    Fernandes, F. C. R.; Ramesh, R.; Cecatto, J. R.; Faria, C.; Andrade, M. C.; Subramanian, K. R.; Rajan, M. S. Sundara; Sawant, H. S.

    The Prototype Brazilian Decimetre Array (PBDA) consists of 5 element alt-azimuth mounted parabolic dishes of 4-m diameter, having baselines up to 216 m in East-West direction. We present initial solar observations carried out with the PBDA during the period 22nd November to 11th December, 2004. The frequency of observation was 1.6 GHz. The temporal and spatial resolution were 100 ms and 3 arcmin, respectively.

  10. Ulysses solar wind plasma observations at high southerly latitudes.

    Science.gov (United States)

    Phillips, J L; Bame, S J; Feldman, W C; Gosling, J T; Hammond, C M; McComas, D J; Goldstein, B E; Neugebauer, M; Scime, E E; Suess, S T

    1995-05-19

    Solar wind plasma observations made by the Ulysses spacecraft through -80.2 degrees solar latitude and continuing equatorward to -40.1 degrees are summarized. Recurrent high-speed streams and corotating interaction regions dominated at middle latitudes. The speed of the solar wind was typically 700 to 800 kilometers per second poleward of -35 degrees . Corotating reverse shocks persisted farther south than did forward shocks because of the tilt of the heliomagnetic streamer belt. Sporadic coronal mass ejections were seen as far south as -60.5 degrees . Proton temperature was higher and the electron strahl was broader at higher latitudes. The high-latitude wind contained compressional, pressure-balanced, and Alfvénic structures.

  11. Improving magnetosphere in situ observations using solar sails

    Science.gov (United States)

    Parsay, Khashayar; Schaub, Hanspeter; Schiff, Conrad; Williams, Trevor

    2018-01-01

    Past and current magnetosphere missions employ conventional spacecraft formations for in situ observations of the geomagnetic tail. Conventional spacecraft flying in inertially fixed Keplerian orbits are only aligned with the geomagnetic tail once per year, since the geomagnetic tail is always aligned with the Earth-Sun line, and therefore, rotates annually. Solar sails are able to artificially create sun-synchronous orbits such that the orbit apse line remains aligned with the geomagnetic tail line throughout the entire year. This continuous presence in the geomagnetic tail can significantly increase the science phase for magnetosphere missions. In this paper, the problem of solar sail formation design is explored using nonlinear programming to design optimal two-craft, triangle, and tetrahedron solar sail formations, in terms of formation quality and formation stability. The designed formations are directly compared to the formations used in NASA's Magnetospheric Multi-Scale mission.

  12. Compositionally Graded Absorber for Efficient and Stable Near-Infrared-Transparent Perovskite Solar Cells.

    Science.gov (United States)

    Fu, Fan; Pisoni, Stefano; Weiss, Thomas P; Feurer, Thomas; Wäckerlin, Aneliia; Fuchs, Peter; Nishiwaki, Shiro; Zortea, Lukas; Tiwari, Ayodhya N; Buecheler, Stephan

    2018-03-01

    Compositional grading has been widely exploited in highly efficient Cu(In,Ga)Se 2 , CdTe, GaAs, quantum dot solar cells, and this strategy has the potential to improve the performance of emerging perovskite solar cells. However, realizing and maintaining compositionally graded perovskite absorber from solution processing is challenging. Moreover, the operational stability of graded perovskite solar cells under long-term heat/light soaking has not been demonstrated. In this study, a facile partial ion-exchange approach is reported to achieve compositionally graded perovskite absorber layers. Incorporating compositional grading improves charge collection and suppresses interface recombination, enabling to fabricate near-infrared-transparent perovskite solar cells with power conversion efficiency of 16.8% in substrate configuration, and demonstrate 22.7% tandem efficiency with 3.3% absolute gain when mechanically stacked on a Cu(In,Ga)Se 2 bottom cell. Non-encapsulated graded perovskite device retains over 93% of its initial efficiency after 1000 h operation at maximum power point at 60 °C under equivalent 1 sun illumination. The results open an avenue in exploring partial ion-exchange to design graded perovskite solar cells with improved efficiency and stability.

  13. New infrared observations of IRS 1, IRS 3, and the adjacent nebula in the OMC-2 cluster

    International Nuclear Information System (INIS)

    Pendelton, Y.; Werner, M.; Dinerstein, H.

    1984-01-01

    Recent reports show that near infrared reflection nebulae are often observed around embedded protostellar objects. New observations are here reported of the infrared cluster of low luminosity protostars in Orion Molecular Cloud 2 (OMC2). It has been determined that the asymmetric distribution of the extended emission seen about IRS1 is in fact another infrared reflection nebula. Observations of near infrared polarimetry, photometry, and spectrophotometry were carried out at the NASA Infrared Telescope Facility October 1982 and January 1983. (author)

  14. WIND observations of coherent electrostatic waves in the solar wind

    Directory of Open Access Journals (Sweden)

    A. Mangeney

    1999-03-01

    Full Text Available The time domain sampler (TDS experiment on WIND measures electric and magnetic wave forms with a sampling rate which reaches 120 000 points per second. We analyse here observations made in the solar wind near the Lagrange point L1. In the range of frequencies above the proton plasma frequency fpi and smaller than or of the order of the electron plasma frequency fpe, TDS observed three kinds of electrostatic (e.s. waves: coherent wave packets of Langmuir waves with frequencies f ~ fpe, coherent wave packets with frequencies in the ion acoustic range fpi < f < fpe, and more or less isolated non-sinusoidal spikes lasting less than 1 ms. We confirm that the observed frequency of the low frequency (LF ion acoustic wave packets is dominated by the Doppler effect: the wavelengths are short, 10 to 50 electron Debye lengths λD. The electric field in the isolated electrostatic structures (IES and in the LF wave packets is more or less aligned with the solar wind magnetic field. Across the IES, which have a spatial width of the order of ~ 25λD, there is a small but finite electric potential drop, implying an average electric field generally directed away from the Sun. The IES wave forms, which have not been previously reported in the solar wind, are similar, although with a smaller amplitude, to the weak double layers observed in the auroral regions, and to the electrostatic solitary waves observed in other regions in the magnetosphere. We have also studied the solar wind conditions which favour the occurrence of the three kinds of waves: all these e.s. waves are observed more or less continuously in the whole solar wind (except in the densest regions where a parasite prevents the TDS observations. The type (wave packet or IES of the observed LF waves is mainly determined by the proton temperature and by the direction of the magnetic field, which themselves depend on the latitude of WIND with respect to the heliospheric current sheet.Key words

  15. WIND observations of coherent electrostatic waves in the solar wind

    Directory of Open Access Journals (Sweden)

    A. Mangeney

    Full Text Available The time domain sampler (TDS experiment on WIND measures electric and magnetic wave forms with a sampling rate which reaches 120 000 points per second. We analyse here observations made in the solar wind near the Lagrange point L1. In the range of frequencies above the proton plasma frequency fpi and smaller than or of the order of the electron plasma frequency fpe, TDS observed three kinds of electrostatic (e.s. waves: coherent wave packets of Langmuir waves with frequencies f ~ fpe, coherent wave packets with frequencies in the ion acoustic range fpi < f < fpe, and more or less isolated non-sinusoidal spikes lasting less than 1 ms. We confirm that the observed frequency of the low frequency (LF ion acoustic wave packets is dominated by the Doppler effect: the wavelengths are short, 10 to 50 electron Debye lengths λD. The electric field in the isolated electrostatic structures (IES and in the LF wave packets is more or less aligned with the solar wind magnetic field. Across the IES, which have a spatial width of the order of ~ 25λD, there is a small but finite electric potential drop, implying an average electric field generally directed away from the Sun. The IES wave forms, which have not been previously reported in the solar wind, are similar, although with a smaller amplitude, to the weak double layers observed in the auroral regions, and to the electrostatic solitary waves observed in other regions in the magnetosphere. We have also studied the solar wind conditions which favour the occurrence of the three kinds of waves: all these e.s. waves are observed more or less continuously in the whole solar wind (except in the densest regions where a parasite prevents the TDS observations. The type (wave packet or IES of the observed LF waves is mainly determined

  16. Solar variability observed through changes in solar figure and mean diameter

    International Nuclear Information System (INIS)

    Hill, H.A.; Bos, R.J.

    1982-01-01

    The objective of the project is to detect and monitor climatically significant solar variability by studying the associated variability in solar shape and diameter. The observing program for this project was initiated in 1981, as was the requisite data reduction. These two activities are conducted simultaneously. Theoretical work has also progressed on matters relevant to the interpretation of observed changes in the indirect diagnostics in terms of changes in the solar luminosity. The success of the observing program over long time periods depends in part on the development of a technique to calibrate the scale in the telescope field, and work on this has progressed to the design and construction phase. A proposal is made for the continuation of the work in each of these areas

  17. Effects of varying environmental conditions on emissivity spectra of bulk lunar soils: Application to Diviner thermal infrared observations of the Moon

    Science.gov (United States)

    Donaldson Hanna, K. L.; Greenhagen, B. T.; Patterson, W. R.; Pieters, C. M.; Mustard, J. F.; Bowles, N. E.; Paige, D. A.; Glotch, T. D.; Thompson, C.

    2017-02-01

    Currently, few thermal infrared measurements exist of fine particulate (samples (e.g. minerals, mineral mixtures, rocks, meteorites, and lunar soils) measured under simulated lunar conditions. Such measurements are fundamental for interpreting thermal infrared (TIR) observations by the Diviner Lunar Radiometer Experiment (Diviner) onboard NASA's Lunar Reconnaissance Orbiter as well as future TIR observations of the Moon and other airless bodies. In this work, we present thermal infrared emissivity measurements of a suite of well-characterized Apollo lunar soils and a fine particulate (sample as we systematically vary parameters that control the near-surface environment in our vacuum chamber (atmospheric pressure, incident solar-like radiation, and sample cup temperature). The atmospheric pressure is varied between ambient (1000 mbar) and vacuum (radiation is varied between 52 and 146 mW/cm2, and the sample cup temperature is varied between 325 and 405 K. Spectral changes are characterized as each parameter is varied, which highlight the sensitivity of thermal infrared emissivity spectra to the atmospheric pressure and the incident solar-like radiation. Finally spectral measurements of Apollo 15 and 16 bulk lunar soils are compared with Diviner thermal infrared observations of the Apollo 15 and 16 sampling sites. This comparison allows us to constrain the temperature and pressure conditions that best simulate the near-surface environment of the Moon for future laboratory measurements and to better interpret lunar surface compositions as observed by Diviner.

  18. Observations of Warm Water in Young Solar-System Analogs

    DEFF Research Database (Denmark)

    Persson, Magnus Vilhelm

    dioxide). The amount of warm water is deduced and its origin is observationally constrained. With both isotopologues observed, the HDO/H2O ratio is deduced. This ratio is then compared to other sources, e.g., comets and the Earth’s ocean, to gain understanding of the origin of the water in our own solar...... system. The emission line fluxes are modeled with radiative transfer tools and compared to other results of water abundances in the same source. The observed water emission, both H18(2 O and HDO is compact for all observed sources and traces the emission on R 150 AU scales or less. In one source...

  19. Particle acceleration in solar flares: observations versus numerical simulations

    International Nuclear Information System (INIS)

    Benz, A O; Grigis, P C; Battaglia, M

    2006-01-01

    Solar flares are generally agreed to be impulsive releases of magnetic energy. Reconnection in dilute plasma is the suggested trigger for the coronal phenomenon. It releases up to 10 26 J, accelerates up to 10 38 electrons and ions and must involve a volume that greatly exceeds the current sheet dimension. The Ramaty High-Energy Solar Spectroscopic Imager satellite can image a source in the corona that appears to contain the acceleration region and can separate it from other x-ray emissions. The new observations constrain the acceleration process by a quantitative relation between spectral index and flux. We present recent observational results and compare them with theoretical modelling by a stochastic process assuming transit-time damping of fast-mode waves, escape and replenishment. The observations can only be fitted if additional assumptions on trapping by an electric potential and possibly other processes such as isotropization and magnetic trapping are made

  20. Infrared observations of giant elliptical galaxies: (V-K) colors and the infrared Hubble diagram

    International Nuclear Information System (INIS)

    Grasdalen, G.L.

    1980-01-01

    The (V-K) colors of giant elliptical galaxies as a function of redshift are discussed. Present data are consistent with mild color evolution at z approximately 0.45. An infrared Hubble (redshift-magnitude) diagram is given. Cosmological models with q 0 =0 and no luminosity evolution are clearly excluded by the present data. A wide variety of models including those with q 0 =0 are permissible if luminosity evolution is included. Instrumental and programmatic implications of these results are summarized. (Auth.)

  1. Solar observations with a low frequency radio telescope

    Science.gov (United States)

    Myserlis, I.; Seiradakis, J.; Dogramatzidis, M.

    2012-01-01

    We have set up a low frequency radio monitoring station for solar bursts at the Observatory of the Aristotle University in Thessaloniki. The station consists of a dual dipole phased array, a radio receiver and a dedicated computer with the necessary software installed. The constructed radio receiver is based on NASA's Radio Jove project. It operates continuously, since July 2010, at 20.1 MHz (close to the long-wavelength ionospheric cut-off of the radio window) with a narrow bandwidth (~5 kHz). The system is properly calibrated, so that the recorded data are expressed in antenna temperature. Despite the high interference level of an urban region like Thessaloniki (strong broadcasting shortwave radio stations, periodic experimental signals, CBs, etc), we have detected several low frequency solar radio bursts and correlated them with solar flares, X-ray events and other low frequency solar observations. The received signal is monitored in ordinary ASCII format and as audio signal, in order to investigate and exclude man-made radio interference. In order to exclude narrow band interference and calculate the spectral indices of the observed events, a second monitoring station, working at 36 MHz, is under construction at the village of Nikiforos near the town of Drama, about 130 km away of Thessaloniki. Finally, we plan to construct a third monitoring station at 58 MHz, in Thessaloniki. This frequency was revealed to be relatively free of interference, after a thorough investigation of the region.

  2. PROBING THE SOLAR ATMOSPHERE USING OSCILLATIONS OF INFRARED CO SPECTRAL LINES

    International Nuclear Information System (INIS)

    Penn, M. J.; Schad, T.; Cox, E.

    2011-01-01

    Oscillations were observed across the whole solar disk using the Doppler shift and line center intensity of spectral lines from the CO molecule near 4666 nm with the National Solar Observatory's McMath/Pierce solar telescope. Power, coherence, and phase spectra were examined, and diagnostic diagrams reveal power ridges at the solar global mode frequencies to show that these oscillations are solar p-modes. The phase was used to determine the height of formation of the CO lines by comparison with the IR continuum intensity phase shifts as measured in Kopp et al.; we find that the CO line formation height varies from 425 km μ > 0.5. The velocity power spectra show that while the sum of the background and p-mode power increases with height in the solar atmosphere as seen in previous work, the power in the p-modes only (background subtracted) decreases with height. The CO line center intensity weakens in regions of stronger magnetic fields, as does the p-mode oscillation power. Across most of the solar surface the phase shift is larger than the expected value of 90 0 for an adiabatic atmosphere. We fit the phase spectra at different disk positions with a simple atmospheric model to determine that the acoustic cutoff frequency is about 4.5 mHz with only small variations, but that the thermal relaxation frequency drops significantly from 2.7 to 0 mHz at these heights in the solar atmosphere.

  3. Two Solar Tornadoes Observed with the Interface Region Imaging Spectrograph

    Science.gov (United States)

    Yang, Zihao; Tian, Hui; Peter, Hardi; Su, Yang; Samanta, Tanmoy; Zhang, Jingwen; Chen, Yajie

    2018-01-01

    The barbs or legs of some prominences show an apparent motion of rotation, which are often termed solar tornadoes. It is under debate whether the apparent motion is a real rotating motion, or caused by oscillations or counter-streaming flows. We present analysis results from spectroscopic observations of two tornadoes by the Interface Region Imaging Spectrograph. Each tornado was observed for more than 2.5 hr. Doppler velocities are derived through a single Gaussian fit to the Mg II k 2796 Å and Si IV 1393 Å line profiles. We find coherent and stable redshifts and blueshifts adjacent to each other across the tornado axes, which appears to favor the interpretation of these tornadoes as rotating cool plasmas with temperatures of 104 K–105 K. This interpretation is further supported by simultaneous observations of the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory, which reveal periodic motions of dark structures in the tornadoes. Our results demonstrate that spectroscopic observations can provide key information to disentangle different physical processes in solar prominences.

  4. Imaging Observations of Magnetic Reconnection in a Solar Eruptive Flare

    International Nuclear Information System (INIS)

    Li, Y.; Ding, M. D.; Sun, X.; Qiu, J.; Priest, E. R.

    2017-01-01

    Solar flares are among the most energetic events in the solar atmosphere. It is widely accepted that flares are powered by magnetic reconnection in the corona. An eruptive flare is usually accompanied by a coronal mass ejection, both of which are probably driven by the eruption of a magnetic flux rope (MFR). Here we report an eruptive flare on 2016 March 23 observed by the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory . The extreme-ultraviolet imaging observations exhibit the clear rise and eruption of an MFR. In particular, the observations reveal solid evidence of magnetic reconnection from both the corona and chromosphere during the flare. Moreover, weak reconnection is observed before the start of the flare. We find that the preflare weak reconnection is of tether-cutting type and helps the MFR to rise slowly. Induced by a further rise of the MFR, strong reconnection occurs in the rise phases of the flare, which is temporally related to the MFR eruption. We also find that the magnetic reconnection is more of 3D-type in the early phase, as manifested in a strong-to-weak shear transition in flare loops, and becomes more 2D-like in the later phase, as shown by the apparent rising motion of an arcade of flare loops.

  5. Imaging Observations of Magnetic Reconnection in a Solar Eruptive Flare

    Energy Technology Data Exchange (ETDEWEB)

    Li, Y.; Ding, M. D. [School of Astronomy and Space Science, Nanjing University, Nanjing 210023 (China); Sun, X. [W. W. Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305 (United States); Qiu, J. [Department of Physics, Montana State University, Bozeman, MT 59717 (United States); Priest, E. R., E-mail: yingli@nju.edu.cn [School of Mathematics and Statistics, University of St Andrews, Fife KY16 9SS, Scotland (United Kingdom)

    2017-02-01

    Solar flares are among the most energetic events in the solar atmosphere. It is widely accepted that flares are powered by magnetic reconnection in the corona. An eruptive flare is usually accompanied by a coronal mass ejection, both of which are probably driven by the eruption of a magnetic flux rope (MFR). Here we report an eruptive flare on 2016 March 23 observed by the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory . The extreme-ultraviolet imaging observations exhibit the clear rise and eruption of an MFR. In particular, the observations reveal solid evidence of magnetic reconnection from both the corona and chromosphere during the flare. Moreover, weak reconnection is observed before the start of the flare. We find that the preflare weak reconnection is of tether-cutting type and helps the MFR to rise slowly. Induced by a further rise of the MFR, strong reconnection occurs in the rise phases of the flare, which is temporally related to the MFR eruption. We also find that the magnetic reconnection is more of 3D-type in the early phase, as manifested in a strong-to-weak shear transition in flare loops, and becomes more 2D-like in the later phase, as shown by the apparent rising motion of an arcade of flare loops.

  6. Soil moisture estimation using reflected solar and emitted thermal infrared radiation

    Science.gov (United States)

    Jackson, R. D.; Cihlar, J.; Estes, J. E.; Heilman, J. L.; Kahle, A.; Kanemasu, E. T.; Millard, J.; Price, J. C.; Wiegand, C. L.

    1978-01-01

    Classical methods of measuring soil moisture such as gravimetric sampling and the use of neutron moisture probes are useful for cases where a point measurement is sufficient to approximate the water content of a small surrounding area. However, there is an increasing need for rapid and repetitive estimations of soil moisture over large areas. Remote sensing techniques potentially have the capability of meeting this need. The use of reflected-solar and emitted thermal-infrared radiation, measured remotely, to estimate soil moisture is examined.

  7. Multi-wavelength Observations of Solar Active Region NOAA 7154

    Science.gov (United States)

    Bruner, M. E.; Nitta, N. V.; Frank. Z. A.; Dame, L.; Suematsu, Y.

    2000-01-01

    We report on observations of a solar active region in May 1992 by the Solar Plasma Diagnostic Experiment (SPDE) in coordination with the Yohkoh satellite (producing soft X-ray images) and ground-based observatories (producing photospheric magnetograms and various filtergrams including those at the CN 3883 A line). The main focus is a study of the physical conditions of hot (T is approximately greater than 3 MK) coronal loops at their foot-points. The coronal part of the loops is fuzzy but what appear to be their footpoints in the transition region down to the photosphere are compact. Despite the morphological similarities, the footpoint emission at 10(exp 5) K is not quantitatively correlated with that at approximately 300 km above the tau (sub 5000) = 1 level, suggesting that the heat transport and therefore magnetic field topology in the intermediate layer is complicated. High resolution imaging observations with continuous temperature coverage are crucially needed.

  8. Far infrared extinction coefficients of minerals of interest for astronomical observations

    International Nuclear Information System (INIS)

    Hasegawa, H.

    1984-01-01

    Far infrared extinction coefficients of mineral grains of interest for astronomical observations have been measured. The measured mineral species are: amorphous carbon, high temperature magnesium silicates, hydrous silicates, iron oxides, and amorphous silicates. (author)

  9. Megapixel Longwave Infrared SLS FPAs for High Spatial Resolution Earth Observing Missions, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Earth observing missions like NASA's LANDSAT Data Continuity Mission - Thermal Infrared Sensor (LDCM-TIRS) require greater spatial resolution of the earth than the ~...

  10. Megapixel Longwave Infrared SLS FPAs for High Spatial Resolution Earth Observing Missions, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Earth observing missions like NASA's LANDSAT Data Continuity Mission - Thermal Infrared Sensor (LDCM-TIRS) require greater spatial resolution of the earth than the ~...

  11. MID-INFRARED PROPERTIES OF DISK AVERAGED OBSERVATIONS OF EARTH WITH AIRS

    International Nuclear Information System (INIS)

    Hearty, Thomas; Song, Inseok; Kim, Sam; Tinetti, Giovanna

    2009-01-01

    We have investigated mid-infrared spectra of Earth obtained by the Atmospheric Infrared Sounder (AIRS) instrument on-board the AQUA spacecraft to explore the characteristics that may someday be observed in extrasolar terrestrial planets. We have used the AIRS infrared (R ∼ 1200; 3.75-15.4 μm) spectra to construct directly observed high-resolution spectra of the only known life bearing planet, Earth. The AIRS spectra are the first such spectra that span the seasons. We investigate the rotational and seasonal spectral variations that would arise due to varying cloud amount and viewing geometry and we explore what signatures may be observable in the mid-infrared by the next generation of telescopes capable of observing extrasolar terrestrial planets.

  12. Observations of the solar wind speed near the sun

    International Nuclear Information System (INIS)

    Grall, R. R.; Coles, Wm. A.; Klinglesmith, M. T.

    1996-01-01

    Two-antenna scintillation (IPS) observations can provide accurate measurements of the velocity with which electron density fluctuations drift past the line of sight. These fluctuations can be used as tracers for the solar plasma and allow us to estimate the solar wind velocity near the Sun where spacecraft have not yet penetrated. We present recent IPS measurements made with the EISCAT and VLBA arrays. We have found that by using baselines which are several times the scale size of the diffraction pattern we are able to partially deconvolve the line of sight integration which affects remote sensing data. The long baselines allow the fast and slow components of the solar wind to be separated and their velocities estimated individually. In modeling IPS it is important that the scattering be 'weak' because the model then requires only 1 spatial parameter instead of 3. EISCAT can only operate near 933MHz which limits the observation to outside of 18R · , however the VLBA has higher frequency receivers which allow it to observe inside of 15R · . The density variance δN e 2 in the fast wind is a factor of 10-15 less than in the slow (Coles et al., 1995) making it necessary to consider the entire line of sight, particularly when the fast wind occupies the center portion. Using the point of closest approach and the average velocity to characterize the observation can lead to an incorrect interpretation of the data. We have compared our IPS observations with maps made from the Yohkoh soft X ray, HAO's white-light electron density, and Stanford magnetic field measurements as well as with the IMP8 and Ulysses spacecraft data to assist in placing the fast and slow wind. Here we have selected those observation from 1994 which were dominated by the southern coronal hole and have estimated a velocity acceleration profile for the fast solar wind between 7 and 100R · which is presented in Figure 1. The observations suggest that the fast solar wind is fully developed by ≅7R

  13. Infrared-faint radio sources remain undetected at far-infrared wavelengths. Deep photometric observations using the Herschel Space Observatory

    Science.gov (United States)

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

    2015-08-01

    Context. Showing 1.4 GHz flux densities in the range of a few to a few tens of mJy, infrared-faint radio sources (IFRS) are a type of galaxy characterised by faint or absent near-infrared counterparts and consequently extreme radio-to-infrared flux density ratios up to several thousand. Recent studies showed that IFRS are radio-loud active galactic nuclei (AGNs) at redshifts ≳2, potentially linked to high-redshift radio galaxies (HzRGs). Aims: This work explores the far-infrared emission of IFRS, providing crucial information on the star forming and AGN activity of IFRS. Furthermore, the data enable examining the putative relationship between IFRS and HzRGs and testing whether IFRS are more distant or fainter siblings of these massive galaxies. Methods: A sample of six IFRS was observed with the Herschel Space Observatory between 100 μm and 500 μm. Using these results, we constrained the nature of IFRS by modelling their broad-band spectral energy distribution (SED). Furthermore, we set an upper limit on their infrared SED and decomposed their emission into contributions from an AGN and from star forming activity. Results: All six observed IFRS were undetected in all five Herschel far-infrared channels (stacking limits: σ = 0.74 mJy at 100 μm, σ = 3.45 mJy at 500 μm). Based on our SED modelling, we ruled out the following objects to explain the photometric characteristics of IFRS: (a) known radio-loud quasars and compact steep-spectrum sources at any redshift; (b) starburst galaxies with and without an AGN and Seyfert galaxies at any redshift, even if the templates were modified; and (c) known HzRGs at z ≲ 10.5. We find that the IFRS analysed in this work can only be explained by objects that fulfil the selection criteria of HzRGs. More precisely, IFRS could be (a) known HzRGs at very high redshifts (z ≳ 10.5); (b) low-luminosity siblings of HzRGs with additional dust obscuration at lower redshifts; (c) scaled or unscaled versions of Cygnus A at any

  14. Solar Flares Observed with the Ramaty High Energy Solar Spectroscopic Imager (RHESSI)

    Science.gov (United States)

    Holman, Gordon D.

    2004-01-01

    Solar flares are impressive examples of explosive energy release in unconfined, magnetized plasma. It is generally believed that the flare energy is derived from the coronal magnetic field. However, we have not been able to establish the specific energy release mechanism(s) or the relative partitioning of the released energy between heating, particle acceleration (electrons and ions), and mass motions. NASA's RHESSI Mission was designed to study the acceleration and evolution of electrons and ions in flares by observing the X-ray and gamma-ray emissions these energetic particles produce. This is accomplished through the combination of high-resolution spectroscopy and spectroscopic imaging, including the first images of flares in gamma rays. RHESSI has observed over 12,000 solar flares since its launch on February 5, 2002. I will demonstrate how we use the RHESSI spectra to deduce physical properties of accelerated electrons and hot plasma in flares. Using images to estimate volumes, w e typically find that the total energy in accelerated electrons is comparable to that in the thermal plasma. I will also present flare observations that provide strong support for the presence of magnetic reconnection in a large-scale, vertical current sheet in the solar corona. RHESSI observations such as these are allowing us to probe more deeply into the physics of solar flares.

  15. Infrared, radio, and x-ray observations of Cygnus X-3

    International Nuclear Information System (INIS)

    Becklin, E.E.; Hawkins, F.J.; Mason, K.O.; Matthews, K.; Neugebauer, G.; Packman, D.; Sanford, P.W.; Schupler, B.; Stark, A.; Wynn-Williams, C.G.

    1974-01-01

    The x-ray source Cygnus X-3 has been interpreted as being a binary system on the basis of extensive x-ray observations of periodic variability. At radio wavelengths, the source displays erratic outbursts. Cyg x-3 has not been detected visually but at infrared wavelengths periodic variations in phase with the x-ray variations have been reported. Infrared, x-ray and radio observations of Cyg X-3 made during 1973 through 1973 October are presented. (U.S.)

  16. YOHKOH Observations at the Y2K Solar Maximum

    Science.gov (United States)

    Aschwanden, M. J.

    1999-05-01

    Yohkoh will provide simultaneous co-aligned soft X-ray and hard X-ray observations of solar flares at the coming solar maximum. The Yohkoh Soft X-ray Telescope (SXT) covers the approximate temperature range of 2-20 MK with a pixel size of 2.46\\arcsec, and thus complements ideally the EUV imagers sensitive in the 1-2 MK plasma, such as SoHO/EIT and TRACE. The Yohkoh Hard X-ray Telescope (HXT) offers hard X-ray imaging at 20-100 keV at a time resolution of down to 0.5 sec for major events. In this paper we review the major SXT and HXT results from Yohkoh solar flare observations, and anticipate some of the key questions that can be addressed through joint observations with other ground and space-based observatories. This encompasses the dynamics of flare triggers (e.g. emerging flux, photospheric shear, interaction of flare loops in quadrupolar geometries, large-scale magnetic reconfigurations, eruption of twisted sigmoid structures, coronal mass ejections), the physics of particle dynamics during flares (acceleration processes, particle propagation, trapping, and precipitation), and flare plasma heating processes (chromospheric evaporation, coronal energy loss by nonthermal particles). In particular we will emphasize on how Yohkoh data analysis is progressing from a qualitative to a more quantitative science, employing 3-dimensional modeling and numerical simulations.

  17. concentrated solar power and solar thermal Barometer - EurObserv'ER - May 2015

    International Nuclear Information System (INIS)

    2015-05-01

    European concentrated solar power capacity remained stable in 2014 and will probably post a negligible increase in 2015. Construction work on a number of new facilities in Italy that are scheduled for commissioning in 2016 and 2017 could commence in the second half of the year. The European solar thermal market for producing heat, domestic hot water and heating has not found the recipe for recovery. According to EurObserv'ER, the market contracted by a further 3.7% from its 2013 level which is the sixth decrease in a row

  18. Tropospheric and total ozone columns over Paris (France measured using medium-resolution ground-based solar-absorption Fourier-transform infrared spectroscopy

    Directory of Open Access Journals (Sweden)

    C. Viatte

    2011-10-01

    Full Text Available Ground-based Fourier-transform infrared (FTIR solar absorption spectroscopy is a powerful remote sensing technique providing information on the vertical distribution of various atmospheric constituents. This work presents the first evaluation of a mid-resolution ground-based FTIR to measure tropospheric ozone, independently of stratospheric ozone. This is demonstrated using a new atmospheric observatory (named OASIS for "Observations of the Atmosphere by Solar absorption Infrared Spectroscopy", installed in Créteil (France. The capacity of the technique to separate stratospheric and tropospheric ozone is demonstrated. Daily mean tropospheric ozone columns derived from the Infrared Atmospheric Sounding Interferometer (IASI and from OASIS measurements are compared for summer 2009 and a good agreement of −5.6 (±16.1 % is observed. Also, a qualitative comparison between in-situ surface ozone measurements and OASIS data reveals OASIS's capacity to monitor seasonal tropospheric ozone variations, as well as ozone pollution episodes in summer 2009 around Paris. Two extreme pollution events are identified (on the 1 July and 6 August 2009 for which ozone partial columns from OASIS and predictions from a regional air-quality model (CHIMERE are compared following strict criteria of temporal and spatial coincidence. An average bias of 0.2%, a mean square error deviation of 7.6%, and a correlation coefficient of 0.91 is found between CHIMERE and OASIS, demonstrating the potential of a mid-resolution FTIR instrument in ground-based solar absorption geometry for tropospheric ozone monitoring.

  19. Solar energetic particles: observational studies and magnetohydrodynamic simulation

    International Nuclear Information System (INIS)

    Masson, S.

    2010-10-01

    Solar activity manifests itself through highly dynamical events, such as flares and coronal mass ejections, which result in energy release by magnetic reconnection. This thesis focuses on two manifestations of this energy release: solar energetic particles and dynamics of magnetic reconnection. The first part of my work consists in the detailed temporal analysis of several electromagnetic signatures, produced by energetic particles in the solar atmosphere, with respect to the energetic particle flux at Earth. Using multi-instrument observations, I highlighted that particles can be accelerated by the flare to relativistic energies during a specific episode of acceleration in the impulsive phase. This showed that particles traveled a longer path length than the theoretical length generally assumed. Using in-situ measurements of magnetic field and plasma, I identified the interplanetary magnetic field for 10 particle events, and performing a velocity dispersion analysis I obtained the interplanetary length traveled by particles. I showed that the magnetic structure of the interplanetary medium play a crucial role in the association of the particle flux at Earth and the acceleration signatures of particles at the Sun. The second part of my work focuses on the dynamics of magnetic reconnection. Observationally, the best evidence for magnetic reconnection is the appearance of brightnesses at the solar surface. Performing the first data-driven 3 dimensional magneto-hydrodynamic (MHD) simulation of an observed event, I discovered that the evolution of brightnesses can be explained by the succession of two different reconnection regimes, induced by a new topological association where null-point separatrix lines are embedded in quasi-separatrix layers. This new topological association induces a change of field line connectivity, but also a continuous reconnection process, leading to an apparent slipping motion of reconnected field lines. From a MHD simulation I showed that

  20. 8 years of Solar Spectral Irradiance Variability Observed from the ISS with the SOLAR/SOLSPEC Instrument

    Science.gov (United States)

    Damé, Luc; Bolsée, David; Meftah, Mustapha; Irbah, Abdenour; Hauchecorne, Alain; Bekki, Slimane; Pereira, Nuno; Cessateur, Marchand; Gäel; , Marion; et al.

    2016-10-01

    Accurate measurements of Solar Spectral Irradiance (SSI) are of primary importance for a better understanding of solar physics and of the impact of solar variability on climate (via Earth's atmospheric photochemistry). The acquisition of a top of atmosphere reference solar spectrum and of its temporal and spectral variability during the unusual solar cycle 24 is of prime interest for these studies. These measurements are performed since April 2008 with the SOLSPEC spectro-radiometer from the far ultraviolet to the infrared (166 nm to 3088 nm). This instrument, developed under a fruitful LATMOS/BIRA-IASB collaboration, is part of the Solar Monitoring Observatory (SOLAR) payload, externally mounted on the Columbus module of the International Space Station (ISS). The SOLAR mission, with its actual 8 years duration, will cover almost the entire solar cycle 24. We present here the in-flight operations and performances of the SOLSPEC instrument, including the engineering corrections, calibrations and improved know-how procedure for aging corrections. Accordingly, a SSI reference spectrum from the UV to the NIR will be presented, together with its variability in the UV, as measured by SOLAR/SOLSPEC for 8 years. Uncertainties on these measurements and comparisons with other instruments will be briefly discussed.

  1. Local observables in a landscape of infrared gauge modes

    Energy Technology Data Exchange (ETDEWEB)

    Thorsrud, Mikjel; Mota, David F. [Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, N-0315 Oslo (Norway); Urban, Federico R. [Service de Physique Théorique, Université Libre de Bruxelles, CP225, Boulevard du Triomphe, B-1050 Brussels (Belgium)

    2014-06-02

    Cosmological local observables are at best statistically determined by the fundamental theory describing inflation. When the scalar inflaton is coupled uniformly to a collection of subdominant massless gauge vectors, rotational invariance is obeyed locally. However, the statistical isotropy of fluctuations is spontaneously broken by gauge modes whose wavelength exceeds our causal horizon. This leads to a landscape picture where primordial correlators depend on the position of the observer. We compute the stochastic corrections to the curvature power spectrum, show the existence of a new local observable (the shape of the quadrupole), and constrain the theory using Planck limits.

  2. Solar thermal and concentrated solar power barometer - EurObserv'ER - May 2013

    International Nuclear Information System (INIS)

    2013-05-01

    The European concentrated solar power plant market is steeling itself for tough time ahead. The number of projects under construction is a pittance compared with 2012 that was an excellent year for installations (an additional 802.5 MW of capacity recorded). This drop is the result of the moratorium on renewable energy power plants introduced by the Spanish government. The European solar thermal market is hardly any more encouraging. EurObserv'ER holds that it slipped for the fourth year in a row (it dropped 5.5% between 2011 and 2012). The newly-installed solar thermal collector surface area in the EU now stands at 3.4 million m 2 , far short of its 2008 installation record of 4.6 million m 2

  3. Properties of solar gravity mode signals in total irradiance observations

    International Nuclear Information System (INIS)

    Kroll, R.J.; Chen, J.; Hill, H.A.

    1988-01-01

    Further evidence has been found that a significant fraction of the gravity mode power density in the total irradiance observations appears in sidebands of classified eigenfrequencies. These sidebands whose amplitudes vary from year to year are interpreted as harmonics of the rotational frequencies of the nonuniform solar surface. These findings are for non axisymmetric modes and corroborate the findings of Kroll, Hill and Chen for axisymmetric modes. It is demonstrated the the generation of the sidebands lifts the usual restriction on the parity of the eigenfunctions for modes detectable in total irradiance observations. 14 refs

  4. Infrared galaxies evolution. From cosmological observations with ISO to a mid-infrared to sub-millimetric modeling

    International Nuclear Information System (INIS)

    Dole, Herve

    2000-01-01

    This thesis deals with the analysis of the FIRBACK deep survey performed in the far infrared at λ=170 μm with the Infrared Space Observatory whose aim is the study of the galaxies contributing to the Cosmic Infrared Background, and with the modelling of galaxy evolution in the mid-infrared to submillimeter range. The FIRBACK survey covers 3. 89 Sq. Deg. in 3 high galactic latitude and low foreground emission fields (2 of which are in the northern sky). I first present the techniques of reduction, processing and calibration of the ISOPHOT cosmological data. I show that there is a good agreement between PHOT and DIRBE on extended emission, thanks to the derivation of the PHOT footprint. Final maps are created, and the survey is confusion limited at σc=45 mJy. I present then the techniques of source extraction and the simulations for photometry needed to build the final catalog of 106 sources between 180 mJy (4σ) and 2.4 Jy. The complementary catalog is made of 90 sources between 135 and 180 mJy. Galaxy counts show a large excess with respect to local counts or models (with and without evolution), only compatible with strong evolution scenarios. The Cosmic Infrared Background (CIB) is resolved at 4 % at 170 μm. The identifications of the sources at other wavelengths suggest that most of the sources are local, but a non-negligible part lies above redshift 1. I have developed a phenomenological model of galaxy evolution in order to constrain galaxy evolution in the infrared and to have a better understanding of what the FIRBACK sources are. Using the local Luminosity Function (LF), and template spectra of starburst galaxies, it is possible to constrain the evolution of the LF using all the available data: deep source counts at 15, 170 and 850 μm and the CIB spectrum. I show that galaxy evolution is dominated by a high infrared luminosity population, peaking at L=2.0*10"1"1 Redshift distributions are in agreement with available observations. Predictions are

  5. Solar observations with the prototype of the Brazilian Decimetric Array

    Science.gov (United States)

    Sawant, H. S.; Ramesh, R.; Faria, C.; Cecatto, J. R.; Fernandes, F. C. R.; Madsen, F. H. R.; Subramanian, K. R.; Sundararajan, M. S.

    The prototype of the Brazilian Decimetric Array BDA consists of 5 element alt-az mounted parabolic mesh type dishes of 4-meter diameter having base lines up to 220 meters in the E--W direction The array was put into regular operation at Cachoeira Paulista Brazil longitude 45 r 00 20 W and latitude 22 r 41 19 S This array operates in the frequency range of 1 2 -- 1 7 GHz Solar observations are carried at sim 1 4 GHz in transit and tracking modes Spatial fine structures superimposed on the one dimensional brightness map of the sun associated with active regions and or with solar activity and their time evolution will be presented In the second phase of the project the frequency range will be increased to 1 2 - 1 7 2 8 and 5 6 GHz Central part of the array will consist of 26 antennas with 4-meter diameter laid out randomically in the square of 256 by 256 meter with minimum and maximum base lines of 8 and 256 meters respectively Details of this array with imaging capabilities in snap shot mode for solar observations and procedure of the phase and amplitude calibrations will be presented The development of instrument will be completed by the beginning of 2008

  6. A solar observing station for education and research in Peru

    Science.gov (United States)

    Kaname, José Iba, Ishitsuka; Ishitsuka, Mutsumi; Trigoso Avilés, Hugo; Takashi, Sakurai; Yohei, Nishino; Miyazaki, Hideaki; Shibata, Kazunari; Ueno, Satoru; Yumoto, Kiyohumi; Maeda, George

    2007-12-01

    Since 1937 Carnegie Institution of Washington made observations of active regions of the Sun with a Hale type spectro-helioscope in Huancayo observatory of the Instituto Geofísico del Perú (IGP). IGP has contributed significantly to geophysical and solar sciences in the last 69 years. Now IGP and the Faculty of Sciences of the Universidad Nacional San Luis Gonzaga de Ica (UNICA) are planning to refurbish the coelostat at the observatory with the support of National Astronomical Observatory of Japan. It is also planned to install a solar Flare Monitor Telescope (FMT) at UNICA, from Hida observatory of Kyoto University. Along with the coelostat, the FMT will be useful to improve scientific research and education.

  7. Soft x-ray spectrographs for solar observations

    International Nuclear Information System (INIS)

    Bruner, M.E.

    1988-01-01

    This paper surveys some of the recent advances in the state of the art of soft X-ray spectrometers, particularly as they might be applied to Solar Observations. The discussions center on the windowless region from roughly 1 to 100 A, and covers both grating and crystal instruments. The author begins with a short discussion of the solar soft X-ray spectrum and its interpretation, followed by a few general comments on problems peculiar to soft X-ray instruments. The paper reviews of recent developments in spectrometer optical design, which has been a lively field during the last dozen years. This is particularly true in the case of grating spectrometers. The paper concludes with a short section on telescope considerations, and some remarks on future flight opportunities

  8. Mars Infrared Spectroscopy: From Theory and the Laboratory To Field Observations

    Science.gov (United States)

    Kirkland, Laurel (Editor); Mustard, John (Editor); McAfee, John (Editor); Hapke, Bruce (Editor); Ramsey, Michael (Editor)

    2002-01-01

    The continuity and timely implementation of the Mars exploration strategy relies heavily on the ability of the planetary community to interpret infrared spectral data. However, the increasing mission rate, data volume, and data variety, combined with the small number of spectroscopists within the planetary community, will require a coordinated community effort for effective and timely interpretation of the newly acquired and planned data sets. Relevant spectroscopic instruments include the 1996 TES, 2001 THEMIS, 2003 Pancam, 2003 Mini-TES, 2003 Mars Express OMEGA, 2003 Mars Express PFS, and 2005 CFUSM. In light of that, leaders of the Mars spectral community met June 4-6 to address the question: What terrestrial theoretical, laboratory, and field studies are most needed to best support timely interpretations of current and planned visible infrared spectrometer data sets, in light of the Mars Program goals? A primary goal of the spectral community is to provide a reservoir of information to enhance and expand the exploration of Mars. Spectroscopy has a long history of providing the fundamental compositional discoveries in the solar system, from atmospheric constituents to surface mineralogy, from earth-based to spacecraft-based observations. However, such spectroscopic compositional discoveries, especially surface mineralogies, have usually come after long periods of detailed integration of remote observations, laboratory analyses, and field measurements. Spectroscopic information of surfaces is particularly complex and often is confounded by interference of broad, overlapping absorption features as well as confusing issues of mixtures, coatings, and grain size effects. Thus some spectroscopic compositional discoveries have come only after many years of research. However, we are entering an era of Mars exploration with missions carrying sophisticated spectrometers launching about every 2 years. It is critical that each mission provide answers to relevant questions

  9. Simultaneous Solar Maximum Mission (SMM) and very large array observations of solar active regions

    Science.gov (United States)

    Lang, K. R.

    1986-01-01

    The research deals mainly with Very Large Array and Solar Maximum Mission observations of the ubiquitous coronal loops that dominate the structure of the low corona. As illustrated, the observations of thermal cyclotron lines at microwave wavelengths provide a powerful new method of accurately specifying the coronal magnetic field strength. Processes are delineated that trigger solar eruptions from coronal loops, including preburst heating and the magnetic interaction of coronal loops. Evidence for coherent burst mechanisms is provided for both the Sun and nearby stars, while other observations suggest the presence of currents that may amplify the coronal magnetic field to unexpectedly high levels. The existence is reported of a new class of compact, variable moving sources in regions of apparently weak photospheric field.

  10. Near-Infrared Photon-Counting Camera for High-Sensitivity Observations

    Science.gov (United States)

    Jurkovic, Michael

    2012-01-01

    The dark current of a transferred-electron photocathode with an InGaAs absorber, responsive over the 0.9-to-1.7- micron range, must be reduced to an ultralow level suitable for low signal spectral astrophysical measurements by lowering the temperature of the sensor incorporating the cathode. However, photocathode quantum efficiency (QE) is known to reduce to zero at such low temperatures. Moreover, it has not been demonstrated that the target dark current can be reached at any temperature using existing photocathodes. Changes in the transferred-electron photocathode epistructure (with an In- GaAs absorber lattice-matched to InP and exhibiting responsivity over the 0.9- to-1.7- m range) and fabrication processes were developed and implemented that resulted in a demonstrated >13x reduction in dark current at -40 C while retaining >95% of the approximately equal to 25% saturated room-temperature QE. Further testing at lower temperature is needed to confirm a >25 C predicted reduction in cooling required to achieve an ultralow dark-current target suitable for faint spectral astronomical observations that are not otherwise possible. This reduction in dark current makes it possible to increase the integration time of the imaging sensor, thus enabling a much higher near-infrared (NIR) sensitivity than is possible with current technology. As a result, extremely faint phenomena and NIR signals emitted from distant celestial objects can be now observed and imaged (such as the dynamics of redshifting galaxies, and spectral measurements on extra-solar planets in search of water and bio-markers) that were not previously possible. In addition, the enhanced NIR sensitivity also directly benefits other NIR imaging applications, including drug and bomb detection, stand-off detection of improvised explosive devices (IED's), Raman spectroscopy and microscopy for life/physical science applications, and semiconductor product defect detection.

  11. Patient observers and non-perturbative infrared dynamics in inflation

    DEFF Research Database (Denmark)

    Ferreira, Ricardo Z.; Sandora, McCullen; Sloth, Martin S.

    2018-01-01

    observer who has lived long enough to have a record of the state before the soft mode was created. Though classically there is no obstruction to measuring this effect locally, we give several indications that quantum mechanical uncertainties may censor the effect. We then apply our methods to find a non...

  12. Far-infared spectroscopic observations with a Balloon-Borne infrared telescope

    International Nuclear Information System (INIS)

    Maihara, Toshinori; Takami, Hideki; Mizutani, Kohei

    1986-01-01

    The first observations of far-infrared celestial objects using the 50-cm Balloon-Borne Infrared Telescope were made in Alice Springs, Australia. Far-infrared spectrophotometric data between 45 and 115 μm were taken for the Orion-KL region, Saturn and a southern H II region RCW 38. The data including high excitation transition lines of CO for Orion-KL, O III lines for RCW 38 and a PH 3 absorption feature of Saturn will be presented. (author)

  13. Observation of near-infrared surface brightness of the large Magellanic cloud

    International Nuclear Information System (INIS)

    Hayakawa, Satio; Koizumi, Yutaka; Matsumoto, Toshio; Murakami, Hiroshi; Uyama, Kiichiro.

    1981-01-01

    The near-infrared surface brightness of the large Magellanic cloud was observed by an infrared telescope carried by a balloon. The balloon flight was made at Australian Balloon Launching Station. The brightness distribution of 2.4 Mu m radiation was obtained. A part of Bar was bright, and the expansion of the contour at the east end of Bar corresponded to the 30 Dor region. Many near-infrared sources distribute in this region. Discussions on the color and brightness of the center of Bar and the 30 Dor region are presented. (Kato, T.)

  14. Far-infrared observations of Sagittarius B2 - reconsideration of source structure

    International Nuclear Information System (INIS)

    Thronson, H.A. Jr.; Harper, D.A.; Yerkes Observatory, Williams Bay, WI)

    1986-01-01

    New moderate-angular-resolution far-infrared observations of the Sagittarius B2 star-forming region are presented, discussed, and compared with recent radio molecular and continuum observations of this source. In contrast to previous analyses, its far-infrared spectrum is interpreted as the result of a massive frigid cloud overlying a more-or-less normal infrared source, a natural explanation for the object's previously-noted peculiarities. The characteristics derived for the obscuring cloud are similar to those found for the W51 MAIN object. Both sources have high sub-millimeter surface brightness, a high ratio of sub-millimeter to far-infrared flux, and numerous regions of molecular maser emission. 28 references

  15. Observation of solar flare by Hinotori SXT/HXM

    International Nuclear Information System (INIS)

    Ohki, Ken-ichiro; Takakura, Tatsuo; Tsuneta, Sukehisa; Nitta, Nariaki; Makishima, Kazuo.

    1982-01-01

    Solar flares were observed by SXT (hard X-ray two-dimensional observation system) and HXM (hard X-ray spectrometer) on Hinotori. The results of two-dimensional analysis of 20 flares are reported in this paper. Various images of hard X-ray were observed. Hard X-ray bursts with relatively long duration may be generated in corona. The hard X-ray flare generated on the solar disc gives information on the relative position to the H flare. The examples of this hard X-ray images are presented. The HXM can observe the hard X-ray spectra up to 350 keV. The flares with duration less than 5 min have the spectra coninciding with the thermal radiation from a single temperature before the peak, and power law type non-thermal radiation spectra after the peak. The hard X-ray flares with duration longer than 10 min have power law type spectra. (Kato, T.)

  16. ON THE OBSERVATION AND SIMULATION OF SOLAR CORONAL TWIN JETS

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jiajia; Wang, Yuming; Zhang, Quanhao [CAS Key Laboratory of Geospace Environment, School of Earth and Space Sciences, University of Science and Technology of China, NO. 96, Jinzhai Road, Hefei, Anhui 230026 (China); Fang, Fang [Laboratory for Atmospheric and Space Physics, University of Colorado at Boulder, 1234 Innovation Drive, Boulder, CO 80303 (United States); McIntosh, Scott W.; Fan, Yuhong [High Altitude Observatory, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307 (United States)

    2016-02-01

    We present the first observation, analysis, and modeling of solar coronal twin jets, which occurred after a preceding jet. Detailed analysis on the kinetics of the preceding jet reveals its blowout-jet nature, which resembles the one studied in Liu et al. However, the erupting process and kinetics of the twin jets appear to be different from the preceding one. Lacking detailed information on the magnetic fields in the twin jet region, we instead use a numerical simulation using a three-dimensional (3D) MHD model as described in Fang et al., and find that in the simulation a pair of twin jets form due to reconnection between the ambient open fields and a highly twisted sigmoidal magnetic flux, which is the outcome of the further evolution of the magnetic fields following the preceding blowout jet. Based on the similarity between the synthesized and observed emission, we propose this mechanism as a possible explanation for the observed twin jets. Combining our observation and simulation, we suggest that with continuous energy transport from the subsurface convection zone into the corona, solar coronal twin jets could be generated in the same fashion addressed above.

  17. On the Observation and Simulation of Solar Coronal Twin Jets

    Science.gov (United States)

    Liu, Jiajia; Fang, Fang; Wang, Yuming; McIntosh, Scott W.; Fan, Yuhong; Zhang, Quanhao

    2016-02-01

    We present the first observation, analysis, and modeling of solar coronal twin jets, which occurred after a preceding jet. Detailed analysis on the kinetics of the preceding jet reveals its blowout-jet nature, which resembles the one studied in Liu et al. However, the erupting process and kinetics of the twin jets appear to be different from the preceding one. Lacking detailed information on the magnetic fields in the twin jet region, we instead use a numerical simulation using a three-dimensional (3D) MHD model as described in Fang et al., and find that in the simulation a pair of twin jets form due to reconnection between the ambient open fields and a highly twisted sigmoidal magnetic flux, which is the outcome of the further evolution of the magnetic fields following the preceding blowout jet. Based on the similarity between the synthesized and observed emission, we propose this mechanism as a possible explanation for the observed twin jets. Combining our observation and simulation, we suggest that with continuous energy transport from the subsurface convection zone into the corona, solar coronal twin jets could be generated in the same fashion addressed above.

  18. HEMISPHERIC ASYMMETRIES IN THE POLAR SOLAR WIND OBSERVED BY ULYSSES NEAR THE MINIMA OF SOLAR CYCLES 22 AND 23

    International Nuclear Information System (INIS)

    Ebert, R. W.; Dayeh, M. A.; Desai, M. I.; McComas, D. J.; Pogorelov, N. V.

    2013-01-01

    We examined solar wind plasma and interplanetary magnetic field (IMF) observations from Ulysses' first and third orbits to study hemispheric differences in the properties of the solar wind and IMF originating from the Sun's large polar coronal holes (PCHs) during the declining and minimum phase of solar cycles 22 and 23. We identified hemispheric asymmetries in several parameters, most notably ∼15%-30% south-to-north differences in averages for the solar wind density, mass flux, dynamic pressure, and energy flux and the radial and total IMF magnitudes. These differences were driven by relatively larger, more variable solar wind density and radial IMF between ∼36°S-60°S during the declining phase of solar cycles 22 and 23. These observations indicate either a hemispheric asymmetry in the PCH output during the declining and minimum phase of solar cycles 22 and 23 with the southern hemisphere being more active than its northern counterpart, or a solar cycle effect where the PCH output in both hemispheres is enhanced during periods of higher solar activity. We also report a strong linear correlation between these solar wind and IMF parameters, including the periods of enhanced PCH output, that highlight the connection between the solar wind mass and energy output and the Sun's magnetic field. That these enhancements were not matched by similar sized variations in solar wind speed points to the mass and energy responsible for these increases being added to the solar wind while its flow was subsonic.

  19. Broadband dye-sensitized upconverting nanocrystals enabled near-infrared planar perovskite solar cells

    Science.gov (United States)

    Lai, Xuesen; Li, Xitao; Lv, Xinding; Zheng, Yan-Zhen; Meng, Fanli; Tao, Xia

    2017-12-01

    Extending the spectral absorption of perovskite solar cells (PSCs) from visible into near-infrared (NIR) range is a promising strategy to minimize non-absorption loss of solar photons and enhance the cell photovoltaic performance. Herein, we report on for the first time a viable strategy of incorporating IR806 dye-sensitized upconversion nanocrystals (IR806-UCNCs) into planar PSC for broadband upconversion of NIR light (800-1000 nm) into perovskite absorber-responsive visible emissions. A smart trick is firstly adopted to prepare hydrophilic IR806-UCNCs via a NOBF4 assisted two-step ligand-exchange that allows incorporating with perovskite precursor for in-situ growth of upconverting planar perovskite film. Unlike typically reported upconverting nanoparticles with narrow NIR absorption, the as-prepared IR806-UCNCs are able to harvest NIR light broadly and then transfer the captured energy to the UCNCs for an efficient visible upconversion. The IR806-UCNCs-incorporated cell exhibits a power conversion efficiency of 17.49%, corresponding to 29% increment from that of the pristine cell (13.52%). This strategy provides a feasible way to enable the most efficient harvesting of NIR sunlight for solar cells and other optoelectric devices.

  20. Simultaneous Solar Maximum Mission (SMM) and Very Large Array (VLA) observations of solar active regions

    Science.gov (United States)

    Willson, Robert F.

    1991-01-01

    Very Large Array observations at 20 cm wavelength can detect the hot coronal plasma previously observed at soft x ray wavelengths. Thermal cyclotron line emission was detected at the apex of coronal loops where the magnetic field strength is relatively constant. Detailed comparison of simultaneous Solar Maximum Mission (SMM) Satellite and VLA data indicate that physical parameters such as electron temperature, electron density, and magnetic field strength can be obtained, but that some coronal loops remain invisible in either spectral domain. The unprecedent spatial resolution of the VLA at 20 cm wavelength showed that the precursor, impulsive, and post-flare components of solar bursts originate in nearby, but separate loops or systems of loops.. In some cases preburst heating and magnetic changes are observed from loops tens of minutes prior to the impulsive phase. Comparisons with soft x ray images and spectra and with hard x ray data specify the magnetic field strength and emission mechanism of flaring coronal loops. At the longer 91 cm wavelength, the VLA detected extensive emission interpreted as a hot 10(exp 5) K interface between cool, dense H alpha filaments and the surrounding hotter, rarefield corona. Observations at 91 cm also provide evidence for time-correlated bursts in active regions on opposite sides of the solar equator; they are attributed to flare triggering by relativistic particles that move along large-scale, otherwise-invisible, magnetic conduits that link active regions in opposite hemispheres of the Sun.

  1. Bio-inspired Plasmonic Nanoarchitectured Hybrid System Towards Enhanced Far Red-to-Near Infrared Solar Photocatalysis

    OpenAIRE

    Runyu Yan; Min Chen; Han Zhou; Tian Liu; Xingwei Tang; Ke Zhang; Hanxing Zhu; Jinhua Ye; Di Zhang; Tongxiang Fan

    2016-01-01

    Solar conversion to fuels or to electricity in semiconductors using far red-to-near infrared (NIR) light, which accounts for about 40% of solar energy, is highly significant. One main challenge is the development of novel strategies for activity promotion and new basic mechanisms for NIR response. Mother Nature has evolved to smartly capture far red-to-NIR light via their intelligent systems due to unique micro/nanoarchitectures, thus motivating us for biomimetic design. Here we report the fi...

  2. GAP: yet another image processing system for solar observations.

    Science.gov (United States)

    Keller, C. U.

    GAP is a versatile, interactive image processing system for analyzing solar observations, in particular extended time sequences, and for preparing publication quality figures. It consists of an interpreter that is based on a language with a control flow similar to PASCAL and C. The interpreter may be accessed from a command line editor and from user-supplied functions, procedures, and command scripts. GAP is easily expandable via external FORTRAN programs that are linked to the GAP interface routines. The current version of GAP runs on VAX, DECstation, Sun, and Apollo computers. Versions for MS-DOS and OS/2 are in preparation.

  3. Initiation of Solar Eruptions: Recent Observations and Implications for Theories

    Science.gov (United States)

    Sterling, A. C.

    2006-01-01

    Solar eruptions involve the violent disruption of a system of magnetic field. Just how the field is destabilized and explodes to produce flares and coronal mass ejections (CMEs) is still being debated in the solar community. Here I discuss recent observational work into these questions by ourselves (me and my colleagues) and others. Our work has concentrated mainly on eruptions that include filaments. We use the filament motion early in the event as a tracer of the motion of the general erupting coronal field in and around the filament, since that field itself is hard to distinguish otherwise. Our main data sources are EUV images from SOHO/EIT and TRACE, soft Xray images from Yohkoh, and magnetograms from SOHO/MDI, supplemented with coronagraph images from SOHO/LASCO, hard X-ray data, and ground-based observations. We consider the observational findings in terms of three proposed eruption-initiation mechanisms: (i) runaway internal tether-cutting reconnection, (ii) slow external tether-cutting reconnection ("breakout"), and (iii) ideal MHD instability.

  4. Infrared observations of circumstellar ammonia in OH/IR supergiants

    Science.gov (United States)

    Mclaren, R. A.; Betz, A. L.

    1980-01-01

    Ammonia has been detected in the circumstellar envelopes of VY Canis Majoris, VX Sagittarii, and IRC +10420 by means of several absorption lines in the nu-2 vibration-rotation band near 950 kaysers. The line profiles are well resolved (0.2 km/sec resolution) and show the gas being accelerated to terminal expansion velocities near 30 km/sec. The observations reveal a method for determining the position of the central star on VLBI maps of OH maser emission to an accuracy of approximately 0.2 arcsec. A firm lower limit of 2 x 10 to the 15th/sq cm is obtained for the NH3 column density in VY Canis Majoris.

  5. Infrared observations of circumstellar ammonia in OH/IR supergiants

    International Nuclear Information System (INIS)

    McLaren, R.A.; Betz, A.L.

    1980-01-01

    Ammonia has been detected in the circumstellar envelopes of VY Canis Majoris, VX Sagittarii, and IRC+10420 by means of several absorption lines in the ν 2 vibration-rotation band near 950 cm -1 . The line profiles are well resolved (0.2 km s -1 resolution) and show the gas being accelerated to terminal expansion velocities near 30 km s -1 . The observations reveal a method for determining the position of the central star on VLBI maps of OH maser emission to an accuracy of approx.0''.2. A firm lower limit of 2 x 10 15 cm -2 is obtained for the NH 3 column density in VY Canis Majoris

  6. Colloidal Engineering for Infrared-Bandgap Solution-Processed Quantum Dot Solar Cells

    Science.gov (United States)

    Kiani, Amirreza

    Ever-increasing global energy demand and a diminishing fossil fuel supply have prompted the development of technologies for sustainable energy production. Solar photovoltaic (PV) devices have huge potential for energy harvesting and production since the sun delivers more energy to the earth in one hour than the global population consumes in one year. The solar cell industry is now dominated by silicon PV devices. The cost of silicon modules has decreased substantially over the past two decades and the number of installed silicon PV devices has increased dramatically. There remains a need for emerging solar technologies that can harvest the untapped portion of the solar spectrum and can be integrated on flexible and curved surfaces. This thesis focuses on colloidal quantum dot (CQD) PV devices. CQDs are nanoparticles fabricated using a low-temperature and cost-effective solution technique. These materials suffer from a high density of surface traps derived from the large surface-to-volume ratio of CQD nanoparticles, combined with limited carrier mobility. These result in a short carrier diffusion length, a main limiting factor in CQD solar cell performance. This thesis seeks to address the poor diffusion length in lead sulfide (PbS) CQD films and pave the way for new applications for CQD PV devices in infrared solar harvesting and waste heat recovery. A two-fold reduction in surface trap density is demonstrated using molecular halide treatment. Iodine molecules introduced prior to the film formation replace the otherwise unpassivated surface sulfur atoms. This results in a 35% increase in the diffusion length and enables charge extraction over thicker active layer leading to the world's most efficient CQD PV devices from June 2015 to July 2016 with the certified power conversion efficiency of 9.9%. This represents a 30% increase over the best-certified PCE (7.5%) prior to this thesis. The colloidal engineering highlighted herein enables infrared (IR) solar

  7. Observation of solar gamma-ray by Hinotori

    International Nuclear Information System (INIS)

    Yoshimori, Masato; Okudaira, Kiyoaki; Hirashima, Yo; Kondo, Ichiro.

    1982-01-01

    The solar gamma-ray emitted by solar flare was observed. The gamma-ray is the electromagnetic radiation with the energy more than 300 keV. The line gamma-ray intensity and the time profile were observed. The gamma-ray detector CsI (Tl) was loaded on Hinotori, and the observed gamma-ray was analyzed by a multi-channel analyzer. The observed line gamma-ray was the radiation from Fe-56 and Ne-20. The line gamma-ray from C-12 and O-16 was also seen. These gamma-ray is the direct evidence of the nuclear reaction on the sun. The observed spectrum suggested the existence of the lines from Mg-24 and Si-28. The intensity of the 2.22 MeV gamma-line was small. This fact showed that the origin of this line was different from other nuclear gamma-ray. Two kinds of hard X-ray bursts were detected. The one was impulsive burst, and the other was gradual burst. There was no time difference between the hard X-ray and the gamma-ray of the impulsive burst. The impulsive burst may be explained by the beam model. The delay of time profile in the high energy gamma-ray of the gradual burst was observed. This means that the time when accelerated electrons cause bremsstrahlung depends on the electron energy. The long trapping of electrons at the top of magnetic loop is suggested. (Kato, T.)

  8. The Trojan-Hilda-KBO connection: An observational test of solar system evolution models

    Science.gov (United States)

    Wong, I.; Brown, M. E.

    2017-12-01

    Over the past few decades, many theories have been devised to explain the observed solar system architecture. The current paradigm posits that a significant reorganization of the outer Solar System occurred after the end of planet formation. Specifically, it is hypothesized that Jupiter and Saturn crossed a mutual mean motion resonance, leading to a chaotic expansion of the ice giants' orbits that disrupted the large population of planetesimals situated further out. While the majority of these bodies were ejected from the Solar System, a fraction of them were retained as the present-day Kuiper Belt, while others were scattered inward and captured into resonances with Jupiter to become the Trojans and Hildas. Dynamical instability models invariably predict that Trojans, Hildas, and Kuiper Belt objects (KBOs) were sourced from the same primordial body of outer solar system planetesimals. Therefore, comparison of these minor body populations serves as one of the few available observational tests of our present understanding of solar system evolution. We present the results of a series of studies aimed at synthesizing a detailed picture of Trojans and related asteroid populations. By combining analyses of archival data with new photometric surveys, we have derived the first debiased color distributions of Trojans and KBOs and extended/refined our knowledge of their respective size distributions. In addition, we have explored the peculiar color bimodality attested in the Trojans, Hildas, and KBOs, which indicates the presence of two sub-populations. As part of our continuing efforts to characterize the surface composition of these bodies, we have also obtained new near-infrared spectra of Hildas for comparison with previously published spectra of Trojans covering the same wavelength region. We have utilized the full body of observations to formulate hypotheses regarding the formation, composition, and dynamical/chemical evolution of the primordial outer solar system

  9. Periodicities observed on solar flux index (F10.7) during geomagnetic disturbances

    Science.gov (United States)

    Adhikari, B.; Narayan, C.; Chhatkuli, D. N.

    2017-12-01

    Solar activities change within the period of 11 years. Sometimes the greatest event occurs in the period of solar maxima and the lowest activity occurs in the period of solar minimum. During the time period of solar activity sunspots number will vary. A 10.7 cm solar flux measurement is a determination of the strength of solar radio emission. The solar flux index is more often used for the prediction and monitoring of the solar activity. This study mainly focused on the variation on solar flux index and amount of electromagnetic wave in the atmosphere. Both seasonal and yearly variation on solar F10.7 index. We also analyzed the dataset obatained from riometer.Both instruments show seasonal and yearly variations. We also observed the solar cycle dependence on solar flux index and found a strong dependence on solar activity. Results also show that solar intensities higher during the rising phase of solar cycle. We also observed periodicities on solar flux index using wavelet analysis. Through this analysis, it was found that the power intensities of solar flux index show a high spectral variability.

  10. Estimation of solar radiation from Australian meterological observations

    International Nuclear Information System (INIS)

    Moriarty, W.W.

    1991-01-01

    A carefully prepared set of Australian radiation and meteorological data was used to develop a system for estimating hourly or instantaneous broad band direct, diffuse and global radiation from meteorological observations. For clear sky conditions relationships developed elsewhere were adapted to Australian data. For cloudy conditions the clouds were divided into two groups, high clouds and opaque (middle and low) clouds, and corrections were made to compensate for the bias due to reporting practices for almost clear and almost overcast skies. Careful consideration was given to the decrease of visible sky toward the horizon caused by the vertical extent of opaque clouds. Equations relating cloud and other meteorological observations to the direct and diffuse radiation contained four unknown quantities, functions of cloud amount and of solar elevation, which were estimated from the data. These were the proportions of incident solar radiation passed on as direct and as diffuse radiation by high clouds, and as diffuse radiation by opaque clouds, and a factor to describe the elevation dependence of the fraction of sky not obscured by opaque clouds. When the resulting relationships were used to estimate global, direct and diffuse radiation on a horizontal surface, the results were good, especially for global radiation. Some discrepancies between estimates and measurements of diffuse and direct radiation were probably due to erroneously high measurements of diffuse radiation

  11. THE THERMAL PROPERTIES OF SOLAR FLARES OVER THREE SOLAR CYCLES USING GOES X-RAY OBSERVATIONS

    International Nuclear Information System (INIS)

    Ryan, Daniel F.; Gallagher, Peter T.; Milligan, Ryan O.; Dennis, Brian R.; Kim Tolbert, A.; Schwartz, Richard A.; Alex Young, C.

    2012-01-01

    Solar flare X-ray emission results from rapidly increasing temperatures and emission measures in flaring active region loops. To date, observations from the X-Ray Sensor (XRS) on board the Geostationary Operational Environmental Satellite (GOES) have been used to derive these properties, but have been limited by a number of factors, including the lack of a consistent background subtraction method capable of being automatically applied to large numbers of flares. In this paper, we describe an automated Temperature and Emission measure-Based Background Subtraction method (TEBBS), that builds on the methods of Bornmann. Our algorithm ensures that the derived temperature is always greater than the instrumental limit and the pre-flare background temperature, and that the temperature and emission measure are increasing during the flare rise phase. Additionally, TEBBS utilizes the improved estimates of GOES temperatures and emission measures from White et al. TEBBS was successfully applied to over 50,000 solar flares occurring over nearly three solar cycles (1980-2007), and used to create an extensive catalog of the solar flare thermal properties. We confirm that the peak emission measure and total radiative losses scale with background subtracted GOES X-ray flux as power laws, while the peak temperature scales logarithmically. As expected, the peak emission measure shows an increasing trend with peak temperature, although the total radiative losses do not. While these results are comparable to previous studies, we find that flares of a given GOES class have lower peak temperatures and higher peak emission measures than previously reported. The TEBBS database of flare thermal plasma properties is publicly available at http://www.SolarMonitor.org/TEBBS/.

  12. Statistics of counter-streaming solar wind suprathermal electrons at solar minimum: STEREO observations

    Directory of Open Access Journals (Sweden)

    B. Lavraud

    2010-01-01

    Full Text Available Previous work has shown that solar wind suprathermal electrons can display a number of features in terms of their anisotropy. Of importance is the occurrence of counter-streaming electron patterns, i.e., with "beams" both parallel and anti-parallel to the local magnetic field, which is believed to shed light on the heliospheric magnetic field topology. In the present study, we use STEREO data to obtain the statistical properties of counter-streaming suprathermal electrons (CSEs in the vicinity of corotating interaction regions (CIRs during the period March–December 2007. Because this period corresponds to a minimum of solar activity, the results are unrelated to the sampling of large-scale coronal mass ejections, which can lead to CSE owing to their closed magnetic field topology. The present study statistically confirms that CSEs are primarily the result of suprathermal electron leakage from the compressed CIR into the upstream regions with the combined occurrence of halo depletion at 90° pitch angle. The occurrence rate of CSE is found to be about 15–20% on average during the period analyzed (depending on the criteria used, but superposed epoch analysis demonstrates that CSEs are preferentially observed both before and after the passage of the stream interface (with peak occurrence rate >35% in the trailing high speed stream, as well as both inside and outside CIRs. The results quantitatively show that CSEs are common in the solar wind during solar minimum, but yet they suggest that such distributions would be much more common if pitch angle scattering were absent. We further argue that (1 the formation of shocks contributes to the occurrence of enhanced counter-streaming sunward-directed fluxes, but does not appear to be a necessary condition, and (2 that the presence of small-scale transients with closed-field topologies likely also contributes to the occurrence of counter-streaming patterns, but only in the slow solar wind prior to

  13. The James Webb Space Telescope's Plan for Operations and Instrument Capabilities for Observations in the Solar System

    Science.gov (United States)

    Milam, Stefanie N.; Stansberry, John A.; Sonneborn, George; Thomas, Cristina

    2016-01-01

    The James Webb Space Telescope (JWST) is optimized for observations in the near- and mid-infrared and will provide essential observations for targets that cannot be conducted from the ground or other missions during its lifetime. The state-of-the-art science instruments, along with the telescope's moving target tracking, will enable the infrared study, with unprecedented detail, for nearly every object (Mars and beyond) in the Solar System. The goals of this special issue are to stimulate discussion and encourage participation in JWST planning among members of the planetary science community. Key science goals for various targets, observing capabilities for JWST, and highlights for the complementary nature with other missions/observatories are described in this paper.

  14. An empirical line-by-line model for the infrared solar transmittance spectrum from 700 to 5000cm{sup -1}

    Energy Technology Data Exchange (ETDEWEB)

    Hase, F. [Institut fuer Meteorologie und Klimaforschung, Forschungszentrum Karlsruhe, Postfach 3640, D-76021 Karlsruhe (Germany)]. E-mail: frank.hase@imk.fzk.de; Demoulin, P. [Institut d' Astrophysique et de Geophysique, allee du VI aout, 17, batiment B5a, B-4000, Liege (Belgium); Sauval, A.J. [Observatoire Royal de Belgique, avenue circulaire, 3, B-1180, Bruxelles (Belgium); Toon, G.C. [Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Bernath, P.F. [Department of Chemistry, University of Waterloo, Waterloo, Ont., Canada N2L3G1 (Canada); Goldman, A. [Department of Physics, University of Denver, Denver, CO 80208 (United States); Hannigan, J.W. [Atmospheric Chemistry Division, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80303 (United States); Rinsland, C.P. [NASA Langley Research Center, Hampton, VA 23681-2199 (United States)

    2006-12-15

    An empirical line-by-line model for the infrared solar transmittance spectrum is presented. The model can be incorporated into radiative transfer codes to allow fast calculation of all relevant emission and absorption features in the solar spectrum in the mid-infrared region from 700 to 5000cm{sup -1}. The transmittance is modelled as a function of the diameter of the field-of-view centered on the solar disk: the line broadening due to solar rotation as well as center-to-limb variations in strength and width are taken into account for stronger lines. Applications of the model presented here are in the fields of terrestrial remote sensing in the mid-infrared spectral region when the sun is used as radiation source or scattered solar radiation contributes to the measured signal and in the fields of atmospheric radiative transfer algorithms which compute the propagation of infrared solar radiation in the terrestrial atmosphere.

  15. Titan's Surface Composition from Cassini VIMS Solar Occultation Observations

    Science.gov (United States)

    McCord, Thomas; Hayne, Paul; Sotin, Christophe

    2013-04-01

    Titan's surface is obscured by a thick absorbing and scattering atmosphere, allowing direct observation of the surface within only a few spectral win-dows in the near-infrared, complicating efforts to identify and map geologi-cally important materials using remote sensing IR spectroscopy. We there-fore investigate the atmosphere's infrared transmission with direct measure-ments using Titan's occultation of the Sun as well as Titan's reflectance measured at differing illumination and observation angles observed by Cas-sini's Visual and Infrared Mapping Spectrometer (VIMS). We use two im-portant spectral windows: the 2.7-2.8-mm "double window" and the broad 5-mm window. By estimating atmospheric attenuation within these windows, we seek an empirical correction factor that can be applied to VIMS meas-urements to estimate the true surface reflectance and map inferred composi-tional variations. Applying the empirical corrections, we correct the VIMS data for the viewing geometry-dependent atmospheric effects to derive the 5-µm reflectance and 2.8/2.7-µm reflectance ratio. We then compare the cor-rected reflectances to compounds proposed to exist on Titan's surface. We propose a simple correction to VIMS Titan data to account for atmospheric attenuation and diffuse scattering in the 5-mm and 2.7-2.8 mm windows, generally applicable for airmass water ice for the majority of the low-to-mid latitude area covered by VIMS measurements. Four compositional units are defined and mapped on Titan's surface based on the positions of data clusters in 5-mm vs. 2.8/2.7-mm scatter plots; a simple ternary mixture of H2O, hydrocarbons and CO2 might explain the reflectance properties of these surface units. The vast equatorial "dune seas" are compositionally very homogeneous, perhaps suggesting transport and mixing of particles over very large distances and/or and very consistent formation process and source material. The composi-tional branch characterizing Tui Regio and Hotei Regio is

  16. Solar minimum Lyman alpha sky background observations from Pioneer Venus orbiter ultraviolet spectrometer - Solar wind latitude variation

    Science.gov (United States)

    Ajello, J. M.

    1990-01-01

    Measurements of interplanetary H I Lyman alpha over a large portion of the celestial sphere were made at the recent solar minimum by the Pioneer Venus orbiter ultraviolet spectrometer. These measurements were performed during a series of spacecraft maneuvers conducted to observe Halley's comet in early 1986. Analysis of these data using a model of the passage of interstellar wind hydrogen through the solar system shows that the rate of charge exchange with solar wind protons is 30 percent less over the solar poles than in the ecliptic. This result is in agreement with a similar experiment performed with Mariner 10 at the previous solar minimum.

  17. Hard X-Ray Emission from Partially Occulted Solar Flares: RHESSI Observations in Two Solar Cycles

    Energy Technology Data Exchange (ETDEWEB)

    Effenberger, Frederic; Costa, Fatima Rubio da; Petrosian, Vahé [Department of Physics and KIPAC, Stanford University, Stanford, CA 94305 (United States); Oka, Mitsuo; Saint-Hilaire, Pascal; Krucker, Säm [Space Sciences Laboratory, University of California, Berkeley, CA 94720-7450 (United States); Liu, Wei [Bay Area Environmental Research Institute, 625 2nd Street, Suite 209, Petaluma, CA 94952 (United States); Glesener, Lindsay, E-mail: feffen@stanford.edu, E-mail: frubio@stanford.edu [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States)

    2017-02-01

    Flares close to the solar limb, where the footpoints are occulted, can reveal the spectrum and structure of the coronal looptop source in X-rays. We aim at studying the properties of the corresponding energetic electrons near their acceleration site, without footpoint contamination. To this end, a statistical study of partially occulted flares observed with Reuven Ramaty High-Energy Solar Spectroscopic Imager is presented here, covering a large part of solar cycles 23 and 24. We perform detailed spectra, imaging, and light curve analyses for 116 flares and include contextual observations from SDO and STEREO when available, providing further insights into flare emission that were previously not accessible. We find that most spectra are fitted well with a thermal component plus a broken power-law, non-thermal component. A thin-target kappa distribution model gives satisfactory fits after the addition of a thermal component. X-ray imaging reveals small spatial separation between the thermal and non-thermal components, except for a few flares with a richer coronal source structure. A comprehensive light curve analysis shows a very good correlation between the derivative of the soft X-ray flux (from GOES ) and the hard X-rays for a substantial number of flares, indicative of the Neupert effect. The results confirm that non-thermal particles are accelerated in the corona and estimated timescales support the validity of a thin-target scenario with similar magnitudes of thermal and non-thermal energy fluxes.

  18. Solar thermal and concentrated solar power barometer - EurObserv'ER - May 2011

    International Nuclear Information System (INIS)

    2011-05-01

    638,4 MWe The CSP plant electrical generating capacity in the EU at the end of 2010 As could be expected, the recession cast long shadows over the European solar thermal market throughout 2010. For the second year running, new installations for hot water production and space heating (collectors) decreased. According to the EurObserv'ER survey the newly-assigned surface area was 3.8 million m2 in 2010, down from 4.2 million m2 in 2009 and 4.6 million m2 in 2008. At the same time, the European high-temperature solar sector related to electricity production has been taking shape alongside the heat-producing applications, with 638.4 MW already installed. Spain accounts for almost all of this capacity, and a further five EU countries, mostly Mediterranean, intend to develop the sector

  19. Solar thermal and concentrated solar power barometer - EurObserv'ER - May 2014

    International Nuclear Information System (INIS)

    2014-05-01

    The European concentrated solar plant market is set to mark time for a year following efforts to complete construction on 350 MW of CSP capacity in Spain in 2013. The spotlight has switched to Italy which could re-launch the European market within a couple of years. The European solar thermal market for heat and hot water production and space heating, is shrinking all the time. EurObserv'ER reports that the market is in its fifth successive year of contraction in the European Union. It now posts a 10.5% decline on its 2012 performance having struggled to install just over 3 million m 2 of collectors in 2013

  20. Enhanced sensitivity to near-infrared with high fill factor in small molecular organic solar cells

    Science.gov (United States)

    Shim, Hyun-Sub; Kim, Hyo Jung; Kim, Ji Whan; Kim, Sei-Yong; Jeong, Won-Ik; Kim, Tae-Min; Kim, Jang-Joo

    2012-09-01

    High efficiency near-infrared (NIR) absorbing solar cells based on lead phthalocyanine (PbPc) are reported using copper iodide (CuI) as a templating layer to control the crystal structure of PbPc. Devices with CuI inserted between the ITO and PbPc layers exhibit a two times enhancement of the JSC compared to the case in the absence of the CuI layer. This is due to the increase of crystallinity in the molecules grown on the CuI templating layer, which is investigated via an x-ray diffraction study. Moreover, fill factor is also enhanced to 0.63 from 0.57 due to low series resistance although the additional CuI layer is inserted between the ITO and the PbPc layer. As a result, the corrected power conversion efficiency of 2.5% was obtained, which is the highest one reported up to now among the PbPc based solar cells.

  1. Aperture synthesis observations of solar and stellar radio emission

    International Nuclear Information System (INIS)

    Bastian, T.S.

    1987-01-01

    The work presented in this thesis relied upon the radio astronomical instrument, The Very Large Array. The thesis is divided into three major sections. In the first the author applied maximum entropy-type image reconstruction techniques, using both single dish and iterferometer data, to generate full disk images of the Sun at a wavelength λ ∼ 21 cm. Using a set of six such images obtained during the Sun's decline from sunspot maximum to minimum, he has noted a number of previously unreported phenomena. Among these: (1) a systematic decrease in quiet Sun's brightness temperature as it declined to minimum; (2) a systematic decrease in the Sun's radius at 21 cm; (3) evidence for the evolution of polar coronal holes during the course of the solar cycle. The observed variation, though not noted previously at radio wavelengths, is entirely consistent with white light K coronagraph data. The results reported here explain the conflicting nature of a number of past observations. In the second section of the thesis, he presents the results of a long term survey of magnetic cataclysmic variables (CVs). Cataclysmic variables are close binary systems which contain a white dwarf accreting mass from a late-type secondary, typically a dwarf of spectral type, G, K, or M. The survey resulted in the detection of two out of the eighteen systems observed. In the third section of the thesis, he presents new results on flare stars in the solar neighborhood and in the Pleiades. He has successfully employed the technique of dynamic spectroscopy to constrain the mechanisms(s) for radio flaring on other stars. The second part of section three is devoted to a search for radio emission from flare stars in the Pleiades which was motivated by the evolutionary questions raised by flare stars and the Pleiades lower main sequence

  2. High-resolution far-infrared observations of the galactic center

    International Nuclear Information System (INIS)

    Harvey, P.M.; Campbell, M.F.; Hoffmann, W.F.

    1976-01-01

    A map at 53 μ with 17'' resolution and three-color observations at 53 μ, 100 μ, and 175 μ with approx.30'' beams of Sgr A are presented. Sagittarius A is resolved into two main sources, one associated with the cluster of strong 10 μ sources and another approx.45'' to the southwest coincident with a weak 10 μ source. The dust temperature peaks near the strong 10 μ sources, but the 100 μ and 175 μ fluxes and the far-infrared optical depth are greatest near the southwest source. The amount of dust required to explain the far-infrared emission is comparable to that observed in absorption in the near-infrared

  3. Instrument Design of the Large Aperture Solar UV Visible and IR Observing Telescope (SUVIT) for the SOLAR-C Mission

    Science.gov (United States)

    Suematsu, Y.; Katsukawa, Y.; Shimizu, T.; Ichimoto, K.; Takeyama, N.

    2012-12-01

    We present an instrumental design of one major solar observation payload planned for the SOLAR-C mission: the Solar Ultra-violet Visible and near IR observing Telescope (SUVIT). The SUVIT is designed to provide high-angular-resolution investigation of the lower solar atmosphere, from the photosphere to the uppermost chromosphere, with enhanced spectroscopic and spectro-polarimetric capability in wide wavelength regions from 280 nm (Mg II h&k lines) to 1100 nm (He I 1083 nm line) with 1.5 m class aperture and filtergraphic and spectrographic instruments.

  4. Observations of Infrared Radiative Cooling in the Thermosphere on Daily to Multiyear Timescales from the TIMED/SABER Instrument

    Science.gov (United States)

    Mlynczak, Martin G.; Hunt, Linda A.; Marshall, B. Thomas; Martin-Torres, F. Javier; Mertens, Christopher J.; Russell, James M., III; Remsberg, Ellis E.; Lopez-Puertas, Manuel; Picard, Richard; Winick, Jeremy; hide

    2009-01-01

    We present observations of the infrared radiative cooling by carbon dioxide (CO2) and nitric oxide (NO) in Earth s thermosphere. These data have been taken over a period of 7 years by the SABER instrument on the NASA TIMED satellite and are the dominant radiative cooling mechanisms for the thermosphere. From the SABER observations we derive vertical profiles of radiative cooling rates (W/cu m), radiative fluxes (W/sq m), and radiated power (W). In the period from January 2002 through January 2009 we observe a large decrease in the cooling rates, fluxes, and power consistent with the declining phase of solar cycle. The power radiated by NO during 2008 when the Sun exhibited few sunspots was nearly one order of magnitude smaller than the peak power observed shortly after the mission began. Substantial short-term variability in the infrared emissions is also observed throughout the entire mission duration. Radiative cooling rates and radiative fluxes from NO exhibit fundamentally different latitude dependence than do those from CO2, with the NO fluxes and cooling rates being largest at high latitudes and polar regions. The cooling rates are shown to be derived relatively independent of the collisional and radiative processes that drive the departure from local thermodynamic equilibrium (LTE) in the CO2 15 m and the NO 5.3 m vibration-rotation bands. The observed NO and CO2 cooling rates have been compiled into a separate dataset and represent a climate data record that is available for use in assessments of radiative cooling in upper atmosphere general circulation models.

  5. ISO observations of far-infrared rotational emission lines of water vapor toward the supergiant star VY Canis Majoris

    OpenAIRE

    Neufeld, David A.; Feuchtgruber, Helmut; Harwit, Martin; Melnick, Gary J.

    1999-01-01

    We report the detection of numerous far-infrared emission lines of water vapor toward the supergiant star VY Canis Majoris. A 29.5 - 45 micron grating scan of VY CMa, obtained using the Short Wavelength Spectrometer (SWS) of the Infrared Space Observatory (ISO) at a spectral resolving power of approximately 2000, reveals at least 41 spectral features due to water vapor that together radiate a total luminosity ~ 25 solar luminosities. In addition to pure rotational transitions within the groun...

  6. Clementine Observes the Moon, Solar Corona, and Venus

    Science.gov (United States)

    1997-01-01

    In 1994, during its flight, the Clementine spacecraft returned images of the Moon. In addition to the geologic mapping cameras, the Clementine spacecraft also carried two Star Tracker cameras for navigation. These lightweight (0.3 kg) cameras kept the spacecraft on track by constantly observing the positions of stars, reminiscent of the age-old seafaring tradition of sextant/star navigation. These navigation cameras were also to take some spectacular wide angle images of the Moon.In this picture the Moon is seen illuminated solely by light reflected from the Earth--Earthshine! The bright glow on the lunar horizon is caused by light from the solar corona; the sun is just behind the lunar limb. Caught in this image is the planet Venus at the top of the frame.

  7. Submillimeter and millimeter observations of solar system objects

    International Nuclear Information System (INIS)

    Muhleman, D.O.

    1988-01-01

    Planetary atmospheres and satellite surfaces are observed with the three element array at Caltech's Owens Valley Radio Observatory, Caltech's submillimeter telescope on Mauna Kea and at the 12-meter telescope at Kitt Peak. Researchers are primarily interested in spectroscopy of the atmospheres of Venus, Mars and Titan and the continuum structure of Saturn Rings, Galilean satellites, Neptune and Uranus. During the last year researchers completed a supersynthesis of the Saturn system at 2.8 mm with spatial resolution of 3 arc sec. They just completed a 4-confuguration synthesis of Venus in the CO absorption line. They hope to recover the wind patterns in the altitude range from 60 to 100 km where winds have never been measured. Two important questions are being investigated: (1) how high in the Venus atmosphere do 4-day winds extend, and (2) can we produce experiment proof (or disproof) of the subsolar-to-anti-solar flow (Dickenson winds) predicted by general circulation models

  8. NEW SOLAR EXTREME-ULTRAVIOLET IRRADIANCE OBSERVATIONS DURING FLARES

    International Nuclear Information System (INIS)

    Woods, Thomas N.; Hock, Rachel; Eparvier, Frank; Jones, Andrew R.; Chamberlin, Phillip C.; Klimchuk, James A.; Didkovsky, Leonid; Judge, Darrell; Mariska, John; Warren, Harry; Schrijver, Carolus J.; Webb, David F.; Bailey, Scott; Tobiska, W. Kent

    2011-01-01

    New solar extreme-ultraviolet (EUV) irradiance observations from the NASA Solar Dynamics Observatory (SDO) EUV Variability Experiment provide full coverage in the EUV range from 0.1 to 106 nm and continuously at a cadence of 10 s for spectra at 0.1 nm resolution and even faster, 0.25 s, for six EUV bands. These observations can be decomposed into four distinct characteristics during flares. First, the emissions that dominate during the flare's impulsive phase are the transition region emissions, such as the He II 30.4 nm. Second, the hot coronal emissions above 5 MK dominate during the gradual phase and are highly correlated with the GOES X-ray. A third flare characteristic in the EUV is coronal dimming, seen best in the cool corona, such as the Fe IX 17.1 nm. As the post-flare loops reconnect and cool, many of the EUV coronal emissions peak a few minutes after the GOES X-ray peak. One interesting variation of the post-eruptive loop reconnection is that warm coronal emissions (e.g., Fe XVI 33.5 nm) sometimes exhibit a second large peak separated from the primary flare event by many minutes to hours, with EUV emission originating not from the original flare site and its immediate vicinity, but rather from a volume of higher loops. We refer to this second peak as the EUV late phase. The characterization of many flares during the SDO mission is provided, including quantification of the spectral irradiance from the EUV late phase that cannot be inferred from GOES X-ray diagnostics.

  9. Interstellar Explorer Observations of the Solar System's Debris Disks

    Science.gov (United States)

    Lisse, C. M.; McNutt, R. L., Jr.; Brandt, P. C.

    2017-12-01

    Planetesimal belts and debris disks full of dust are known as the "signposts of planet formation" in exosystems. The overall brightness of a disk provides information on the amount of sourcing planetesimal material, while asymmetries in the shape of the disk can be used to search for perturbing planets. The solar system is known to house two such belts, the Asteroid belt and the Kuiper Belt; and at least one debris cloud, the Zodiacal Cloud, sourced by planetisimal collisions and Kuiper Belt comet evaporative sublimation. However these are poorly understood in toto because we live inside of them. E.g., while we know of the two planetesimal belt systems, it is not clear how much, if any, dust is produced from the Kuiper belt since the near-Sun comet contributions dominate near-Earth space. Understanding how much dust is produced in the Kuiper belt would give us a much better idea of the total number of bodies in the belt, especially the smallest ones, and their dynamical collisional state. Even for the close in Zodiacal cloud, questions remain concerning its overall shape and orientation with respect to the ecliptic and invariable planes of the solar system - they aren't explainable from the perturbations caused by the known planets alone. In this paper we explore the possibilities of using an Interstellar Explorer telescope placed at 200 AU from the sun to observe the brightness, shape, and extent of the solar system's debris disk(s). We should be able to measure the entire extent of the inner, near-earth zodiacal cloud; whether it connects smoothly into an outer cloud, or if there is a second outer cloud sourced by the Kuiper belt and isolated by the outer planets, as predicted by Stark & Kuchner (2009, 2010) and Poppe et al. (2012, 2016; Figure 1). VISNIR imagery will inform about the dust cloud's density, while MIR cameras will provide thermal imaging photometry related to the cloud's dust particle size and composition. Observing at high phase angle by looking

  10. One-Year Observations of Jupiter by the Jovian Infrared Auroral Mapper on Juno

    Science.gov (United States)

    Adriani, A.; Mura, A.; Bolton, S. J.; Connerney, J. E. P.; Levin, S.; Becker, H. N.; Bagenal, F.; Hansen, C. J.; Orton, G.; Gladstone, R.; Kurth, W. S.; Mauk, B.; Valek, P. W.

    2017-12-01

    The Jovian InfraRed Auroral Mapper (JIRAM) [1] on board the Juno [2,3] spacecraft, is equipped with an infrared camera and a spectrometer working in the spectral range 2-5 μm. JIRAM was built to study the infrared aurora of Jupiter as well as to map the planet's atmosphere in the 5 µm spectral region. The spectroscopic observations are used for studying clouds and measuring the abundance of some chemical species that have importance in the atmosphere's chemistry, microphysics and dynamics like water, ammonia and phosphine. During 2017 the instrument will operate during all 7 of Juno's Jupiter flybys. JIRAM has performed several observations of the polar regions of the planet addressing the aurora and the atmosphere. Unprecedented views of the aurora and the polar atmospheric structures have been obtained. We present a survey of the most significant observations that the instrument has performed during the current year. [1] Adriani A. et al., JIRAM, the Jovian Infrared Auroral Mapper. Space Sci. Rew., DOI 10.1007/s11214-014-0094-y, 2014. [2] Bolton S.J. et al., Jupiter's interior and deep atmosphere: The initial pole-to-pole passes with the Juno spacecraft. Science DOI: 10.1126/science.aal2108, 2017. [3] Connerney J. E.P. et al., Jupiter's magnetosphere and aurorae observed by the Juno spacecraft during its first polar orbits. Science, DOI: 10.1126/science.aam5928, 2017.

  11. Synchronous photoelectrical observations of flare stars in the visible and near infrared ranges

    International Nuclear Information System (INIS)

    Bruevich, V.V.; Kilyachkov, N.N.; Shevchenko, V.S.; Burnashov, V.I.; Grinin, V.P.; Koryshev, V.V.; Shakhovskaya, N.I.

    1980-01-01

    The results of synchronous photoelectrical observations of the AD Leo and EV Lac flare stars made in 1975 in the Crimea in B-filter and in the near infrared region (i-band, lambdasub(ef) approximately 0.85 μm) and the observations of the UV Cet and EV Lac stars made in 1976 in the Astronomical Institute Uzbek SSR in three passbands: U, isub(TiO)(lambdasub(ef)=0.71 μ) and isub(C)(lambdasub(ef)=0.80μm) are given. Practically all strong flares in the visible spectral range were followed by the IR-flares. In about 70% of the cases the predicted infrared negative preflares were observed. The amplitudes (in erg/s) of the negative flares are comparable with the amplitude of the optical flares. The analysis of the observed data shows that: a) the amplitudes and the energies of the positive IR flares are in average the larger the stronger is the optical flare; b) the amplitudes of the negative IR preflares are on the contrary the smaller the stronger is the optical flare; c) there are infrared flares the main energy out of which takes place in the infrared range of wavelengths; d) The U-i color shows a positive correlation with the amplitude of the flare in U: the stronger is the flare the bluer is its radiation

  12. Statistical retrieval of thin liquid cloud microphysical properties using ground-based infrared and microwave observations

    Science.gov (United States)

    Marke, Tobias; Ebell, Kerstin; Löhnert, Ulrich; Turner, David D.

    2016-12-01

    In this article, liquid water cloud microphysical properties are retrieved by a combination of microwave and infrared ground-based observations. Clouds containing liquid water are frequently occurring in most climate regimes and play a significant role in terms of interaction with radiation. Small perturbations in the amount of liquid water contained in the cloud can cause large variations in the radiative fluxes. This effect is enhanced for thin clouds (liquid water path, LWP cloud properties crucial. Due to large relative errors in retrieving low LWP values from observations in the microwave domain and a high sensitivity for infrared methods when the LWP is low, a synergistic retrieval based on a neural network approach is built to estimate both LWP and cloud effective radius (reff). These statistical retrievals can be applied without high computational demand but imply constraints like prior information on cloud phase and cloud layering. The neural network retrievals are able to retrieve LWP and reff for thin clouds with a mean relative error of 9% and 17%, respectively. This is demonstrated using synthetic observations of a microwave radiometer (MWR) and a spectrally highly resolved infrared interferometer. The accuracy and robustness of the synergistic retrievals is confirmed by a low bias in a radiative closure study for the downwelling shortwave flux, even for marginally invalid scenes. Also, broadband infrared radiance observations, in combination with the MWR, have the potential to retrieve LWP with a higher accuracy than a MWR-only retrieval.

  13. Global Distribution and Variations of NO Infrared Radiative Flux and Its Responses to Solar Activity and Geomagnetic Activity in the Thermosphere

    Science.gov (United States)

    Tang, Chaoli; Wei, Yuanyuan; Liu, Dong; Luo, Tao; Dai, Congming; Wei, Heli

    2017-12-01

    The global distribution and variations of NO infrared radiative flux (NO-IRF) are presented during 2002-2016 in the thermosphere covering 100-280 km altitude based on Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) data set. For investigating the spatial variations of the mutual relationship between NO-IRF and solar activity, the altitude ranges from 100 km to 280 km are divided into 90 altitude bins, and the latitude regions of 83°S-83°N are divided into 16 latitude bins. By processing about 1.8E9 NO-IRF observation values from about 5E6 vertical nighttime profiles recorded in SABER data set, we obtained more than 4.1E8 samples of NO-IRF. The annual-mean values of NO-IRF are then calculated by all available NO-IRF samples within each latitude and altitude bin. Local latitudinal maxima in NO-IRF are found between 120 and 145 km altitude, and the maximum NO-IRF located at polar regions are 3 times more than that of the minimum at equatorial region. The influences of solar and geomagnetic activity on the spatial variations of NO-IRF are investigated. Both the NO-IRF and its response to solar and geomagnetic activity show nearly symmetric distribution between the two hemispheres. It is demonstrated that the observed changes in NO-IRF at altitudes between 100 and 225 km correlate well with the changes in solar activity. The NO-IRF at solar maximum is about 4 times than that at solar minimum, and the current maximum of NO-IRF in 2014 is less than 70% of the prior maximum in 2001. For the first time, the response ranges of the NO-IRF to solar and geomagnetic activity at different altitudes and latitudes are reported.

  14. Infrared

    Science.gov (United States)

    Vollmer, M.

    2013-11-01

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

  15. Infrared observations and mass loss of the binary system V861 Sco

    International Nuclear Information System (INIS)

    Tanzi, E.G.; Maraschi, L.; Tarenghi, M.; Treves, A.

    1981-01-01

    V 861 Sco (HD 152667) is a well known single line binary. The proposed association with a variable X-ray source has triggered renewed interest in the system. Here the authors report on a series of photometric observations in the infrared (from 1.25 to 4.8 μ) taken at various orbital phases which improve and extend previous measurements by Tanzi et al. The results give evidence of a phase modulated infrared excess which can be interpreted in terms of a non isotropic mass flow in the system or, alternately, of a contribution from a colder secondary component. (Auth.)

  16. HEMISPHERIC ASYMMETRIES IN THE POLAR SOLAR WIND OBSERVED BY ULYSSES NEAR THE MINIMA OF SOLAR CYCLES 22 AND 23

    Energy Technology Data Exchange (ETDEWEB)

    Ebert, R. W.; Dayeh, M. A.; Desai, M. I.; McComas, D. J. [Southwest Research Institute, P.O. Drawer 28510, San Antonio, TX 78228 (United States); Pogorelov, N. V. [Physics Department, University of Alabama in Huntsville, Huntsville, AL 35899 (United States)

    2013-05-10

    We examined solar wind plasma and interplanetary magnetic field (IMF) observations from Ulysses' first and third orbits to study hemispheric differences in the properties of the solar wind and IMF originating from the Sun's large polar coronal holes (PCHs) during the declining and minimum phase of solar cycles 22 and 23. We identified hemispheric asymmetries in several parameters, most notably {approx}15%-30% south-to-north differences in averages for the solar wind density, mass flux, dynamic pressure, and energy flux and the radial and total IMF magnitudes. These differences were driven by relatively larger, more variable solar wind density and radial IMF between {approx}36 Degree-Sign S-60 Degree-Sign S during the declining phase of solar cycles 22 and 23. These observations indicate either a hemispheric asymmetry in the PCH output during the declining and minimum phase of solar cycles 22 and 23 with the southern hemisphere being more active than its northern counterpart, or a solar cycle effect where the PCH output in both hemispheres is enhanced during periods of higher solar activity. We also report a strong linear correlation between these solar wind and IMF parameters, including the periods of enhanced PCH output, that highlight the connection between the solar wind mass and energy output and the Sun's magnetic field. That these enhancements were not matched by similar sized variations in solar wind speed points to the mass and energy responsible for these increases being added to the solar wind while its flow was subsonic.

  17. Constraints on observing brightness asymmetries in protoplanetary disks at solar system scale

    Science.gov (United States)

    Brunngräber, Robert; Wolf, Sebastian

    2018-04-01

    We have quantified the potential capabilities of detecting local brightness asymmetries in circumstellar disks with the Very Large Telescope Interferometer (VLTI) in the mid-infrared wavelength range. The study is motivated by the need to evaluate theoretical models of planet formation by direct observations of protoplanets at early evolutionary stages, when they are still embedded in their host disk. Up to now, only a few embedded candidate protoplanets have been detected with semi-major axes of 20-50 au. Due to the small angular separation from their central star, only long-baseline interferometry provides the angular resolving power to detect disk asymmetries associated to protoplanets at solar system scales in nearby star-forming regions. In particular, infrared observations are crucial to observe scattered stellar radiation and thermal re-emission in the vicinity of embedded companions directly. For this purpose we performed radiative transfer simulations to calculate the thermal re-emission and scattered stellar flux from a protoplanetary disk hosting an embedded companion. Based on that, visibilities and closure phases are calculated to simulate observations with the future beam combiner MATISSE, operating at the L, M and N bands at the VLTI. We find that the flux ratio of the embedded source to the central star can be as low as 0.5 to 0.6% for a detection at a feasible significance level due to the heated dust in the vicinity of the embedded source. Furthermore, we find that the likelihood for detection is highest for sources at intermediate distances r ≈ 2-5 au and disk masses not higher than ≈10-4 M⊙.

  18. CuS/RGO hybrid photocatalyst for full solar spectrum photoreduction from UV/Vis to near-infrared light.

    Science.gov (United States)

    Wu, Jie; Liu, Baibai; Ren, Zhenxing; Ni, Mengying; Li, Can; Gong, Yinyan; Qin, Wei; Huang, Yongli; Sun, Chang Q; Liu, Xinjuan

    2018-05-01

    To make full use of the solar energy, it remains a great challenge for semiconductor photocatalysts to harvest the full solar light spectrum from ultraviolet (UV) to visible even the near infrared (NIR) wavelength. Here we show firstly the CuS/RGO (reduced graphene oxide) hybrid photocatalyst synthesized via a microwave assisted method with full solar light (UV-Vis-NIR) active for efficient Cr(VI) reduction. The CuS/RGO displays high absorption and catalytic activity in the UV, visible and even the NIR light regions. As co-catalyst, RGO can separate and inhibit the recombination of charge carriers, consequently improving the catalytic activity. Only 1wt% RGO emersions can reduce 90% of Cr(VI) under the radiation of light over the full spectrum. Findings may provide a new strategy and substance to expand the utilization range of solar light from UV to visible even the NIR energy. Copyright © 2017. Published by Elsevier Inc.

  19. Development of gridded solar radiation data over Belgium based on Meteosat and in-situ observations

    Science.gov (United States)

    Journée, Michel; Vanderveken, Gilles; Bertrand, Cédric

    2013-04-01

    Knowledge on solar resources is highly important for all forms of solar energy applications. With the recent development in solar-based technologies national meteorological services are faced with increasing demands for high-quality and reliable site-time specific solar resource information. Traditionally, solar radiation is observed by means of networks of meteorological stations. Costs for installation and maintenance of such networks are very high and national networks comprise only few stations. Consequently the availability of ground-based solar radiation measurements has proven to be spatially and temporally inadequate for many applications. To overcome such a limitation, a major effort has been undertaken at the Royal Meteorological Institute of Belgium (RMI) to provide the solar energy industry, the electricity sector, governments, and renewable energy organizations and institutions with the most suitable and accurate information on the solar radiation resources at the Earth's surface over the Belgian territory. Only space-based observations can deliver a global coverage of the solar irradiation impinging on horizontal surface at the ground level. Because only geostationary data allow to capture the diurnal cycle of the solar irradiance at the Earth's surface, a method that combines information from Meteosat Second Generation satellites and ground-measurement has been implemented at RMI to generate high resolution solar products over Belgium on an operational basis. Besides these new products, the annual and seasonal variability of solar energy resource was evaluated, solar radiation climate zones were defined and the recent trend in solar radiation was characterized.

  20. RESOLVED MILLIMETER-WAVELENGTH OBSERVATIONS OF DEBRIS DISKS AROUND SOLAR-TYPE STARS

    Energy Technology Data Exchange (ETDEWEB)

    Steele, Amy; Hughes, A. Meredith [Department of Astronomy, Van Vleck Observatory, Wesleyan University, 96 Foss Hill Drive, Middletown, CT, 06459 (United States); Carpenter, John [Division of Physics, Mathematics, and Astronomy, MC249-17, California Institute of Technology, Pasadena, CA 91125 (United States); Ricarte, Angelo [J. W. Gibbs Laboratory, Department of Astronomy, Yale University, 260 Whitney Avenue, New Haven, CT 06511 (United States); Andrews, Sean M.; Wilner, David J. [Harvard-Smithsonian Center for Astrophysics, MS-42, 60 Garden Street, Cambridge, MA 02138 (United States); Chiang, Eugene, E-mail: asteele@wesleyan.edu [Department of Astronomy, 501 Campbell Hall, University of California, Berkeley, CA 94720-3411 (United States)

    2016-01-01

    The presence of debris disks around young main-sequence stars hints at the existence and structure of planetary systems. Millimeter-wavelength observations probe large grains that trace the location of planetesimal belts. The Formation and Evolution of Planetary Systems Spitzer Legacy survey of nearby young solar analogues yielded a sample of five debris disk-hosting stars with millimeter flux suitable for interferometric follow-up. We present observations with the Submillimeter Array (SMA) and the Combined Array for Research in Millimeter-wave Astronomy at ∼2″ resolution that spatially resolve the debris disks around these nearby (d ∼ 50 pc) stars. Two of the five disks (HD 377, HD 8907) are spatially resolved for the first time and one (HD 104860) is resolved at millimeter wavelengths for the first time. We combine our new observations with archival SMA and Atacama Large Millimeter/Submillimeter Array data to enable a uniform analysis of the full five-object sample. We simultaneously model the broadband photometric data and resolved millimeter visibilities to constrain the dust temperatures and disk morphologies, and perform a Markov Chain Monte Carlo analysis to fit for basic structural parameters. We find that the radii and widths of the cold outer belts exhibit properties consistent with scaled-up versions of the Solar System's Kuiper Belt. All the disks exhibit characteristic grain sizes comparable to the blowout size, and all the resolved observations of emission from large dust grains are consistent with an axisymmetric dust distribution to within the uncertainties. These results are consistent with comparable studies carried out at infrared wavelengths.

  1. Submillimeter and far infrared line observations of M17 SW: A clumpy molecular cloud penetrated by UV radiation

    Science.gov (United States)

    Stutzki, J.; Stacey, G. J.; Genzel, R.; Harris, A. I.; Jaffe, d. T.; Lugten, J. B.

    1987-01-01

    Millimeter, submillimeter, and far infrared spectroscopic observations of the M17 SW star formation region are discussed. The results require the molecular cloud near the interface to be clumpy or filamentary. As a consequence, far ultraviolet radiation from the central OB stellar cluster can penetrate into the dense molecular cloud to a depth of several pc, thus creating bright and extended (CII) emission from the photodissociated surfaces of dense atomic and molecular clumps or sheets. The extended (CII) emission throughout the molecular cloud SW of the M17 complex has a level 20 times higher than expected from a single molecular cloud interface exposed to an ultraviolet radiation field typical of the solar neighborhood. This suggests that the molecular cloud as a whole is penetrated by ultraviolet radiation and has a clumpy or filamentary structure. The number of B stars expected to be embedded in the M17 molecular cloud probably can provide the UV radiation necessary for the extended (CII) emission. Alternatively, the UV radiation could be external, if the interstellar radiation in the vicinity of M17 is higher than in the solar neighborhood.

  2. High-efficiency near-infrared enabled planar perovskite solar cells by embedding upconversion nanocrystals.

    Science.gov (United States)

    Meng, Fan-Li; Wu, Jiao-Jiao; Zhao, Er-Fei; Zheng, Yan-Zhen; Huang, Mei-Lan; Dai, Li-Ming; Tao, Xia; Chen, Jian-Feng

    2017-11-30

    Integration of the upconversion effect in perovskite solar cells (PSCs) is a facile approach towards extending the spectral absorption from the visible to the near infrared (NIR) range and reducing the non-absorption loss of solar photons. However, the big challenge for practical application of UCNCs in planar PSCs is the poor compatibility between UCNCs and the perovskite precursor. Herein, we have subtly overcome the tough compatibility issue using a ligand-exchange strategy. For the first time, β-NaYF 4 :Yb,Er UCNCs have been embedded in situ into a CH 3 NH 3 PbI 3 layer to fabricate NIR-enabled planar PSCs. The CH 3 NH 3 I-capped UCNCs generated from the ligand-exchange were mixed with the perovskite precursor and served as nucleation sites for the UCNC-mediated heteroepitaxial growth of perovskite; moreover, the in situ embedding of UCNCs into the perovskite layer was realized during a spin-coating process. The resulting UCNC-embedded perovskite layer attained a uniform pinhole-free morphology with enlarged crystal grains and enabled NIR absorption. It also contributed to the energy transfer from the UCNCs to the perovskite and electron transport to the collecting electrode surface. The device fabricated using the UCNC-embedded perovskite film achieved an average power-conversion efficiency of 18.60% (19.70% for the best) under AM 1.5G and 0.37% under 980 nm laser, corresponding to 54% and 740-fold increase as compared to that of its counterpart without UCNCs.

  3. Fabrication of thin-film thermoelectric generators with ball lenses for conversion of near-infrared solar light

    OpenAIRE

    Ito, Yoshitaka; Mizoshiri, Mizue; Mikami, Masashi; Kondo, Tasuku; Sakurai, Junpei; Hata, Seiichi

    2017-01-01

    We designed and fabricated thin-film thermoelectric generators (TEGs) with ball lenses, which separated visible light and near-infrared (NIR) solar light using a chromatic aberration. The transmitted visible light was used as daylight and the NIR light was used for thermoelectric generation. Solar light was estimated to be separated into the visible light and NIR light by a ray tracing method. 92.7% of the visible light was used as daylight and 9.9% of the NIR light was used for thermoelectri...

  4. Cause of solar wind speed variations observed at 1 a.u

    International Nuclear Information System (INIS)

    Hakamada, K.; Akasofu, S.

    1981-01-01

    An attempt is made to interpret solar wind variations observed at the earth's distance, namely the solar cycle variations, the semi-annual variations, and the 27-day variations, as well as the polarity changes of the interplanetary magnetic field, mainly in terms of two effects, a positive latitudinal gradient of the solar wind speed and a wobbling solar dipole, combined with the annual (heliospheric) latitudinal excursion of the earth. It is shown that a significant part of the solar wind variations observed at the earth's distance and the changes of polarity pattern of the interplanetary magnetic field can be reasonably well reproduced by the two effects

  5. Solar wind modulation of the Martian ionosphere observed by Mars Global Surveyor

    Directory of Open Access Journals (Sweden)

    J.-S. Wang

    2004-06-01

    Full Text Available Electron density profiles in the Martian ionosphere observed by the radio occultation experiment on board Mars Global Surveyor have been analyzed to determine if the densities are influenced by the solar wind. Evidence is presented that the altitude of the maximum ionospheric electron density shows a positive correlation to the energetic proton flux in the solar wind. The solar wind modulation of the Martian ionosphere can be attributed to heating of the neutral atmosphere by the solar wind energetic proton precipitation. The modulation is observed to be most prominent at high solar zenith angles. It is argued that this is consistent with the proposed modulation mechanism.

  6. Solar-wind predictions for the Parker Solar Probe orbit. Near-Sun extrapolations derived from an empirical solar-wind model based on Helios and OMNI observations

    Science.gov (United States)

    Venzmer, M. S.; Bothmer, V.

    2018-03-01

    Context. The Parker Solar Probe (PSP; formerly Solar Probe Plus) mission will be humanitys first in situ exploration of the solar corona with closest perihelia at 9.86 solar radii (R⊙) distance to the Sun. It will help answer hitherto unresolved questions on the heating of the solar corona and the source and acceleration of the solar wind and solar energetic particles. The scope of this study is to model the solar-wind environment for PSPs unprecedented distances in its prime mission phase during the years 2018 to 2025. The study is performed within the Coronagraphic German And US SolarProbePlus Survey (CGAUSS) which is the German contribution to the PSP mission as part of the Wide-field Imager for Solar PRobe. Aim. We present an empirical solar-wind model for the inner heliosphere which is derived from OMNI and Helios data. The German-US space probes Helios 1 and Helios 2 flew in the 1970s and observed solar wind in the ecliptic within heliocentric distances of 0.29 au to 0.98 au. The OMNI database consists of multi-spacecraft intercalibrated in situ data obtained near 1 au over more than five solar cycles. The international sunspot number (SSN) and its predictions are used to derive dependencies of the major solar-wind parameters on solar activity and to forecast their properties for the PSP mission. Methods: The frequency distributions for the solar-wind key parameters, magnetic field strength, proton velocity, density, and temperature, are represented by lognormal functions. In addition, we consider the velocity distributions bi-componental shape, consisting of a slower and a faster part. Functional relations to solar activity are compiled with use of the OMNI data by correlating and fitting the frequency distributions with the SSN. Further, based on the combined data set from both Helios probes, the parameters frequency distributions are fitted with respect to solar distance to obtain power law dependencies. Thus an empirical solar-wind model for the inner

  7. Characterization of NPP Visible/Infrared Imager Radiometer Suite (VIIRS) Reflective Solar Bands Dual Gain Anomaly

    Science.gov (United States)

    Lee, Shihyan; McIntire, Jeff; Oudari, Hassan

    2012-01-01

    The Visible/Infrared Imager Radiometer Suite (VIIRS) contains six dual gain bands in the reflective solar spectrum. The dual gain bands are designed to switch gain mode at pre-defined thresholds to achieve high resolution at low radiances while maintaining the required dynamic range for science. During pre-launch testing, an anomaly in the electronic response before transitioning from high to low gain was discovered and characterized. On-orbit, the anomaly was confirmed using MODIS data collected during Simultaneous Nadir Overpasses (SNOs). The analysis of the Earth scene data shows that dual gain anomaly can be determined at the orbital basis. To characterize the dual gain anomaly, the anomaly region and electronic offsets were tracked per week during the first 8 month of VIIRS operation. The temporal analysis shows the anomaly region can drift 20 DN and is impacted by detectors DC Restore. The estimated anomaly flagging regions cover 2.5 % of the high gain dynamic range and are consistent with prelaunch and on-orbit LUT. The prelaunch results had a smaller anomaly range (30-50 DN) and are likely the results of more stable electronics from the shorter data collection time. Finally, this study suggests future calibration efforts to focus on the anomaly's impact on science products and possible correction method to reduce uncertainties.

  8. Near-Infrared Keck Interferometer and IOTA Closure Phase Observations of Wolf-Rayet stars

    Science.gov (United States)

    Rajagopal, J.; Wallace, D.; Barry, R.; Richardson, L. J.; Traub, W.; Danchi, W. C.

    We present first results from observations of a small sample of IR-bright Wolf-Rayet stars with the Keck Interferometer in the near-infrared, and with the IONIC beam three-telescope beam combiner at the Infrared and Optical Telescope Array (IOTA) observatory. The former results were obtained as part of shared-risk observations in commissioning the Keck Interferometer and form a subset of a high-resolution study of dust around Wolf-Rayet stars using multiple interferometers in progress in our group. The latter results are the first closure phase observations of these stars in the near-infrared in a separated telescope interferometer. Earlier aperture-masking observations with the Keck-I telescope provide strong evidence that dust-formation in late-type WC stars are a result of wind-wind collision in short-period binaries.Our program with the Keck interferometer seeks to further examine this paradigm at much higher resolution. We have spatially resolved the binary in the prototypical dusty WC type star WR 140. WR 137, another episodic dust-producing star, has been partially resolved for the first time, providing the first direct clue to its possible binary nature.We also include WN stars in our sample to investigate circumstellar dust in this other main sub-type of WRs. We have been unable to resolve any of these, indicating a lack of extended dust.Complementary observations using the MIDI instrument on the VLTI in the mid-infrared are presented in another contribution to this workshop.

  9. THE EXTRAORDINARY FAR-INFRARED VARIATION OF A PROTOSTAR: HERSCHEL/PACS OBSERVATIONS OF LRLL54361

    Energy Technology Data Exchange (ETDEWEB)

    Balog, Zoltan; Detre, Örs H.; Bouwmann, Jeroen; Nielbock, Markus; Klaas, Ulrich; Krause, Oliver; Henning, Thomas [Max Planck Institute for Astronomy Königstuhl 17, Heidelberg D-69117 (Germany); Muzerolle, James [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Flaherty, Kevin [Astronomy Department, Wesleyan University, Middletown, CT 06459 (United States); Furlan, Elise [Natinal Optical Astronomy Observatory, 950 N. Cherry Avenue, Tucson, AZ 85719 (United States); Gutermuth, Rob [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); Juhasz, Attila [Leiden Observatory, Leiden University, Niels Bohrweg 2, NL-2333-CA Leiden (Netherlands); Bally, John [CASA, University of Colorado, CB 389, Boulder, CO 80309 (United States); Marton, Gabor, E-mail: balog@mpia.de [Konkoly Observatory, Research Center for Astronomy and Earth Sciences, Hungarian Academy of Sciences, Konkoly Thege 15-17, 1121 Budapest (Hungary)

    2014-07-10

    We report Herschel/Photodetector Array Camera and Spectrometer (PACS) photometric observations at 70 μm and 160 μm of LRLL54361—a suspected binary protostar that exhibits periodic (P = 25.34 days) flux variations at shorter wavelengths (3.6 μm and 4.5 μm) thought to be due to pulsed accretion caused by binary motion. The PACS observations show unprecedented flux variation at these far-infrared wavelengths that are well correlated with the variations at shorter wavelengths. At 70 μm the object increases its flux by a factor of six while at 160 μm the change is about a factor of two, consistent with the wavelength dependence seen in the far-infrared spectra. The source is marginally resolved at 70 μm with varying FWHM. Deconvolved images of the sources show elongations exactly matching the outflow cavities traced by the scattered light observations. The spatial variations are anti-correlated with the flux variation, indicating that a light echo is responsible for the changes in FWHM. The observed far-infrared flux variability indicates that the disk and envelope of this source is periodically heated by the accretion pulses of the central source, and suggests that such long wavelength variability in general may provide a reasonable proxy for accretion variations in protostars.

  10. Recent changes in solar irradiance and infrared irradiance related with air temperature and cloudiness at the King Sejong Station, Antarctica

    Science.gov (United States)

    Jung, Y.; Kim, J.; Cho, H.; Lee, B.

    2006-12-01

    The polar region play a critical role in the surface energy balance and the climate system of the Earth. The important question in the region is that what is the role of the Antarctic atmospheric heat sink of global climate. Thus, this study shows the trends of global solar irradiance, infrared irradiance, air temperature and cloudiness measured at the King Sejong station, Antarctica, during the period of 1996-2004 and determines their relationship and variability of the surface energy balance. Annual average of solar radiation and cloudiness is 81.8 Wm-2 and 6.8 oktas and their trends show the decrease of -0.24 Wm-2yr-1(-0.30 %yr-1) and 0.02 oktas yr-1(0.30 %yr-1). The change of solar irradiance is directly related to change of cloudiness and decrease of solar irradiance presents radiative cooling at the surface. Monthly mean infrared irradiance, air temperature and specific humidity shows the decrease of -2.11 Wm^{- 2}yr-1(-0.75 %yr-1), -0.07 'Cyr-1(-5.15 %yr-1) and -0.044 gkg-1yr-1(-1.42 %yr-1), respectively. Annual average of the infrared irradiance is 279.9 Wm-2 and correlated with the air temperature, specific humidity and cloudiness. A multiple regression model for estimation of the infrared irradiance using the components has been developed. Effects of the components on the infrared irradiance changes show 52 %, 19 % and 10 % for air temperature, specific humidity and cloudiness, respectively. Among the components, air temperature has a great influence on infrared irradiance. Despite the increase of cloudiness, the decrease in the infrared irradiance is due to the decrease of air temperature and specific humidity which have a cooling effect. Therefore, the net radiation of the surface energy balance shows radiative cooling of negative 11-24 Wm^{- 2} during winter and radiative warming of positive 32-83 Wm-2 during the summer. Thus, the amount of shortage and surplus at the surface is mostly balanced by turbulent flux of sensible and latent heat.

  11. Status of the solar and infrared radiation submodels in the LLNL 1-D and 2-D chemical-transport models

    International Nuclear Information System (INIS)

    Grant, K.E.; Taylor, K.E.; Ellis, J.S.; Wuebbles, D.J.

    1987-07-01

    The authors have implemented a series of state of the art radiation transport submodels in previously developed one dimensional and two dimensional chemical transport models of the troposphere and stratosphere. These submodels provide the capability of calculating accurate solar and infrared heating rates. They are a firm basis for further radiation submodel development as well as for studying interactions between radiation and model dynamics under varying conditions of clear sky, clouds, and aerosols. 37 refs., 3 figs

  12. Giant quiescent solar filament observed with high-resolution spectroscopy

    Science.gov (United States)

    Kuckein, C.; Verma, M.; Denker, C.

    2016-05-01

    Aims: An extremely large filament was studied in various layers of the solar atmosphere. The inferred physical parameters and the morphological aspects are compared with smaller quiescent filaments. Methods: A giant quiet-Sun filament was observed with the high-resolution Echelle spectrograph at the Vacuum Tower Telescope at Observatorio del Teide, Tenerife, Spain, on 2011 November 15. A mosaic of spectra (ten maps of 100″ × 182″) was recorded simultaneously in the chromospheric absorption lines Hα and Na I D2. Physical parameters of the filament plasma were derived using cloud model (CM) inversions and line core fits. The spectra were complemented with full-disk filtergrams (He I λ10830 Å, Hα, and Ca II K) of the Chromospheric Telescope (ChroTel) and full-disk magnetograms of the Helioseismic and Magnetic Imager (HMI). Results: The filament had extremely large linear dimensions (~817 arcsec), which corresponds to about 658 Mm along a great circle on the solar surface. A total amount of 175119 Hα contrast profiles were inverted using the CM approach. The inferred mean line-of-sight (LOS) velocity, Doppler width, and source function were similar to previous works of smaller quiescent filaments. However, the derived optical thickness was higher. LOS velocity trends inferred from the Hα line core fits were in accord but weaker than those obtained with CM inversions. Signatures of counter-streaming flows were detected in the filament. The largest brightening conglomerates in the line core of Na I D2 coincided well with small-scale magnetic fields as seen by HMI. Mixed magnetic polarities were detected close to the ends of barbs. The computation of photospheric horizontal flows based on HMI magnetograms revealed flow kernels with a size of 5-8 Mm and velocities of 0.30-0.45 km s-1 at the ends of the filament. Conclusions: The physical properties of extremely large filaments are similar to their smaller counterparts, except for the optical thickness, which in

  13. Solar wind temperature observations in the outer heliosphere

    Science.gov (United States)

    Gazis, P. R.; Barnes, A.; Mihalov, J. D.; Lazarus, A. J.

    1992-01-01

    The Pioneer 10, Pioneer 11, and Voyager 2 spacecraft are now at heliocentric distances of 50, 32 and 33 AU, and heliographic latitudes of 3.5 deg N, 17 deg N, and 0 deg N, respectively. Pioneer 11 and Voyager 2 are at similar celestial longitudes, while Pioneer l0 is on the opposite side of the sun. The baselines defined by these spacecraft make it possible to resolve radial, longitudinal, and latitudinal variations of solar wind parameters. The solar wind temperature decreases with increasing heliocentric distance out to a distance of 10-15 AU. At larger heliocentric distances, this gradient disappears. These high solar wind temperatures in the outer heliosphere have persisted for at least 10 years, which suggests that they are not a solar cycle effect. The solar wind temperature varied with heliographic latitude during the most recent solar minimum. The solar wind temperature at Pioneer 11 and Voyager 2 was higher than that seen at Pioneer 10 for an extended period of time, which suggests the existence of a large-scale variation of temperature with celestial longitude, but the contribution of transient phenomena is yet to be clarified.

  14. Observation of runaway electrons by infrared camera in J-TEXT

    Energy Technology Data Exchange (ETDEWEB)

    Tong, R. H.; Chen, Z. Y., E-mail: zychen@hust.edu.cn; Zhang, M.; Huang, D. W.; Yan, W.; Zhuang, G. [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2016-11-15

    When the energy of confined runaway electrons approaches several tens of MeV, the runaway electrons can emit synchrotron radiation in the range of infrared wavelength. An infrared camera working in the wavelength of 3-5 μm has been developed to study the runaway electrons in the Joint Texas Experimental Tokamak (J-TEXT). The camera is located in the equatorial plane looking tangentially into the direction of electron approach. The runaway electron beam inside the plasma has been observed at the flattop phase. With a fast acquisition of the camera, the behavior of runaway electron beam has been observed directly during the runaway current plateau following the massive gas injection triggered disruptions.

  15. Spectropolarimetric Observations of Solar Noise Storms at Low Frequencies

    Science.gov (United States)

    Mugundhan, V.; Ramesh, R.; Kathiravan, C.; Gireesh, G. V. S.; Hegde, Aathira

    2018-03-01

    A new high-resolution radio spectropolarimeter instrument operating in the frequency range of 15 - 85 MHz has recently been commissioned at the Radio Astronomy Field Station of the Indian Institute of Astrophysics at Gauribidanur, 100 km north of Bangalore, India. We describe the design and construction of this instrument. We present observations of a solar radio noise storm associated with Active Region (AR) 12567 in the frequency range of {≈} 15 - 85 MHz during 18 and 19 July 2016, observed using this instrument in the meridian-transit mode. This is the first report that we are aware of in which both the burst and continuum properties are derived simultaneously. Spectral indices and degree of polarization of both the continuum radiation and bursts are estimated. It is found that i) Type I storm bursts have a spectral index of {≈} {+}3.5, ii) the spectral index of the background continuum is ≈+2.9, iii) the transition frequency between Type I and Type III storms occurs at ≈55 MHz, iv) Type III bursts have an average spectral index of ≈-2.7, v) the spectral index of the Type III continuum is ≈-1.6, and vi) the degree of circular polarization of all Type I (Type III) bursts is ≈90% (30%). The results obtained here indicate that the continuum emission is due to bursts occurring in rapid succession. We find that the derived parameters for Type I bursts are consistent with suprathermal electron acceleration theory and those of Type III favor fundamental plasma emission.

  16. Graphical User Interface for an Observing Control System for the UK Infrared Telescope

    Science.gov (United States)

    Tan, M.; Bridger, A.; Wright, G. S.; Adamson, A. J.; Currie, M. J.; Economou, F.

    A Graphical user interface for the observing control system of UK Infrared Telescope has been developed as a part of the ORAC (Observatory Reduction and Acquisition Control) Project. We analyzed and designed the system using the Unified Modelling Language (UML) with the CASE tool Rational Rose 98. The system has been implemented in a modular way with Java packages using Swing and RMI. This system is component-based with pluggability. Object orientation concepts and UML notations have been applied throughout the development.

  17. High spatial resolution observations of the T Tau system - II. Interferometry in the mid-infrared

    International Nuclear Information System (INIS)

    Ratzka, Thorsten

    2008-01-01

    Each time the resolution was improved, observations of the young low-mass star T Tau led to new insights. Initially classified as the prototype of low-mass pre-main-sequence stars, measurements with high resolution techniques in the near-infrared revealed the existence of a deeply embedded companion only 0.7 arcsec to the south. Later on, this companion itself has been resolved into two sources with a separation of only about 50 mas. We investigated both the optically bright northern component and the embedded southern binary with the MID-infrared Interferometric instrument (MIDI). The resulting visibilities of the northern component decrease with wavelength, independent of the baseline's position angle. This is a clear sign of the large face-on circumstellar disc. With a simultaneous fit of a radiative transfer model to both the interferometric results and the spectral energy distribution, the properties of this disc can be determined without the high degeneracy of fits to the spectral energy distribution alone. Since the visibilities of the southern binary are clearly dominated by the typical sinusoidal binary signal, we could for the first time in the mid-infrared derive separate spectra for both components together with a very precise relative position. This position is in excellent agreement with the orbit found from a fit to the near-infrared adaptive optics measurements. The orbit with its small periastron distance indicates tidally truncated discs, which are consistent with the interferometric measurements. The peculiar properties of the infrared companion can be explained by the model of an intermediate mass star extincted by an almost edge-on disc.

  18. Energetic molecular outflow near AFGL 961: millimeter-wave and infrared observations

    International Nuclear Information System (INIS)

    Lada, C.J.; Gautier, T.N. III

    1982-01-01

    We report detailed millimeter-wave and near-infrared spectroscopy of the dynamically active region around the infrared source AFGL 961, near the Rosette nebula. Millimeter-wave 12 CO observations are used to study the high-velocity molecular flow around AFGL 961. These observations show that the high-velocity flow has a maximum extent of at least 6' or 2.9 pc at the distance of AFGL 961. The flow is found to be anisotropic, with redshifted high-velocity emission considerably more extended than blueshifted high-velocity emission. However, the flow does not appear to be as highly collimated as some other sources of high-velocity bipolar outflow. We also find the emission profiles to be asymmetric in velocity such that the integrated intensity of the redshifted high-velocity emission is on average 2.5 times greater than that of the blueshifted emission. The mass of the gas involved in the flow is determined to be approximately 19 M/sub sun/, and the kinetic energy of this gas is estimated to be about 8 x 10 46 ergs. These observations are interpreted as evidence that an energetic bipolar outflow of molecular gas is occurring near AFGL 961. The momentum of the outflowing molecular gas is large, and it is shown that this places strong constraints on possible physical mechanisms which may be driving the outflow. The near-infrared spectrum of AFGL 961 from 1.4-2.4 μm was obtained in order to study the conditions immediately around the infrared source which may be driving the molecular outflow

  19. Multi-Wavelength Observations of Asteroid 2100 Ra-Shalom: Visible, Infrared, and Thermal Spectroscopy Results

    Science.gov (United States)

    Clark, Beth Ellen; Shepard, M.; Bus, S. J.; Vilas, F.; Rivkin, A. S.; Lim, L.; Lederer, S.; Jarvis, K.; Shah, S.; McConnochie, T.

    2004-01-01

    The August 2003 apparition of asteroid 2100 Ra-Shalom brought together a collaboration of observers with the goal of obtaining rotationally resolved multiwavelength spectra at each of 5 facilities: infrared spectra at the NASA Infrared Telescope Facility (Clark and Shepard), radar images at Arecibo (Shepard and Clark), thermal infrared spectra at Palomar (Lim, McConnochie and Bell), visible spectra at McDonald Observatory (Vilas, Lederer and Jarvis), and visible lightcurves at Ondrojev Observatory (Pravec). The radar data was to be used to develop a high spatial resolution physical model to be used in conjunction with spectral data to investigate compositional and textural properties on the near surface of Ra Shalom as a function of rotation phase. This was the first coordinated multi-wavelength investigation of any Aten asteroid. There are many reasons to study near-Earth asteroid (NEA) 2100 Ra-Shalom: 1) It has a controversial classification (is it a C- or K-type object)? 2) There would be interesting dynamical ramifications if Ra-Shalom is a K-type because most K-types come from the Eos family and there are no known dynamical pathways from Eos to the Aten population. 3) The best available spectra obtained previously may indicate a heterogeneous surface (most asteroids appear to be fairly homogeneous). 4) Ra-Shalom thermal observations obtained previously indicated a lack of regolith, minimizing the worry of space weathering effects in the spectra. 5) Radar observations obtained previously hinted at interesting surface structures. 6) Ra-Shalom is one of the largest Aten objects. And 7) Ra-Shalom is on a short list of proposed NEAs for spacecraft encounters and possible sample returns. Preliminary results from the visible, infrared, and thermal spectroscopy measurements will be presented here.

  20. OBSERVATIONS OF LINEAR POLARIZATION IN A SOLAR CORONAL LOOP PROMINENCE SYSTEM OBSERVED NEAR 6173 Å

    Energy Technology Data Exchange (ETDEWEB)

    Saint-Hilaire, Pascal; Martínez Oliveros, Juan-Carlos; Hudson, Hugh S.; Krucker, Säm; Bain, Hazel [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Schou, Jesper [Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, D-37077 Göttingen (Germany); Couvidat, Sébastien, E-mail: shilaire@ssl.berkeley.edu [W. W. Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305 (United States)

    2014-05-10

    White-light observations by the Solar Dynamics Observatory's Helioseismic and Magnetic Imager of a loop-prominence system occurring in the aftermath of an X-class flare on 2013 May 13 near the eastern solar limb show a linearly polarized component, reaching up to ∼20% at an altitude of ∼33 Mm, about the maximum amount expected if the emission were due solely to Thomson scattering of photospheric light by the coronal material. The mass associated with the polarized component was 8.2 × 10{sup 14} g. At 15 Mm altitude, the brightest part of the loop was 3(±0.5)% linearly polarized, only about 20% of that expected from pure Thomson scattering, indicating the presence of an additional unpolarized component at wavelengths near Fe I (617.33 nm). We estimate the free electron density of the white-light loop system to possibly be as high as 1.8 × 10{sup 12} cm{sup –3}.

  1. August 1972 solar-terrestrial events: interplanetary magnetic field observations

    Energy Technology Data Exchange (ETDEWEB)

    Smith, E J [Jet Propulsion Lab., Pasadena, Calif. (USA)

    1976-10-01

    A review is presented of the interplanetary magnetic field observations acquired in early August 1972 when four solar flares erupted in McMath Plage region 1976. Measurements of the interplanetary field were obtained by Earth satellites, HEOS-2 and Explorer 41, and by Pioneers 9 and 10 which, by good fortune, were radially aligned and only 45/sup 0/ east of the Earth-Sun direction. In response to the four flares, four interplanetary shocks were seen at Earth and at Pioneer 9, which was then at a heliocentric distance of 0.78 AU. However, at Pioneer 10, which was 2.2 AU from the Sun, only two forward shocks and one reverse shock were seen. The available magnetic field data acquired in the vicinity of the shocks are presented. Efforts to identify corresponding shocks at the several locations and to deduce their velocities of propagation between 0.8 and 2.2 AU are reviewed. The early studies were based on average velocities between the Sun and Pioneer 9, the Sun and Earth and the Sun and Pioneer 10. A large deceleration of the shocks between the Sun and 0.8 AU as well as between 0.8 and 2.2 AU was inferred. More recently the local velocities of the shocks at Pioneers 9 and 10 have become available. A comparision of these velocities shows little, if any, deceleration between 0.8 and 2.2 AU and implies that most or all of the deceleration actually occurred nearer the Sun. Evidence is also presented that shows a significant departure of the flare-generated shock fronts from spherical symmetry.

  2. Constraints on Circumstellar Dust Grain Sizes from High Spatial Resolution Observations in the Thermal Infrared

    Science.gov (United States)

    Bloemhof, E. E.; Danen, R. M.; Gwinn, C. R.

    1996-01-01

    We describe how high spatial resolution imaging of circumstellar dust at a wavelength of about 10 micron, combined with knowledge of the source spectral energy distribution, can yield useful information about the sizes of the individual dust grains responsible for the infrared emission. Much can be learned even when only upper limits to source size are available. In parallel with high-resolution single-telescope imaging that may resolve the more extended mid-infrared sources, we plan to apply these less direct techniques to interpretation of future observations from two-element optical interferometers, where quite general arguments may be made despite only crude imaging capability. Results to date indicate a tendency for circumstellar grain sizes to be rather large compared to the Mathis-Rumpl-Nordsieck size distribution traditionally thought to characterize dust in the general interstellar medium. This may mean that processing of grains after their initial formation and ejection from circumstellar atmospheres adjusts their size distribution to the ISM curve; further mid-infrared observations of grains in various environments would help to confirm this conjecture.

  3. Alma observations of nearby luminous infrared galaxies with various agn energetic contributions using dense gas tracers

    Energy Technology Data Exchange (ETDEWEB)

    Imanishi, Masatoshi [Subaru Telescope, 650 North A' ohoku Place, Hilo, HI 96720 (United States); Nakanishi, Kouichiro, E-mail: masa.imanishi@nao.ac.jp [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)

    2014-07-01

    We present the results of our ALMA Cycle 0 observations, using HCN/HCO{sup +}/HNC J = 4-3 lines, of six nearby luminous infrared galaxies with various energetic contributions from active galactic nuclei (AGNs) estimated from previous infrared spectroscopy. These lines are very effective for probing the physical properties of high-density molecular gas around the hidden energy sources in the nuclear regions of these galaxies. We find that HCN to HCO{sup +} J = 4-3 flux ratios tend to be higher in AGN-important galaxies than in starburst-dominated regions, as was seen at the J = 1-0 transition, while there is no clear difference in the HCN-to-HNC J = 4-3 flux ratios among observed sources. A galaxy with a starburst-type infrared spectral shape and very large molecular line widths shows a high HCN-to-HCO{sup +} J = 4-3 flux ratio, which could be due to turbulence-induced heating. We propose that enhanced HCN J = 4-3 emission relative to HCO{sup +} J = 4-3 could be used to detect more energetic activity than normal starbursts, including deeply buried AGNs, in dusty galaxy populations.

  4. b-dipole transitions in trans-HOCO observed by far infrared laser magnetic resonance

    International Nuclear Information System (INIS)

    Sears, T.J.; Radford, H.E.; Moore, M.A.

    1993-01-01

    Far infrared laser magnetic resonance spectroscopy is used to measure components of 12 rotational transitions in the ground state of the HOCO radical. The transitions are all b-dipole in character in contrast to the a-dipole rotational spectrum previously reported [Radford, Wei, and Sears, J. Chem. Phys. 97, 3989 (1992)]. The new data determine the A rotational constant to high precision and allow the determination of several centrifugal distortion constants for the first time. The hyperfine coupling in the radical leads to observable splittings in several of the observed transitions and these are used to estimate two of the four expected nonzero hyperfine parameters in the radical

  5. IRIS Observations of Spicules and Structures Near the Solar Limb

    Science.gov (United States)

    Alissandrakis, C. E.; Vial, J.-C.; Koukras, A.; Buchlin, E.; Chane-Yook, M.

    2018-02-01

    We have analyzed Interface Region Imaging Spectrograph (IRIS) spectral and slit-jaw observations of a quiet region near the South Pole. In this article we present an overview of the observations, the corrections, and the absolute calibration of the intensity. We focus on the average profiles of strong (Mg ii h and k, C ii and Si iv), as well as of weak spectral lines in the near ultraviolet (NUV) and the far ultraviolet (FUV), including the Mg ii triplet, thus probing the solar atmosphere from the low chromosphere to the transition region. We give the radial variation of bulk spectral parameters as well as line ratios and turbulent velocities. We present measurements of the formation height in lines and in the NUV continuum from which we find a linear relationship between the position of the limb and the intensity scale height. We also find that low forming lines, such as the Mg ii triplet, show no temporal variations above the limb associated with spicules, suggesting that such lines are formed in a homogeneous atmospheric layer and, possibly, that spicules are formed above the height of 2''. We discuss the spatio-temporal structure of the atmosphere near the limb from images of intensity as a function of position and time. In these images, we identify p-mode oscillations in the cores of lines formed at low heights above the photosphere, slow-moving bright features in O i and fast-moving bright features in C ii. Finally, we compare the Mg ii k and h line profiles, together with intensity values of the Balmer lines from the literature, with computations from the PROM57Mg non-LTE model, developed at the Institut d' Astrophysique Spatiale, and estimated values of the physical parameters. We obtain electron temperatures in the range of {˜} 8000 K at small heights to {˜} 20 000 K at large heights, electron densities from 1.1× 10^{11} to 4× 10^{10} cm^{-3} and a turbulent velocity of {˜} 24 km s^{-1}.

  6. Observations of far-infrared molecular emission lines from the Orion molecular cloud

    International Nuclear Information System (INIS)

    Viscuso, P.J.

    1986-01-01

    The Orion Nebula has been the subject of intensive study for over one hundred years. Far-infrared (FIR) molecular line observations of CO in the shock region surrounding the infrared source IRc2 have suggested that the molecular hydrogen density in the shocked and post-shock gas is roughly 3 x 10 6 cm -3 . The temperature of this gas is on the order of 750-2000K. IRc2, like other nearby infrared sources within the Nebula, is thought to be a site of recent star formation. This object is apparently at the center of a massive bipolar molecular outflow of gas, which is producing a shock front where it meets the ambient molecular cloud surrounding IRc2. Study of such regions is important for the understanding of the chemical and physical processes that are involved in the formation of stars from molecular clouds. Recently, several far-infrared transitions among the low-lying levels of OH have been observed toward IRc2. OH is thought to be abundant, and it plays an important role in the chemical evolution of the shock and post-shock regions. The OH emission serves as a sensitive probe of the temperature and density for the shock-processed gas. A rigorous treatment of the radiative transfer of these measured transitions is performed using the escape probability formalism. From this analysis, the author determines the temperature of the OH-emitting region to be on the order of 40K. This suggests that the gas is part of the post-shock gas that has cooled sufficiently, most likely by way of radiative cooling by CO

  7. Infrared Harvesting Colloidal Quantum Dot Solar Cell Based on Multi-scale Disordered Electrodes

    KAUST Repository

    Tian, Yi

    2015-06-23

    Colloidal quantum dot photovoltaics (CQDPV) offer a big potential to be a renewable energy source due to low cost and tunable band-gap. Currently, the certified power conversion efficiency of CQDPV has reached 9.2%. Compared to the 31% theoretical efficiency limit of single junction solar cells, device performances have still have a large potential to be improved. For photovoltaic devices, a classical way to enhance absorption is to increase the thickness of the active layers. Although this approach can improve absorption, it reduces the charge carriers extraction efficiency. Photo-generated carriers, in fact, are prone to recombine within the defects inside CQD active layers. In an effort to solve this problem, we proposed to increase light absorption from a given thickness of colloidal quantum dot layers with the assistance of disorder. Our approach is to develop new types of electrodes with multi-scale disordered features, which localize energy into the active layer through plasmonic effects. We fabricated nanostructured gold substrates by electrochemical methods, which allow to control surface disorder as a function of deposition conditions. We demonstrated that the light absorption from 600 nm to 800 nm is impressively enhanced, when the disorder of the nanostructured surface increases. Compared to the planar case, the most disorder case increased 65% light absorption at the wavelength of λ = 700nm in the 100 nm PbS film. The average absorption enhancement across visible and infrared region in 100 nm PbS film is 49.94%. By developing a photovoltaic module, we measured a dramatic 34% improvement in the short-circuit current density of the device. The power conversion efficiency of the tested device in top-illumination configuration showed 25% enhancement.

  8. Asteroids in the Inner Solar System - Observable Properties

    Science.gov (United States)

    Tabachnik, S. A.; Evans, N. W.

    2000-12-01

    This paper presents synthetic observations of long-lived, co-orbiting asteroids of Mercury, Venus, the Earth and Mars. Our sample is constructed by taking the limiting semimajor axes, differential longitudes and inclinations for long-lived stability provided by simulations. The intervals are randomly populated with values to create initial conditions. These orbits are re-simulated to check that they are stable and then re-sampled every 2.5 years for 1 million years. The Mercurian sample contains only horseshoe orbits, the Martian sample only tadpoles. For both Venus and the Earth, the greatest concentration of objects on the sky occurs close to the classical Lagrange points at heliocentric ecliptic longitudes of 60o and 300o. The distributions are broad especially if horseshoes are present in the sample. The full-width half maximum (FWHM) in heliocentric longitude for Venus is 325o and for the Earth is 328o. The mean and most common velocity of these co-orbiting satellites coincides with the mean motion of the parent planet, but again the spread is wide with a FWHM for Venus of 27.8" hr-1 and for the Earth of 21.0" hr-1. For Mars, the greatest concentration on the sky occurs at heliocentric ecliptic latitudes of +/- 12o. The peak of the velocity distribution occurs at 65" hr-1, significantly less than the Martian mean motion, while its FWHM is 32.3" hr-1. The case of Mercury is the hardest of all, as the greatest concentrations occur at heliocentric longitudes of 16.0o and 348.5o and so are different from the classical values. The fluctuating eccentricity of Mercury means that these objects can have velocities exceeding 1000" hr-1, although the most common velocity is 459" hr-1, which is much less than the Mercurian mean motion. A variety of search strategies are discussed, including wide-field CCD imaging, space satellites such as The Global Astrometry Interferometer for Astrophysics (GAIA), ground-based surveys like The Sloan Digital Sky Survey (SDSS), as well as

  9. Asteroids in the inner Solar system - II. Observable properties

    Science.gov (United States)

    Evans, N. W.; Tabachnik, S. A.

    2000-11-01

    This paper presents synthetic observations of long-lived coorbiting asteroids of Mercury, Venus, the Earth and Mars. Our sample is constructed by taking the limiting semimajor axes, differential longitudes and inclinations for long-lived stability provided by simulations. The intervals are randomly populated with values to create initial conditions. These orbits are re-simulated to check that they are stable and then re-sampled every 2.5yr for 1Myr. The Mercurian sample only contains horseshoe orbits, whereas the Martian sample only contains tadpoles. For both Venus and the Earth, the greatest concentration of objects on the sky occurs close to the classical Lagrange points at heliocentric ecliptic longitudes of 60° and 300°. The distributions are broad especially if horseshoes are present in the sample. The FWHM in heliocentric longitude for Venus is 325° and for the Earth is 328°. The mean and most common velocity of these coorbiting satellites coincides with the mean motion of the parent planet, but again the spread is wide with an FWHM of 27.8 and 21.0arcsech-1 for Venus and the Earth, respectively. For Mars, the greatest concentration on the sky occurs at heliocentric ecliptic latitudes of +/-12°. The peak of the velocity distribution occurs at 65arcsech-1, significantly less than the Martian mean motion, while its FWHM is 32.3arcsech-1. The case of Mercury is the hardest of all, as the greatest concentrations occur at heliocentric longitudes of 16.0° and 348.5° and so are different from the classical values. The fluctuating eccentricity of Mercury means that these objects can have velocities exceeding 1000arcsech-1 although the most common velocity is 459arcsech-1, which is much less than the Mercurian mean motion. A variety of search strategies are discussed, including wide-field CCD imaging, space satellites such as the Global Astrometry Interferometer for Astrophysics (GAIA), ground-based surveys like the Sloan Digital Sky Survey (SDSS), as well as

  10. Do In Situ Observations Contain Signatures of Intermittent Fast Solar Wind Acceleration?

    Science.gov (United States)

    Matteini, L.; Horbury, T. S.; Stansby, D.

    2017-12-01

    Disentangling local plasma properties and Solar origin structures in in situ data is a crucial aspect for the understanding of solar wind acceleration and evolution. This is particularly challenging at 1 AU and beyond, where structures of various origin have had time to interact and merge, smoothing out their main characteristics. Observations of more pristine plasma closer to the Sun are therefore needed. In preparation of the forthcoming Solar Orbiter and Parker Solar Probe missions, Helios observations as close as to 0.3 AU - although old, not yet fully exploited - can be used to test our expectations and make new predictions. Recent observations (Matteini et al. 2014, 2015) have outlined the presence of intense (up to 1000km/s) and short-living velocity peaks that ubiquitously characterize the typical profile of the fast solar wind at 0.3 AU, suggesting that these features could be remnants of processes occurring in the Solar atmosphere and a signature of intermittent solar wind acceleration from coronal holes. We discuss results about statistics of these events, characterizing their physical properties and trying to link them with typical Solar temporal and spatial scales. Finally we also discuss how these velocity peaks will likely affect the future in situ exploration of the inner heliosphere by Solar Orbiter and the Parker Solar Probe.

  11. Observations of the transmittance in two solar ponds

    Energy Technology Data Exchange (ETDEWEB)

    Almanza, R.; Bryant, M.C.

    1983-11-01

    A NaCl salt gradient solar pond has been in continuous operation at the University of New Mexico since the fall of 1975; a smaller pond, using KNO/sub 3/ to produce the salinity gradient, was commissioned in the fall of 1981. The distribution of absorbed radiation in the ponds is of key importance in the determination of their efficiencies for collecting and storing solar energy. The absorption coefficient of light in an aqueous solution is very dependent upon wavelength; the spectral distribution of sunlight shifts toward the blue and the amount of solar energy absorbed per unit length of path declines with depth of penetration. The presence of suspended solids and bioforms further complicate the transmittance of sun light through the pond, specially since this contamination tends to vary strongly with depth. Because of its importance to the phytoplankton population , considerable work has been done by oceanographers on the absorption and scattering of light for different wavelengths. However, in a solar pond the big question is the amount of energy reaching the lower convective layer (storage). Several attempts have been made to measure the transmittance in solar ponds, mainly NaCl but the problem is to find a temperature-insensitive submersible pyranometer. Convenient formulas have been offered for the attenuation of solar radiation in pond water by considering it to be divided into spectral bands, or by fitting simple analytical functions, or specifying the extintion coefficient. (For the first method, it is necessary to know the absorption and scattering of light for different lambda.) In this paper some measurements of transmittance in the UNM ponds, are presented thereby exhibiting a simple procedure which may be of interest to others in this field.

  12. "Slow-scanning" in Ground-based Mid-infrared Observations

    Science.gov (United States)

    Ohsawa, Ryou; Sako, Shigeyuki; Miyata, Takashi; Kamizuka, Takafumi; Okada, Kazushi; Mori, Kiyoshi; Uchiyama, Masahito S.; Yamaguchi, Junpei; Fujiyoshi, Takuya; Morii, Mikio; Ikeda, Shiro

    2018-04-01

    Chopping observations with a tip-tilt secondary mirror have conventionally been used in ground-based mid-infrared observations. However, it is not practical for next generation large telescopes to have a large tip-tilt mirror that moves at a frequency larger than a few hertz. We propose an alternative observing method, a "slow-scanning" observation. Images are continuously captured as movie data, while the field of view is slowly moved. The signal from an astronomical object is extracted from the movie data by a low-rank and sparse matrix decomposition. The performance of the "slow-scanning" observation was tested in an experimental observation with Subaru/COMICS. The quality of a resultant image in the "slow-scanning" observation was as good as in a conventional chopping observation with COMICS, at least for a bright point-source object. The observational efficiency in the "slow-scanning" observation was better than that in the chopping observation. The results suggest that the "slow-scanning" observation can be a competitive method for the Subaru telescope and be of potential interest to other ground-based facilities to avoid chopping.

  13. 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

  14. Distribution and solar wind control of compressional solar wind-magnetic anomaly interactions observed at the Moon by ARTEMIS

    Science.gov (United States)

    Halekas, J. S.; Poppe, A. R.; Lue, C.; Farrell, W. M.; McFadden, J. P.

    2017-06-01

    A statistical investigation of 5 years of observations from the two-probe Acceleration, Reconnection, Turbulence, and Electrodynamics of Moon's Interaction with the Sun (ARTEMIS) mission reveals that strong compressional interactions occur infrequently at high altitudes near the ecliptic but can form in a wide range of solar wind conditions and can occur up to two lunar radii downstream from the lunar limb. The compressional events, some of which may represent small-scale collisionless shocks ("limb shocks"), occur in both steady and variable interplanetary magnetic field (IMF) conditions, with those forming in steady IMF well organized by the location of lunar remanent crustal magnetization. The events observed by ARTEMIS have similarities to ion foreshock phenomena, and those observed in variable IMF conditions may result from either local lunar interactions or distant terrestrial foreshock interactions. Observed velocity deflections associated with compressional events are always outward from the lunar wake, regardless of location and solar wind conditions. However, events for which the observed velocity deflection is parallel to the upstream motional electric field form in distinctly different solar wind conditions and locations than events with antiparallel deflections. Consideration of the momentum transfer between incoming and reflected solar wind populations helps explain the observed characteristics of the different groups of events.Plain Language SummaryWe survey the environment around the Moon to determine when and where strong amplifications in the charged particle density and magnetic field strength occur. These structures may be some of the smallest shock waves in the solar system, and learning about their formation informs us about the interaction of charged particles with small-scale magnetic fields throughout the solar system and beyond. We find that these compressions occur in an extended region downstream from the lunar dawn and dusk regions and

  15. SPITZER OBSERVATIONS OF LONG-TERM INFRARED VARIABILITY AMONG YOUNG STELLAR OBJECTS IN CHAMAELEON I

    Energy Technology Data Exchange (ETDEWEB)

    Flaherty, Kevin M.; Herbst, William [Van Vleck Observatory, Astronomy Department, Wesleyan University, 96 Foss Hill Drive, Middletown, CT 06459 (United States); DeMarchi, Lindsay [Department of Physics and Astronomy, Colgate University, 13 Oak Drive, Hamilton, NY 13346 (United States); Muzerolle, James [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Balog, Zoltan [Max-Planck-Institut fur Astronomie, Konigstuhl 17, D-69117 Heidelberg (Germany); Megeath, S. Thomas [Ritter Astrophysical Research Center, Department of Physics and Astronomy, University of Toledo, Toledo, OH 43606 (United States); Furlan, Elise [Infrared Processing and Analysis Center, California Institute of Technology, 770 S. Wilson Avenue, Pasadena, CA 91125 (United States); Gutermuth, Robert [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States)

    2016-12-10

    Infrared variability is common among young stellar objects, with surveys finding daily to weekly fluctuations of a few tenths of a magnitude. Space-based observations can produce highly sampled infrared light curves, but are often limited to total baselines of about 1 month due to the orientation of the spacecraft. Here we present observations of the Chameleon I cluster, whose low declination makes it observable by the Spitzer Space Telescope over a 200-day period. We observe 30 young stellar objects with a daily cadence to better sample variability on timescales of months. We find that such variability is common, occurring in ∼80% of the detected cluster members. The change in [3.6]–[4.5] color over 200 days for many of the sources falls between that expected for extinction and fluctuations in disk emission. With our high cadence and long baseline we can derive power spectral density curves covering two orders of magnitude in frequency and find significant power at low frequencies, up to the boundaries of our 200-day survey. Such long timescales are difficult to explain with variations driven by the interaction between the disk and stellar magnetic field, which has a dynamical timescale of days to weeks. The most likely explanation is either structural or temperature fluctuations spread throughout the inner ∼0.5 au of the disk, suggesting that the intrinsic dust structure is highly dynamic.

  16. Early GRB optical and infrared afterglow observations with the 2-m robotic Liverpool Telescope

    International Nuclear Information System (INIS)

    Gomboc, A.; Ljubljana Univ., Ljubljana; Mundell, C.G.; Guidorzi, C.

    2005-01-01

    We present the first optical observations of a Gamma Ray Burst IGRB) afterglow using the 2-m robotic Liverpool Telescope (LT), which is owned and operated by Liverpool John Moores University and situated on La Palma. We briefly discuss the capabilities of LT and its suitability for rapid follow-up observations of early optical and infrared GRB light curves. In particular, the combination of aperture, site, instrumentation and rapid response (robotic over-ride mode aided by telescope's rapid slew and fully-opening enclosure) makes the LT ideal for investigating the nature of short bursts, optically-dark bursts, and GRB blast-wave physics in general. We briefly describe the LT's key position in the RoboNet-1.0 network of robotic telescopes. We present the LT observations of GRB041006 and use its gamma-ray properties to predict the time of the break in optical light curve, a prediction consistent with the observations

  17. Electron energetics in the expanding solar wind via Helios observations

    Czech Academy of Sciences Publication Activity Database

    Štverák, Štěpán; Trávníček, Pavel M.; Hellinger, Petr

    2015-01-01

    Roč. 120, č. 10 (2015), s. 8177-8193 ISSN 2169-9380 Institutional support: RVO:68378289 Keywords : solar wind plasma * plasma energization * transport processes Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 3.318, year: 2015 http://onlinelibrary.wiley.com/doi/10.1002/2015JA021368/abstract

  18. Electron energetics in the expanding solar wind via Helios observations

    Czech Academy of Sciences Publication Activity Database

    Štverák, Štěpán; Trávníček, Pavel M.; Hellinger, Petr

    2015-01-01

    Roč. 120, č. 10 (2015), s. 8177-8193 ISSN 2169-9380 R&D Projects: GA ČR GAP209/12/2041; GA ČR GA15-17490S Institutional support: RVO:67985815 Keywords : solar wind * electrons energetics * transport processes Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 3.318, year: 2015

  19. Solar wind charge exchange observed through the lunar exosphere

    Czech Academy of Sciences Publication Activity Database

    Robertson, I. P.; Sembay, S.; Stubbs, T. J.; Kuntz, K. D.; Collier, M. R.; Cravens, T. E.; Snowden, S. L.; Hills, H. K.; Porter, F. S.; Trávníček, Pavel M.; Carter, J. A.; Read, A. M.

    2009-01-01

    Roč. 36, - (2009), L21102/1-L21102/5 ISSN 0094-8276 Institutional research plan: CEZ:AV0Z30420517 Keywords : lunar exosphere * solar wind * X-rays Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 3.204, year: 2009

  20. SORCE and Future Satellite Observations of Solar Irradiance

    Science.gov (United States)

    Cahalan, Robert F.; Rottman, G.; Woods, T.; Lawrence, G.; Kopp, G.; Harder, J.; McClintock, W.

    2003-01-01

    With solar activity just passing the maximum of cycle 23, SORCE is beginning a 5 year mission to measure total solar irradiance (TSI) with unprecedented accuracy using phase-sensitive detection, and to measure spectral solar irradiance (SSI) with unprecedented spectral coverage, from 1 to 2000 nm. The new Total Irradiance Monitor (TIM) has 4 active cavity radiometers, any one of which can be used as a fixed-temperature reference against any other that is exposed to the Sun via a shutter that cycles at a rate designed to minimize noise at the shutter frequency. The new Spectral Irradiance Monitor (SIM) is a dual Fery prism spectrometer that can employ either prism as a monochromatic source on the other prism, thus monitoring its transmission during the mission lifetime. Either prism can measure SSI from 200 to 2000 nm, employing the same phase-sensitive electrical substitution strategy as TIM. SORCE also carries dual SOLSTICE instruments to cover the spectral range 100-320 nm, similar to the instruments onboard UARS, and also an XUV Photometer System (XPS) similar to that on TIMED. SSI has now been added to TSI as a requirement of EOS and NPOESS, because different spectral components drive different components of the climate system - UV into upper atmosphere and stratospheric ozone, IR into tropospheric water vapor and clouds, and Visible into the oceans and biosphere. Succeeding satellite missions being planned for 2006 and 2011 will continue to monitor these critical solar variables.

  1. The magnetic field configuration of a solar prominence inferred from spectropolarimetric observations in the He i 10 830 Å triplet

    Science.gov (United States)

    Orozco Suárez, D.; Asensio Ramos, A.; Trujillo Bueno, J.

    2014-06-01

    Context. Determining the magnetic field vector in quiescent solar prominences is possible by interpreting the Hanle and Zeeman effects in spectral lines. However, observational measurements are scarce and lack high spatial resolution. Aims: We determine the magnetic field vector configuration along a quiescent solar prominence by interpreting spectropolarimetric measurements in the He i 1083.0 nm triplet obtained with the Tenerife Infrared Polarimeter installed at the German Vacuum Tower Telescope of the Observatorio del Teide. Methods: The He i 1083.0 nm triplet Stokes profiles were analyzed with an inversion code that takes the physics responsible for the polarization signals in this triplet into account. The results are put into a solar context with the help of extreme ultraviolet observations taken with the Solar Dynamic Observatory and the Solar Terrestrial Relations Observatory satellites. Results: For the most probable magnetic field vector configuration, the analysis depicts a mean field strength of 7 gauss. We do not find local variations in the field strength except that the field is, on average, lower in the prominence body than in the prominence feet, where the field strength reaches ~25 gauss. The averaged magnetic field inclination with respect to the local vertical is ~77°. The acute angle of the magnetic field vector with the prominence main axis is 24° for the sinistral chirality case and 58° for the dextral chirality. These inferences are in rough agreement with previous results obtained from the analysis of data acquired with lower spatial resolutions. A movie is available in electronic form at http://www.aanda.org

  2. Energy Storage and Release through the Solar Activity Cycle Models Meet Radio Observations

    CERN Document Server

    Nindos, Alexander

    2012-01-01

    For nearly sixty years, radio observations have provided a unique insight into the physics of the active and quiescent solar atmosphere. Thanks to the variety of emission mechanisms and to the large altitude range available to observations, fundamental plasma parameters have been measured from the low chromosphere to the upper corona and interplanetary medium. This book presents current research in solar radio astronomy and shows how well it fits in the exceptional scientific context brought by the current space solar observatories. It essentially contains contributed research and review papers presented during the 2010 Community of European Solar Radio Astronomers (CESRA) meeting, which took place in Belgium in June 2010. This book is aimed at graduate students and researchers working in solar physics and space science. Previously published in Solar Physics journal, Vol. 273/2, 2011.

  3. Solar wind and coronal structure near sunspot minimum - Pioneer and SMM observations from 1985-1987

    Science.gov (United States)

    Mihalov, J. D.; Barnes, A.; Hundhausen, A. J.; Smith, E. J.

    1990-01-01

    Changes in solar wind speed and magnetic polarity observed at the Pioneer spacecraft are discussed here in terms of the changing magnetic geometry implied by SMM coronagraph observations over the period 1985-1987. The pattern of recurrent solar wind streams, the long-term average speed, and the sector polarity of the interplanetary magnetic field all changed in a manner suggesting both a temporal variation, and a changing dependence on heliographic latitude. Coronal observations during this epoch show a systematic variation in coronal structure and the magnetic structure imposed on the expanding solar wind. These observations suggest interpretation of the solar wind speed variations in terms of the familiar model where the speed increases with distance from a nearly flat interplanetary current sheet, and where this current sheet becomes aligned with the solar equatorial plane as sunspot minimum approaches, but deviates rapidly from that orientation after minimum.

  4. Elemental GCR Observations during the 2009-2010 Solar Minimum Period

    Science.gov (United States)

    Lave, K. A.; Israel, M. H.; Binns, W. R.; Christian, E. R.; Cummings, A. C.; Davis, A. J.; deNolfo, G. A.; Leske, R. A.; Mewaldt, R. A.; Stone, E. C.; hide

    2013-01-01

    Using observations from the Cosmic Ray Isotope Spectrometer (CRIS) onboard the Advanced Composition Explorer (ACE), we present new measurements of the galactic cosmic ray (GCR) elemental composition and energy spectra for the species B through Ni in the energy range approx. 50-550 MeV/nucleon during the record setting 2009-2010 solar minimum period. These data are compared with our observations from the 1997-1998 solar minimum period, when solar modulation in the heliosphere was somewhat higher. For these species, we find that the intensities during the 2009-2010 solar minimum were approx. 20% higher than those in the previous solar minimum, and in fact were the highest GCR intensities recorded during the space age. Relative abundances for these species during the two solar minimum periods differed by small but statistically significant amounts, which are attributed to the combination of spectral shape differences between primary and secondary GCRs in the interstellar medium and differences between the levels of solar modulation in the two solar minima. We also present the secondary-to-primary ratios B/C and (Sc+Ti+V)/Fe for both solar minimum periods, and demonstrate that these ratios are reasonably well fit by a simple "leaky-box" galactic transport model that is combined with a spherically symmetric solar modulation model.

  5. Evaluating the Effectiveness of Wildlife Detection and Observation Technologies at a Solar Power Tower Facility.

    Science.gov (United States)

    Diehl, Robert H; Valdez, Ernest W; Preston, Todd M; Wellik, Michael J; Cryan, Paul M

    2016-01-01

    Solar power towers produce electrical energy from sunlight at an industrial scale. Little is known about the effects of this technology on flying animals and few methods exist for automatically detecting or observing wildlife at solar towers and other tall anthropogenic structures. Smoking objects are sometimes observed co-occurring with reflected, concentrated light ("solar flux") in the airspace around solar towers, but the identity and origins of such objects can be difficult to determine. In this observational pilot study at the world's largest solar tower facility, we assessed the efficacy of using radar, surveillance video, and insect trapping to detect and observe animals flying near the towers. During site visits in May and September 2014, we monitored the airspace surrounding towers and observed insects, birds, and bats under a variety of environmental and operational conditions. We detected and broadly differentiated animals or objects moving through the airspace generally using radar and near solar towers using several video imaging methods. Video revealed what appeared to be mostly small insects burning in the solar flux. Also, we occasionally detected birds flying in the solar flux but could not accurately identify birds to species or the types of insects and small objects composing the vast majority of smoking targets. Insect trapping on the ground was somewhat effective at sampling smaller insects around the tower, and presence and abundance of insects in the traps generally trended with radar and video observations. Traps did not tend to sample the larger insects we sometimes observed flying in the solar flux or found dead on the ground beneath the towers. Some of the methods we tested (e.g., video surveillance) could be further assessed and potentially used to automatically detect and observe flying animals in the vicinity of solar towers to advance understanding about their effects on wildlife.

  6. Evaluating the effectiveness of wildlife detection and observation technologies at a solar power tower facility

    Science.gov (United States)

    Diehl, Robert H.; Valdez, Ernest W.; Preston, Todd M.; Wellik, Mike J.; Cryan, Paul

    2016-01-01

    Solar power towers produce electrical energy from sunlight at an industrial scale. Little is known about the effects of this technology on flying animals and few methods exist for automatically detecting or observing wildlife at solar towers and other tall anthropogenic structures. Smoking objects are sometimes observed co-occurring with reflected, concentrated light (“solar flux”) in the airspace around solar towers, but the identity and origins of such objects can be difficult to determine. In this observational pilot study at the world’s largest solar tower facility, we assessed the efficacy of using radar, surveillance video, and insect trapping to detect and observe animals flying near the towers. During site visits in May and September 2014, we monitored the airspace surrounding towers and observed insects, birds, and bats under a variety of environmental and operational conditions. We detected and broadly differentiated animals or objects moving through the airspace generally using radar and near solar towers using several video imaging methods. Video revealed what appeared to be mostly small insects burning in the solar flux. Also, we occasionally detected birds flying in the solar flux but could not accurately identify birds to species or the types of insects and small objects composing the vast majority of smoking targets. Insect trapping on the ground was somewhat effective at sampling smaller insects around the tower, and presence and abundance of insects in the traps generally trended with radar and video observations. Traps did not tend to sample the larger insects we sometimes observed flying in the solar flux or found dead on the ground beneath the towers. Some of the methods we tested (e.g., video surveillance) could be further assessed and potentially used to automatically detect and observe flying animals in the vicinity of solar towers to advance understanding about their effects on wildlife.

  7. Observation of near and intermediate infrared galactic radiation by the rocket K-10-14

    International Nuclear Information System (INIS)

    Hayakawa, Satio; Matsumoto, Toshio; Mizuno, Tomohisa; Murakami, Hiroshi; Noguchi, Kunio

    1981-01-01

    The spatial and the energy spectra of near and intermediate infrared radiation were observed by using a detector system loaded on a rocket. The detector system is a He-cooled infrared telescope, and consists of an optical system, a cryostat, an electronic system, and a star sensor. The system was loaded on the rocket K-10-14, and the observation was made for about 400 second on August 27, 1980. For the radiation with wavelength of 2.4 mu m and 4.6 mu m, the intensity of galactic light around 338, 9, 15 and 12 degree of galactic longitude was observed. For the wavelength of 7.6, 10.1 and 14.7 mu m, the data around 340 and 10 degree of galactic longitude were obtained. The latitudinal distribution of radiation of 2.4 and 4.6 mu m was measured. After the correction for interstellar absorption, it can be said that the galactic radiation of wavelength between 2.4 mu m and 7.6 mu m was mainly composed of the radiation from light balls of late type stars. (Kato, T.)

  8. Optical and infrared observations of SN 1987A from Cerro Tololo Inter-American Observatory

    International Nuclear Information System (INIS)

    Phillips, M.M.

    1988-01-01

    Results from optical and infrared observations of SN 1987A obtained at Cerro Tololo Inter-American Observatory over the first seven months since core collapse are reviewed. Around 130 days after outburst, the bolometric light curve began to smoothly decline at a rate of ∼ 0.01 mag day-1, providing dramatic confirmation of the prediction that radioactivity had powered the optical display after the first month./ the peculiar color changes are kinks observed beginning on the 25th day probably signaled the initial release of trapped energy from mass 56 material. The bolometric luminosity of SN 1987A was unusually low at first, but reached a value more typical of other type II supernovae by the time that the final exponential decline had begun. Over much of the period covered by these observations, the optical and infrared spectra were characterized by strong absorption lines of Ba II and Sr II. Comparison with the spectra of other type II supernovae at similar stages of evolution supports the suggestion that s-processed elements were enriched in the hydrogen envelope of the progenitor, Sanduleak - 69 degrees 202

  9. Solar variability observed through changes in solar figure and mean diameter

    International Nuclear Information System (INIS)

    Hill, H.A.

    1985-01-01

    A program to monitor solar luminosity variations through diameter measurements has been operation at SCLERA since 1981. The solar diameter is currently measured at multiple angles from the equator. Measurements at these different angles have the advantage that, not only can the solar oblateness be accurately measured, but, also, systematic errors, introduced by atmospheric refraction, can be reduced to a minimum. The primary emphasis during the last year has been on data analysis and interpretation. An extension of theoretical work relevant to the relationship between the solar diameter and luminosity for long-period oscillations has been extended to include 160 min period oscillations, and several tests have been completed. An absolute calibration system for the telescope field has been constructed and is being tested. A review of this work is presented

  10. Solar variability observed through changes in solar figure and mean diameter

    International Nuclear Information System (INIS)

    1984-01-01

    A program to monitor solar luminosity variations through diameter measurements has been in operation at SCLERA since 1981. The solar diameter is measured at multiple angles from the equator. Measurements at these different angles have the advantage that not only can the solar oblateness be accurately measured, but also, a systematic errors introduced by atmospheric refraction can be reduced to a minimum. An improved theoretical treatment relevant to the relationship between the solar diameter and luminosity for long period oscilations has been successfully developed, and testing is currently underway. The construction of an absolute calibration system for the telescope field has been conducted and will soon be operational. A review of this work is presented

  11. Spacecraft observations of solar wind turbulence: an overview

    International Nuclear Information System (INIS)

    Horbury, T S; Forman, M A; Oughton, S

    2005-01-01

    Spacecraft measurements in the solar wind offer the opportunity to study magnetohydrodynamic (MHD) turbulence in a collisionless plasma in great detail. We review some of the key results of the study of this medium: the presence of large amplitude Alfven waves propagating predominantly away from the Sun; the existence of an active turbulent cascade; and the presence of intermittency similar to that in neutral fluids. We also discuss the presence of anisotropy in wavevector space relative to the local magnetic field direction. Some models suggest that MHD turbulence can evolve to a state with power predominantly in wavevectors either parallel to the magnetic field ('slab' fluctuations) or approximately perpendicular to it ('2D'). We review the existing evidence for such anisotropy, which has important consequences for the transport of energetic particles. Finally, we present the first results of a new analysis which provides the most accurate measurements to date of the wave-vector anisotropy of wavevector power in solar wind MHD turbulence

  12. MgII Observations Using the MSFC Solar Ultraviolet Magnetograph

    Science.gov (United States)

    West, Edward; Cirtain, Jonathan; Kobayashi, Ken; Davis, John; Gary, Allen; Adams, Mitzi

    2011-01-01

    This paper will describe the scientific goals of our sounding rocket program, the Solar Ultraviolet Magnetograph Investigation (SUMI). This paper will present a brief description of the optics that were developed to meet SUMI's scientific goals, discuss the spectral, spatial and polarization characteristics of SUMI s optics, describe SUMI's flight which was launched 7/30/2010, and discuss what we have learned from that flight.

  13. Adaptive image stabilization of solar observations: A review

    International Nuclear Information System (INIS)

    Von Der Luhe, O.

    1985-01-01

    The purpose of this contribution is to review recent developments of active wave front correction techniques for solar imaging. Experience has shown, that image motion control significantly improves the resolution of typical long exposure applications such as spectrograms and spectroheliograms. Basic IM control systems need only simple technology and, in most cases, are easily implemented in most existing telescopes. Spot trackers are on their way to being routineously used

  14. Solar thermal barometer - EurObserv'ER - May 2010

    International Nuclear Information System (INIS)

    2010-05-01

    In 2008, the European solar thermal market put on a strong spurt only to mark time in 2009 with about 4.2 million m 2 installed, which is 443708 m 2 less year-on-year. The economic crisis has had a ripple effect on the European market in the shape of the Euro crisis at the beginning of May, so the slump seems set to continue on into 2010

  15. CIMEX: a prototype Instrument to observe from space the amazon forest In the near and shortwave infrared

    Science.gov (United States)

    Guerin, François; Dantes, Didier; Savaria, Eric; Selingardi, Mario Luis; Montes, Amauri Silva

    2018-04-01

    This paper, "CIMEX: a prototype Instrument to observe from space the amazon forest In the near and shortwave infrared," was presented as part of International Conference on Space Optics—ICSO 1997, held in Toulouse, France.

  16. Volcanic Eruption Observations from an Elevated Point of the Stromboli Using Thermal Infrared Hyperspectral Imaging

    Science.gov (United States)

    Morton, V.; Gagnon, M. A.; Marcotte, F.; Gouhier, M.; Smekens, J. F.

    2017-12-01

    Many urban areas are located near active volcanoes around the world. Therefore, scientific research on different indicators of imminent eruptions is carried out on an ongoing basis. Due to the hazardous and unpredictable behavior of volcanoes, remote sensing technologies are normally preferred for investigations. Over the years, the Telops Hyper-Cam, a high-performance infrared hyperspectral camera, has established itself as a reference tool for investigating gas clouds over large distances. In order to illustrate the benefits of standoff infrared hyperspectral imaging for characterizing volcanic processes, many different measurements were carried out from an elevated point ( 800 m) of the Stromboli volcano (Italy) by researchers from the Université Blaise-Pascal (Clermont-Ferrand, France). The Stromboli volcano is well known for its periodic eruptions of small magnitude containing various proportions of ash, lava and gases. Imaging was carried out at a relatively high spectral and spatial resolution before and during eruptions from the North-East (NE) craters. Both sulfur dioxide (SO2) and sulfur tetrafluoride (SiF4) could be successfully identified within the volcano's plume from their distinct spectral features. During the passive degassing phase, a total amount of 3.3 kg of SO2 and 0.8 g of SiF4 were estimated. A violent eruption from NE1 crater was then observed and a total of 45 g and and 7 g of SO2 and SiF4 were estimated respectively. These results are in good agreement with previous work using a UV-SO2 camera. Finally, a smaller eruption from NE2 crater was observed. Total amounts of 3 kg and 17 g of SO2 and SiF4 were estimated respectively. Quantitative chemical maps for both gases will be presented. The results show that standoff thermal infrared hyperspectral imaging provides unique insights for a better understanding of volcanic eruptions.

  17. British Observations of the 18 August 1868 Total Solar Eclipse from Guntoor, India

    Science.gov (United States)

    Orchiston, Wayne; Lee, Eun-Hee; Ahn, Young-Sook

    The total solar eclipse of 18 August 1868 was observed in Aden, India, Siam (present-day Thailand) and the Dutch East Indies (present-day Indonesia). One Indian expedition was sponsored by the Royal Astronomical Society, and led by Major J.F. Tennant. In this chapter we describe the observing team and instruments, discuss their observations, and conclude with some remarks on the place of the 1868 eclipse in solar studies and later nineteenth century European astronomical expeditions to India.

  18. Global oscillations of the Sun: observed as oscillations in the apparent solar limb darkening function

    International Nuclear Information System (INIS)

    Hill, H.A.; Caudell, T.P.

    1979-01-01

    Analysis of the 1973 solar oblateness observations made at SCLERA has indicated that most of the oscillatory power found in observations of the apparent solar diameter is statistically significant and that it is produced by fluctuations in the limb darkening function rather than by a simple displacement of the solar limb. The differential refractive effects in the Earth's atmosphere may be ruled out as operative mechanisms for generating the observed oscillations. Solar and non-solar mechanisms for producing changes in the apparent limb darkening function are considered as possible sources of the observed oscillatory effects; it is concluded that acoustic and gravity modes of oscillation are the only viable mechanisms capable of producing these phenomena. This interpretation necessitates the imposition of certain constraints on modelling of the solar interior and on solar pulsation theory. The conclusion that the oscillations are detected through changes in the limb darkening function leads to a new constraint on the photospheric boundary conditions used in pulsation theory. The identification of two of the oscillations as being high-order gravity modes also necessitates the formulation of a new constraint on the Brunt-Vaisalai frequency in the solar interior and, in addition, may place a constraint depth on the convection zone. Application of the constraint on the Brunt-Vaisalai frequency permits discrimination between current models while the first constraint, if correct, may further complicate studies of the outer envelope of the Sun. (author)

  19. Solar wind and coronal structure near sunspot minimum: Pioneer and SMM observations from 1985-1987

    International Nuclear Information System (INIS)

    Mihalov, J.D.; Barnes, A.; Hundhausen, A.J.; Smith, E.J.

    1990-01-01

    The solar wind speeds observed in the outer heliosphere (20 to 40 AU heliocentric distance, approximately) by Pioneers 10 an 11, and at a heliocentric distance of 0.7 AU by the Pioneer Venus spacecraft, reveal a complex set of changes in the years near the recent sunspot minimum, 1985-1987. The pattern of recurrent solar wind streams, the long-term average speed, and the sector polarity of the interplanetary magnetic field all changed in a manner suggesting both a temporal variation, and a changing dependence on heliographic latitude. Coronal observations made from the Solar Maximum Mission spacecraft during the same epoch show a systematic variation in coronal structure and (by implication) the magnetic structure imposed on the expanding solar wind. These observations suggest interpretation of the solar wind speed variations in terms of the familiar model where the speed increases with distance from a nearly flat interplanetary current sheet (or with heliomagnetic latitude), and where this current sheet becomes aligned with the solar equatorial plane as sunspot minimum approaches, but deviates rapidly from that orientation after minimum. The authors confirm here that this basic organization of the solar wind speed persists in the outer heliosphere with an orientation of the neutral sheet consistent with that inferred at a heliocentric distance of a few solar radii, from the coronal observations

  20. Preliminary observations and results obtained with the ultraviolet spectrometer and polarimeter. [for Solar Maximum Mission

    Science.gov (United States)

    Tandberg-Hassen, E.; Cheng, C. C.; Athay, R. G.; Beckers, J. M.; Brandt, J. C.; Chapman, R. D.; Bruner, E. C.; Henze, W.; Hyder, C. L.; Gurman, J. B.

    1981-01-01

    New observation with the Ultraviolet Spectrometer and Polarimeter (UVSP) of a number of manifestations of solar activity obtained during the first three months of Solar Maximum Mission operations are presented. Attention is given to polarimetry in sunspots, oscillations above sunspots, density diagnostics of transition-zone plasmas in active regions, and the eruptive prominence - coronal transient link.

  1. The extreme solar storm of May 1921: observations and a complex topological model

    Directory of Open Access Journals (Sweden)

    H. Lundstedt

    2015-01-01

    Full Text Available A complex solid torus model was developed in order to be able to study an extreme solar storm, the so-called "Great Storm" or "New York Railroad Storm" of May 1921, when neither high spatial and time resolution magnetic field measurements, solar flare nor coronal mass ejection observations were available. We suggest that a topological change happened in connection with the occurrence of the extreme solar storm. The solar storm caused one of the most severe space weather effects ever.

  2. Far-infrared Spectral Radiance Observations and Modeling of Arctic Cirrus: Preliminary Results From RHUBC

    Science.gov (United States)

    Humpage, Neil; Green, Paul D.; Harries, John E.

    2009-03-01

    Recent studies have highlighted the important contribution of the far-infrared (electromagnetic radiation with wavelengths greater than 12 μm) to the Earth's radiative energy budget. In a cloud-free atmosphere, a significant fraction of the Earth's cooling to space from the mid- and upper troposphere takes place via the water vapor pure rotational band between 17 and 33 μm. Cirrus clouds also play an important role in the Earth's outgoing longwave radiation. The effect of cirrus on far-infrared radiation is of particular interest, since the refractive index of ice depends strongly on wavelength in this spectral region. The scattering properties of ice crystals are directly related to the refractive index, so consequently the spectral signature of cirrus measured in the FIR is sensitive to the cloud microphysical properties [1, 2]. By examining radiances measured at wavelengths between the strong water vapor absorption lines in the FIR, the understanding of the relationship between cirrus microphysics and the radiative transfer of thermal energy through cirrus may be improved. Until recently, very few observations of FIR spectral radiances had been made. The Tropospheric Airborne Fourier Transform Spectrometer (TAFTS) was developed by Imperial College to address this lack of observational data. TAFTS observes both zenith and nadir radiances at 0.1 cm-1 resolution, between 80 and 600 cm-1. During February and March 2007, TAFTS was involved in RHUBC (the Radiative Heating in Under-explored Bands Campaign), an ARM funded field campaign based at the ACRF-North Slope of Alaska site near Barrow, situated at 71° latitude. Infrared zenith spectral observations were taken by both TAFTS and the AERI-ER (spectral range 400-3300 cm-1) from the ground during both cloud-free and cirrus conditions. A wide range of other instrumentation was also available at the site, including a micropulse lidar, 35 GHz radar and the University of Colorado/NOAA Ground-based Scanning Radiometer

  3. Observation of a 27-day solar signature in noctilucent cloud altitude

    Science.gov (United States)

    Köhnke, Merlin C.; von Savigny, Christian; Robert, Charles E.

    2018-05-01

    Previous studies have identified solar 27-day signatures in several parameters in the Mesosphere/Lower thermosphere region, including temperature and Noctilucent cloud (NLC) occurrence frequency. In this study we report on a solar 27-day signature in NLC altitude with peak-to-peak variations of about 400 m. We use SCIAMACHY limb-scatter observations from 2002 to 2012 to detect NLCs. The superposed epoch analysis method is applied to extract solar 27-day signatures. A 27-day signature in NLC altitude can be identified in both hemispheres in the SCIAMACHY dataset, but the signature is more pronounced in the northern hemisphere. The solar signature in NLC altitude is found to be in phase with solar activity and temperature for latitudes ≳ 70 ° N. We provide a qualitative explanation for the positive correlation between solar activity and NLC altitude based on published model simulations.

  4. MID-INFRARED SPECTROSCOPIC OBSERVATIONS OF THE DUST-FORMING CLASSICAL NOVA V2676 OPH

    Energy Technology Data Exchange (ETDEWEB)

    Kawakita, Hideyo; Arai, Akira; Shinnaka, Yoshiharu [Koyama Astronomical Observatory, Kyoto Sangyo University, Motoyama, Kamigamo, Kita-ku, Kyoto 603-8555 (Japan); Ootsubo, Takafumi [Department of Earth Science and Astronomy, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902 (Japan); Nagashima, Masayoshi, E-mail: kawakthd@cc.kyoto-su.ac.jp [Department of Physics, Faculty of Science, Kyoto Sangyo University, Motoyama, Kamigamo, Kita-ku, Kyoto 603-8555 (Japan)

    2017-02-01

    The dust-forming nova V2676 Oph is unique in that it was the first nova to provide evidence of C{sub 2} and CN molecules during its near-maximum phase and evidence of CO molecules during its early decline phase. Observations of this nova have revealed the slow evolution of its lightcurves and have also shown low isotopic ratios of carbon ({sup 12}C/{sup 13}C) and nitrogen ({sup 14}N/{sup 15}N) in its envelope. These behaviors indicate that the white dwarf (WD) star hosting V2676 Oph is a CO-rich WD rather than an ONe-rich WD (typically larger in mass than the former). We performed mid-infrared spectroscopic and photometric observations of V2676 Oph in 2013 and 2014 (respectively 452 and 782 days after its discovery). No significant [Ne ii] emission at 12.8 μ m was detected at either epoch. These provided evidence for a CO-rich WD star hosting V2676 Oph. Both carbon-rich and oxygen-rich grains were detected in addition to an unidentified infrared feature at 11.4 μ m originating from polycyclic aromatic hydrocarbon molecules or hydrogenated amorphous carbon grains in the envelope of V2676 Oph.

  5. THE ORIGIN OF THE INFRARED EMISSION IN RADIO GALAXIES. II. ANALYSIS OF MID- TO FAR-INFRARED SPITZER OBSERVATIONS OF THE 2JY SAMPLE

    NARCIS (Netherlands)

    Dicken, D.; Tadhunter, C.; Axon, D.; Morganti, R.; Inskip, K. J.; Holt, J.; Delgado, R. Gonzalez; Groves, B.

    2009-01-01

    We present an analysis of deep mid- to far-infrared (MFIR) Spitzer photometric observations of the southern 2Jy sample of powerful radio sources (0.05

  6. High-energy solar flare observations at the Y2K maximum

    Science.gov (United States)

    Emslie, A. Gordon

    2000-04-01

    Solar flares afford an opportunity to observe processes associated with the acceleration and propagation of high-energy particles at a level of detail not accessible in any other astrophysical source. I will review some key results from previous high-energy solar flare observations, including those from the Compton Gamma-Ray Observatory, and the problems that they pose for our understanding of energy release and particle acceleration processes in the astrophysical environment. I will then discuss a program of high-energy observations to be carried out during the upcoming 2000-2001 solar maximum that is aimed at addressing and resolving these issues. A key element in this observational program is the High Energy Solar Spectroscopic Imager (HESSI) spacecraft, which will provide imaging spectroscopic observations with spatial, temporal, and energy resolutions commensurate with the physical processes believed to be operating, and will in addition provide the first true gamma-ray spectroscopy of an astrophysical source. .

  7. QUANTIFYING THE ANISOTROPY AND SOLAR CYCLE DEPENDENCE OF '1/f' SOLAR WIND FLUCTUATIONS OBSERVED BY ADVANCED COMPOSITION EXPLORER

    International Nuclear Information System (INIS)

    Nicol, R. M.; Chapman, S. C.; Dendy, R. O.

    2009-01-01

    The power spectrum of the evolving solar wind shows evidence of a spectral break between an inertial range (IR) of turbulent fluctuations at higher frequencies and a '1/f' like region at lower frequencies. In the ecliptic plane at ∼1 AU, this break occurs approximately at timescales of a few hours and is observed in the power spectra of components of velocity and magnetic field. The '1/f' energy range is of more direct coronal origin than the IR, and carries signatures of the complex magnetic field structure of the solar corona, and of footpoint stirring in the solar photosphere. To quantify the scaling properties we use generic statistical methods such as generalized structure functions and probability density functions (PDFs), focusing on solar cycle dependence and on anisotropy with respect to the background magnetic field. We present structure function analysis of magnetic and velocity field fluctuations, using a novel technique to decompose the fluctuations into directions parallel and perpendicular to the mean local background magnetic field. Whilst the magnetic field is close to '1/f', we show that the velocity field is '1/f α ' with α ≠ 1. For the velocity, the value of α varies between parallel and perpendicular fluctuations and with the solar cycle. There is also variation in α with solar wind speed. We have examined the PDFs in the fast, quiet solar wind and intriguingly, whilst parallel and perpendicular are distinct, both the B field and velocity show the same PDF of their perpendicular fluctuations, which is close to gamma or inverse Gumbel. These results point to distinct physical processes in the corona and to their mapping out into the solar wind. The scaling exponents obtained constrain the models for these processes.

  8. Synoptic maps of solar wind parameters from in situ spacecraft observations

    Science.gov (United States)

    Gazis, P. R.

    1995-01-01

    Solar wind observations from the Interplanetary Monitoring Platform-8 (IMP-8) and Pioneer Venus Orbiter (PVO) spacecraft from 1982 until 1988 are combined to construct synoptic maps of solar wind parameters near 1 AU. Each map consists of 6 months of hourly averaged solar wind data, binned by heliographic latitude and Carrington longitude and projected back to the Sun. These maps show the structure and time evolution of solar wind streams near 1 AU in the heliographic latitudes of +/- 7.25 deg and provide and explicit picture of several phenomena, such as gradients, changes in the inclination of the heliospheric current sheet, and the relative positions of various structures in the inner heliosphere, that is difficult to obtain from single-spacecraft observations. The stream structure varied significantly during the last solar cycle. Between 1982 and early 1985, solar wind parameters did not depend strongly on heliographic latitude. During the last solar minimum, the solar wind developed significant latitudinal structure, and high-speed streams were excluded from the vicinity of the solar equator. The interplanetary magnetic field was strongly correlated with the coronal field, and the current sheet tended to coincide with the coronal neutral line. The solar wind speed showed the expected correlations with temperature, interplanetary magnetic field, and distance from the current sheet. The solar wind speed was anticorrelated with density, but the regions of highest density occurred east of the heliospheric current sheet and the regions of lowest solar wind speed. This is consistent with compression at the leading edge of high-speed streams.

  9. Ultraviolet, X-ray, and infrared observations of HDE 226868 equals Cygnus X-1

    Science.gov (United States)

    Treves, A.; Chiappetti, L.; Tanzi, E. G.; Tarenghi, M.; Gursky, H.; Dupree, A. K.; Hartmann, L. W.; Raymond, J.; Davis, R. J.; Black, J.

    1980-01-01

    During April, May, and July of 1978, HDE 226868, the optical counterpart of Cygnus X-1, was repeatedly observed in the ultraviolet with the IUE satellite. Some X-ray and infrared observations have been made during the same period. The general shape of the spectrum is that expected from a late O supergiant. Strong absorption features are apparent in the ultraviolet, some of which have been identified. The equivalent widths of the most prominent lines appear to be modulated with the orbital phase. This modulation is discussed in terms of the ionization contours calculated by Hatchett and McCray, for a binary X-ray source in the stellar wind of the companion.

  10. Infrared observations of HDE 226868/Cyg X-1 and HDE 245770/AO535+26

    International Nuclear Information System (INIS)

    Persi, P.; Toniolo, M.F.; Spada, G.

    1979-01-01

    It is known from Copernicus ultraviolet observations that all O type stars are losing mass by stellar wind. The ionized expanding circumstellar envelope formed by the stellar wind is emitting through free-free and bound-free radiation processes. This radiation is detectable at the infrared wavelengths where the stellar continuum is negligible. The measurement of the IR excess (defined as the difference between the total flux and the stellar continuum at a given wavelength) and the knowledge of the terminal velocity of the envelope, allow one to derive for OB stars the mass loss rate. From the analysis of Ir observations of two O stars, HDE 226868 and HDE 245770, identified as optical counterpart of X-ray sources, an estimate is given of their mass loss rate. (Auth.)

  11. Far-infrared and CO observations of NGC 6357 and regions surrounding NGC 6357 and NGC 6334

    International Nuclear Information System (INIS)

    McBreen, B.; Jaffe, D.T.; Fazio, G.G.

    1983-01-01

    We have surveyed two 1.7 square degree sections of the galactic plane at 70 μm with one-arcminute resolution. The scanned areas included the giant southern H II region complexes NGC 6357 and NGC 6334. Nineteen far-infrared sources were observed. The sources range in luminosity from 1.6 x 10 4 to 5.5 x 10 5 L/sub sun/ . We present far-infrared continuum and CO line observations of NGC 6357. Four far-infrared sources were found in this complex and for one of these sources the exciting stars are identified. We present far-infrared and CO observations of sources in the field surrounding NGC 6357 and NGC 6334. The far-infrared sources coincide frequently with CO line temperature peaks. The CO clouds which surround the far-infrared sources have similar 13 CO column densities. Two of the far-infrared sources in the field have associated OH and H 2 O maser emission and compact H II regions

  12. Ultradeep Near-Infrared ISAAC Observations of the Hubble Deep Field South: Observations, Reduction, Multicolor Catalog, and Photometric Redshifts

    Science.gov (United States)

    Labbé, Ivo; Franx, Marijn; Rudnick, Gregory; Schreiber, Natascha M. Förster; Rix, Hans-Walter; Moorwood, Alan; van Dokkum, Pieter G.; van der Werf, Paul; Röttgering, Huub; van Starkenburg, Lottie; van der Wel, Arjen; Kuijken, Konrad; Daddi, Emanuele

    2003-03-01

    We present deep near-infrared (NIR) Js-, H-, and Ks-band ISAAC imaging of the Wide Field Planetary Camera 2 (WFPC2) field of the Hubble Deep Field South (HDF-S). The 2.5‧×2.5‧ high Galactic latitude field was observed with the Very Large Telescope under the best seeing conditions, with integration times amounting to 33.6 hr in Js, 32.3 hr in H, and 35.6 hr in Ks. We reach total AB magnitudes for point sources of 26.8, 26.2, and 26.2, respectively (3 σ), which make it the deepest ground-based NIR observation to date and the deepest Ks-band data in any field. The effective seeing of the co-added images is ~0.45" in Js, ~0.48" in H, and ~0.46" in Ks. Using published WFPC2 optical data, we constructed a Ks-limited multicolor catalog containing 833 sources down to Ktots,AB2.3 (in Johnson magnitudes). Because they are extremely faint in the observed optical, they would be missed by ultraviolet-optical selection techniques, such as the U-dropout method. Based on service mode observations collected at the European Southern Observatory, Paranal, Chile (ESO Program 164.O-0612). Also based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy (AURA), Inc., under NASA contract NAS 5-26555.

  13. Observations of Fe XIV Line Intensity Variations in the Solar Corona During the 21 August 2017 Solar Eclipse

    Science.gov (United States)

    Johnson, Payton; Ladd, Edwin

    2018-01-01

    We present time- and spatially-resolved observations of the inner solar corona in the 5303 Å line of Fe XIV, taken during the 21 August 2017 solar eclipse from a field observing site in Crossville, TN. These observations are used to characterize the intensity variations in this coronal emission line, and to compare with oscillation predictions from models for heating the corona by magnetic wave dissipation.The observations were taken with two Explore Scientific ED 102CF 102 mm aperture triplet apochromatic refractors. One system used a DayStar custom-built 5 Å FWHM filter centered on the Fe XIV coronal spectral line and an Atik Titan camera for image collection. The setup produced images with a pixel size of 2.15 arcseconds (~1.5 Mm at the distance to the Sun), and a field of view of 1420 x 1060 arcseconds, covering approximately 20% of the entire solar limb centered near the emerging sunspot complex AR 2672. We obtained images with an exposure time of 0.22 seconds and a frame rate of 2.36 Hz, for a total of 361 images during totality.An identical, co-aligned telescope/camera system observed the same portion of the solar corona, but with a 100 Å FWHM Baader Planetarium solar continuum filter centered on a wavelength of 5400 Å. Images with an exposure time of 0.01 seconds were obtained with a frame rate of 4.05 Hz. These simultaneous observations are used as a control to monitor brightness variations not related to coronal line oscillations.

  14. Solar Polar Field Observed by SOHO/MDI and Hinode

    Science.gov (United States)

    Liu, Y.

    2009-12-01

    Using 1-minute cadence time-series full disk magnetograms taken by SOHO/MDI in 2007 March, and the corresponding Hinode/SOT vector magnetograms, I have studied evolutionary characteristics of magnetic elements in Sun's south polar region in solar minimum. It is found that the lifetime of magnetic elements is 17.0 hours on average with an average lifetime of 21.8 hours for elements with positive field, the dominant polarity in the south pole, and 1.6 hours for elements with negative field. The elements with positive field are dominant in the south pole with a percentage of 76% in element number and 90.5% in magnetic flux. The lifetime and magnetic flux of the elements is found to be highly related. This agrees with some previous studies for the elements in low latitude quiet regions. Using an image cross correlation method, I also measure solar rotation rate at high latitude, up to 85° in latitude, which is ω = 2.914-0.342 × sin2φ-0.482×sin4φ μrad/s sidereal. It agrees with previous studies using spectroscopic and image cross correlation methods, and also agrees with the results from some work using the element tracking method in which the sample of tracked elements is large. The consistency of those results from different data and methods strongly suggests that this rate at high latitude is reliable.

  15. Observations & modeling of solar-wind/magnetospheric interactions

    Science.gov (United States)

    Hoilijoki, Sanni; Von Alfthan, Sebastian; Pfau-Kempf, Yann; Palmroth, Minna; Ganse, Urs

    2016-07-01

    The majority of the global magnetospheric dynamics is driven by magnetic reconnection, indicating the need to understand and predict reconnection processes and their global consequences. So far, global magnetospheric dynamics has been simulated using mainly magnetohydrodynamic (MHD) models, which are approximate but fast enough to be executed in real time or near-real time. Due to their fast computation times, MHD models are currently the only possible frameworks for space weather predictions. However, in MHD models reconnection is not treated kinetically. In this presentation we will compare the results from global kinetic (hybrid-Vlasov) and global MHD simulations. Both simulations are compared with in-situ measurements. We will show that the kinetic processes at the bow shock, in the magnetosheath and at the magnetopause affect global dynamics even during steady solar wind conditions. Foreshock processes cause an asymmetry in the magnetosheath plasma, indicating that the plasma entering the magnetosphere is not symmetrical on different sides of the magnetosphere. Behind the bow shock in the magnetosheath kinetic wave modes appear. Some of these waves propagate to the magnetopause and have an effect on the magnetopause reconnection. Therefore we find that kinetic phenomena have a significant role in the interaction between the solar wind and the magnetosphere. While kinetic models cannot be executed in real time currently, they could be used to extract heuristics to be added in the faster MHD models.

  16. Solar flares observed simultaneously with SphinX, GOES and RHESSI

    Science.gov (United States)

    Mrozek, Tomasz; Gburek, Szymon; Siarkowski, Marek; Sylwester, Barbara; Sylwester, Janusz; Kępa, Anna; Gryciuk, Magdalena

    2013-07-01

    In February 2009, during recent deepest solar minimum, Polish Solar Photometer in X-rays (SphinX) begun observations of the Sun in the energy range of 1.2-15 keV. SphinX was almost 100 times more sensitive than GOES X-ray Sensors. The silicon PIN diode detectors used in the experiment were carefully calibrated on the ground using Synchrotron Radiation Source BESSY II. The SphinX energy range overlaps with the Ramaty High Energy Solar Spectroscopic Imager (RHESSI) energy range. The instrument provided us with observations of hundreds of very small flares and X-ray brightenings. We have chosen a group of solar flares observed simultaneously with GOES, SphinX and RHESSI and performed spectroscopic analysis of observations wherever possible. The analysis of thermal part of the spectra showed that SphinX is a very sensitive complementary observatory for RHESSI and GOES.

  17. Single-step colloidal quantum dot films for infrared solar harvesting

    KAUST Repository

    Kiani, Amirreza; Sutherland, Brandon R.; Kim, Younghoon; Ouellette, Olivier; Levina, Larissa; Walters, Grant; Dinh, Cao Thang; Liu, Mengxia; Voznyy, Oleksandr; Lan, Xinzheng; Labelle, Andre J.; Ip, Alexander H.; Proppe, Andrew; Ahmed, Ghada H.; Mohammed, Omar F.; Hoogland, Sjoerd; Sargent, Edward H.

    2016-01-01

    . To date, IR CQD solar cells have been made using a wasteful and complex sequential layer-by-layer process. Here, we demonstrate ∼1 eV bandgap solar-harvesting CQD films deposited in a single step. By engineering a fast-drying solvent mixture for metal

  18. An analysis of vibration-rotation lines of OH in the solar infrared spectrum

    NARCIS (Netherlands)

    Grevesse, N.; Sauval, A.J.; Dishoeck, van E.F.

    1984-01-01

    High resolution solar spectra have permitted the measurement with great accuracy of equivalent widths of vibration-rotation lines of OH in the X2Pi state near 3-micron wavelength. Using recent theoretical results for the transition probabilities, a solar oxygen abundance of (8.93 + or - 0.02) is

  19. Measurements of size and composition of particles in polar stratospheric clouds from infrared solar absorption spectra

    International Nuclear Information System (INIS)

    Kinne, S.; Toon, O.B.; Toon, G.C.; Farmer, C.B.; Browell, E.V.; McCormick, M.P.

    1989-01-01

    The attenuation of solar radiation between 1.8- and 15-μm wavelength was measured with the airborne Jet Propulsion Laboratory Mark IV interferometer during the Airborne Antarctic Ozone Expedition in 1987. The measurements not only provide information about the abundance of stratospheric gases, but also about the optical depths of polar stratospheric clouds (PSCs) at wavelengths of negligible gas absorption. The spectral dependence of the PSC optical depth contains information about PSC particle size and particle composition. Thirty-three PSC cases were analyzed and categorized into two types. Type I clouds contain particles with radii of about 0.5 μm and nitric acid concentrations greater than 40%. Type II clouds contain particles composed of water ice with radii of 6 μm and larger. Cloud altitudes were determined from 1.064-μm backscattering observations of the airborne Langley DIAL lidar system. Based on the PSC geometrical thickness, both mass and particle density were estimated. Type I clouds typically had visible wavelength optical depths of about 0.008, mass densities of about 20 ppb, and about 2 particles/cm 3 . The observed type II clouds had optical depths of about 0.03, mass densities of about 400 ppb mass, and about 0.03 particles/cm 3 . The detected PSC type I clouds extended to altitudes of 21 km and were nearly in the ozone-depleted region of the polar stratosphere. The observed type II cases during September were predominantly found at altitudes below 15 km

  20. Wide-Field Infrared Survey Explorer Observations of the Evolution of Massive Star-Forming Regions

    Science.gov (United States)

    Koenig, X. P.; Leisawitz, D. T.; Benford, D. J.; Rebull, L. M.; Padgett, D. L.; Asslef, R. J.

    2012-01-01

    We present the results of a mid-infrared survey of II outer Galaxy massive star-forming regions and 3 open clusters with data from the Wide-field Infrared Survey Explorer (WISE). Using a newly developed photometric scheme to identify young stellar objects and exclude extragalactic contamination, we have studied the distribution of young stars within each region. These data tend to support the hypothesis that latter generations may be triggered by the interaction of winds and radiation from the first burst of massive star formation with the molecular cloud material leftover from that earlier generation of stars. We dub this process the "fireworks hypothesis" since star formation by this mechanism would proceed rapidly and resemble a burst of fireworks. We have also analyzed small cutout WISE images of the structures around the edges of these massive star-forming regions. We observe large (1-3 pc size) pillar and trunk-like structures of diffuse emission nebulosity tracing excited polycyclic aromatic hydrocarbon molecules and small dust grains at the perimeter of the massive star-forming regions. These structures contain small clusters of emerging Class I and Class II sources, but some are forming only a single to a few new stars.

  1. WIDE-FIELD INFRARED SURVEY EXPLORER OBSERVATIONS OF THE EVOLUTION OF MASSIVE STAR-FORMING REGIONS

    International Nuclear Information System (INIS)

    Koenig, X. P.; Leisawitz, D. T.; Benford, D. J.; Padgett, D. L.; Rebull, L. M.; Assef, R. J.

    2012-01-01

    We present the results of a mid-infrared survey of 11 outer Galaxy massive star-forming regions and 3 open clusters with data from the Wide-field Infrared Survey Explorer (WISE). Using a newly developed photometric scheme to identify young stellar objects and exclude extragalactic contamination, we have studied the distribution of young stars within each region. These data tend to support the hypothesis that latter generations may be triggered by the interaction of winds and radiation from the first burst of massive star formation with the molecular cloud material leftover from that earlier generation of stars. We dub this process the 'fireworks hypothesis' since star formation by this mechanism would proceed rapidly and resemble a burst of fireworks. We have also analyzed small cutout WISE images of the structures around the edges of these massive star-forming regions. We observe large (1-3 pc size) pillar and trunk-like structures of diffuse emission nebulosity tracing excited polycyclic aromatic hydrocarbon molecules and small dust grains at the perimeter of the massive star-forming regions. These structures contain small clusters of emerging Class I and Class II sources, but some are forming only a single to a few new stars.

  2. Cyclotron Line in Solar Microwave Radiation by Radio Telescope RATAN-600 Observations of the Solar Active Region NOAA 12182

    Science.gov (United States)

    Peterova, N. G.; Topchilo, N. A.

    2017-12-01

    This paper presents the results of observation of a rare phenomenon—a narrowband increase in the brightness of cyclotron radiation of one of the structural details of a radio source located in the solar corona above the solar active region NOAA 12182 in October 2014 at a frequency of 4.2 ± 0.1 GHz. The brightness of radiation in the maximum of the phenomenon has reached 10 MK; its duration was equal to 3 s. The exact location of the source of the narrowband cyclotron radiation is indicated: it is a corona above a fragmented (4-nuclear) sunspot, on which a small UV flare loop was closed.

  3. THE NEW HORIZONS SOLAR WIND AROUND PLUTO (SWAP) OBSERVATIONS OF THE SOLAR WIND FROM 11–33 au

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, H. A.; McComas, D. J.; Valek, P.; Weidner, S.; Livadiotis, G. [Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78238 (United States); Nicolaou, G., E-mail: helliott@swri.edu [Swedish Institute of Space Physics, Box 812, SE-98128, Kiruna (Sweden)

    2016-04-15

    The Solar Wind Around Pluto (SWAP) instrument on National Aeronautics and Space Administration's New Horizons Pluto mission has collected solar wind observations en route from Earth to Pluto, and these observations continue beyond Pluto. Few missions have explored the solar wind in the outer heliosphere making this dataset a critical addition to the field. We created a forward model of SWAP count rates, which includes a comprehensive instrument response function based on laboratory and flight calibrations. By fitting the count rates with this model, the proton density (n), speed (V), and temperature (T) parameters are determined. Comparisons between SWAP parameters and both propagated 1 au observations and prior Voyager 2 observations indicate consistency in both the range and mean wind values. These comparisons as well as our additional findings confirm that small and midsized solar wind structures are worn down with increasing distance due to dynamic interaction of parcels of wind with different speed. For instance, the T–V relationship steepens, as the range in V is limited more than the range in T with distance. At times the T–V correlation clearly breaks down beyond 20 au, which may indicate wind currently expanding and cooling may have an elevated T reflecting prior heating and compression in the inner heliosphere. The power of wind parameters at shorter periodicities decreases with distance as the longer periodicities strengthen. The solar rotation periodicity is present in temperature beyond 20 au indicating the observed parcel temperature may reflect not only current heating or cooling, but also heating occurring closer to the Sun.

  4. THE NEW HORIZONS SOLAR WIND AROUND PLUTO (SWAP) OBSERVATIONS OF THE SOLAR WIND FROM 11–33 au

    International Nuclear Information System (INIS)

    Elliott, H. A.; McComas, D. J.; Valek, P.; Weidner, S.; Livadiotis, G.; Nicolaou, G.

    2016-01-01

    The Solar Wind Around Pluto (SWAP) instrument on National Aeronautics and Space Administration's New Horizons Pluto mission has collected solar wind observations en route from Earth to Pluto, and these observations continue beyond Pluto. Few missions have explored the solar wind in the outer heliosphere making this dataset a critical addition to the field. We created a forward model of SWAP count rates, which includes a comprehensive instrument response function based on laboratory and flight calibrations. By fitting the count rates with this model, the proton density (n), speed (V), and temperature (T) parameters are determined. Comparisons between SWAP parameters and both propagated 1 au observations and prior Voyager 2 observations indicate consistency in both the range and mean wind values. These comparisons as well as our additional findings confirm that small and midsized solar wind structures are worn down with increasing distance due to dynamic interaction of parcels of wind with different speed. For instance, the T–V relationship steepens, as the range in V is limited more than the range in T with distance. At times the T–V correlation clearly breaks down beyond 20 au, which may indicate wind currently expanding and cooling may have an elevated T reflecting prior heating and compression in the inner heliosphere. The power of wind parameters at shorter periodicities decreases with distance as the longer periodicities strengthen. The solar rotation periodicity is present in temperature beyond 20 au indicating the observed parcel temperature may reflect not only current heating or cooling, but also heating occurring closer to the Sun

  5. Pioneer and Voyager observations of the solar wind at large heliocentric distances and latitudes

    Science.gov (United States)

    Gazis, P. R.; Mihalov, J. D.; Barnes, A.; Lazarus, A. J.; Smith, E. J.

    1989-01-01

    Data obtained from the electrostatic analyzers aboard the Pioneer 10 and 11 spacecraft and from the Faraday cup aboard Voyager 2 were used to study spatial gradients in the distant solar wind. Prior to mid-1985, both spacecraft observed nearly identical solar wind structures. After day 150 of 1985, the velocity structure at Voyager 2 became flatter, and the Voyager 2 velocities were smaller than those observed by Pioneer 11. It is suggested that these changes in the solar wind at low latitudes may be related to a change which occurred in the coronal hole structure in early 1985.

  6. Improved upper bounds on Kaluza-Klein gravity with current Solar System experiments and observations

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Xue-Mei [Chinese Academy of Sciences, Purple Mountain Observatory, Nanjing (China); Xie, Yi [Nanjing University, School of Astronomy and Space Science, Nanjing (China); Shanghai Key Laboratory of Space Navigation and Position Techniques, Shanghai (China); Nanjing University, Ministry of Education, Key Laboratory of Modern Astronomy and Astrophysics, Nanjing (China)

    2015-11-15

    As an extension of previous works on classical tests of Kaluza-Klein (KK) gravity and as an attempt to find more stringent constraints on this theory, its effects on physical experiments and astronomical observations conducted in the Solar System are studied. We investigate the gravitational time delay at inferior conjunction caused by KK gravity, and use new Solar System ephemerides and the observation of Cassini to strengthen constraints on KK gravity by up to two orders of magnitude. These improved upper bounds mean that the fifth-dimensional space in the soliton case is a very flat extra dimension in the Solar System, even in the vicinity of the Sun. (orig.)

  7. Infrared Observations of the Orion Capsule During EFT-1 Hypersonic Reentry

    Science.gov (United States)

    Horvath, Thomas J.; Rufer, Shann J.; Schuster, David M.; Mendeck, Gavin F.; Oliver, A. Brandon; Schwartz, Richard J.; Verstynen, Harry A.; Mercer, C. David; Tack, Steven; Ingram, Ben; hide

    2016-01-01

    High-resolution infrared observations of the Orion capsule during its atmospheric reentry on December 5, 2015 were made from a US Navy NP-3D. This aircraft, equipped with a long-range optical sensor system, tracked the capsule from Mach 10 to 7 from a distance of approximately 60 nmi. Global surface temperatures of the capsule's thermal heatshield were derived from near infrared intensity measurements. The global surface temperature measurements complemented onboard instrumentation and were invaluable to the interpretation of the in-depth thermocouple measurements which rely on inverse heat transfer methods and material response codes to infer the desired surface temperature from the sub-surface measurements. The full paper will address the motivations behind the NASA Engineering Safety Center sponsored observation and highlight premission planning processes with an emphasis on aircraft placement, optimal instrument configuration and sensor calibrations. Critical aspects of mission operations coordinated from the NASA Johnson Spaceflight Center and integration with the JSC Flight Test Management Office will be discussed. A summary of the imagery that was obtained and processed to global surface temperature will be presented. At the capsule's point of closest approach relative to the imaging system, the spatial resolution was estimated to be approximately 15-inches per pixel and was sufficient to identify localized temperature increases associated with compression pad support hardware on the heatshield. The full paper will discuss the synergy of the quantitative imagery derived temperature maps with in-situ thermocouple measurements. Comparison of limited onboard surface thermocouple data to the image derived surface temperature will be presented. The two complimentary measurements serve as an example of the effective leveraging of resources to advance the understanding of high Mach number environments associated with an ablated heatshield and provide unique data

  8. A global climatology of stratospheric gravity waves from Atmospheric Infrared Sounder observations

    Science.gov (United States)

    Hoffmann, Lars; Xue, Xianghui; Alexander, M. Joan

    2014-05-01

    We present the results of a new study that aims on the detection and classification of `hotspots' of stratospheric gravity waves on a global scale. The analysis is based on a nine-year record (2003 to 2011) of radiance measurements by the Atmospheric Infrared Sounder (AIRS) aboard NASA's Aqua satellite. We detect the presence of stratospheric gravity waves based on 4.3 micron brightness temperature variances. Our method is optimized for peak events, i.e., strong gravity wave events for which the local variance considerably exceeds background levels. We estimated the occurrence frequencies of these peak events for different seasons and time of day and used the results to find local maxima of gravity wave activity. In addition, we use AIRS radiances at 8.1 micron to simultaneously detect convective events, including deep convection in the tropics and mesoscale convective systems at mid latitudes. We classified the gravity waves according to their sources, based on seasonal occurrence frequencies for convection and by means of topographic data. Our study reproduces well-known hotspots of gravity waves, e.g., the mountain wave hotspots at the Andes and the Antarctic Peninsula or the convective hotspot during the thunderstorm season over the North American Great Plains. However, the high horizontal resolution of the AIRS observations also helped us to locate several smaller hotspots, which were partly unknown or poorly studied so far. Most of these smaller hotspots are found near orographic features like small mountain ranges, in coastal regions, in desert areas, or near isolated islands. This new study will help to select the most promising regions and seasons for future observational studies of gravity waves. Reference: Hoffmann, L., X. Xue, and M. J. Alexander, A global view of stratospheric gravity wave hotspots located with Atmospheric Infrared Sounder observations, J. Geophys. Res., 118, 416-434, doi:10.1029/2012JD018658, 2013.

  9. Efficient perovskite/organic integrated solar cells with extended photoresponse to 930 nm and enhanced near-infrared external quantum efficiency of over 50.

    Science.gov (United States)

    Guo, Qiang; Liu, Hao; Shi, Zhenzhen; Wang, Fuzhi; Zhou, Erjun; Bian, Xingming; Zhang, Bing; Alsaedi, Ahmed; Hayat, Tasawar; Tan, Zhan'ao

    2018-02-15

    Enhancing the light-harvesting activity is an effective way to improve the power conversion efficiency of solar cells. Although rapid enhancement in the PCE up to a value of 22.1% has been achieved for perovskite solar cells, only part of the sunlight, i.e., with wavelengths below 800-850 nm is utilized due to the limited bandgap of the perovskite materials, resulting in most of the near infrared light being wasted. To broaden the photoresponse of perovskite solar cells, we demonstrate an efficient perovskite/organic integrated solar cell containing both CH 3 NH 3 PbI 3 perovskite and PBDTTT-E-T:IEICO organic photoactive layers. By integrating a low band gap PBDTTT-E-T:IEICO active layer on a perovskite layer, the maximum wavelength for light harvesting of the ISC increased to 930 nm, sharply increasing the utilization of near infrared radiation. In addition, the external quantum efficiency of the integrated device exceeded 50% in the near infrared range. The MAPbI 3 /PBDTTT-E-T:IEICO ISCs show an enhanced short-circuit current density of over 24 mA cm -2 , which is the highest existing value among perovskite/organic integrated solar cells and much higher than the traditional MAPbI 3 based perovskite solar cells. The results reveal that a perovskite/organic integrated structure is a promising strategy to extend and enhance sunlight utilization for perovskite solar cells.

  10. Magnetospheric and solar physics observations with the PAMELA experiment

    International Nuclear Information System (INIS)

    Casolino, M.; Adriani, O.; Ambriola, M.; Barbarino, G.C.; Basili, A.; Bazilevskaja, G.A.; Boezio, M.; Bogomolov, E.A.; Bonechi, L.; Bongi, M.; Bonvicini, V.; Bruno, A.; Cafagna, F.; Campana, D.; Carlson, P.; Castellini, G.

    2008-01-01

    PAMELA is a satellite-borne experiment designed to make long duration measurements of the cosmic radiation in Low Earth Orbit. It is devoted to the detection of the cosmic-ray spectra in the 100 MeV-300 GeV range with primary scientific goal the measurement of antiproton and positron spectra over the largest energy range ever achieved. Other tasks include the search for antinuclei with unprecedented sensitivity and the measurement of the light nuclear component of cosmic rays. In addition, PAMELA can investigate phenomena connected with solar and Earth physics. The apparatus consists of: a Time of Flight system, a magnetic spectrometer, an electromagnetic imaging calorimeter, a shower tail catcher scintillator, a neutron detector and an anticoincidence system. In this work we present some measurements of galactic, secondary and trapped particles performed in the first months of operation

  11. Magnetospheric and solar physics observations with the PAMELA experiment

    Energy Technology Data Exchange (ETDEWEB)

    Casolino, M. [INFN, Structure of Rome ' Tor Vergata' and Physics Department of University of Rome ' Tor Vergata' , Via della Ricerca Scientifica 1, I-00133 Rome (Italy)], E-mail: Marco.Casolino@roma2.infn.it; Adriani, O. [INFN, Structure of Florence and Physics Department of University of Florence, Via Sansone 1, I-50019 Sesto Fiorentino, Florence (Italy); Ambriola, M. [INFN, Structure of Bari and Physics Department of University of Bari, Via Amendola 173, I-70126 Bari (Italy); Barbarino, G.C. [INFN, Structure of Naples and Physics Department of University of Naples ' Federico II' , Via Cintia, I-80126 Naples (Italy); Basili, A. [INFN, Structure of Rome ' Tor Vergata' and Physics Department of University of Rome ' Tor Vergata' , Via della Ricerca Scientifica 1, I-00133 Rome (Italy); Bazilevskaja, G.A. [Lebedev Physical Institute, Leninsky Prospekt 53, RU-119991 Moscow (Russian Federation); Boezio, M. [INFN, Structure of Trieste and Physics Department of University of Trieste, Via A. Valerio 2, I-34127 Trieste (Italy); Bogomolov, E.A. [Ioffe Physical Technical Institute, Polytekhnicheskaya 26, RU-194021 St. Petersburg (Russian Federation); Bonechi, L.; Bongi, M. [INFN, Structure of Florence and Physics Department of University of Florence, Via Sansone 1, I-50019 Sesto Fiorentino, Florence (Italy); Bonvicini, V. [INFN, Structure of Trieste and Physics Department of University of Trieste, Via A. Valerio 2, I-34127 Trieste (Italy); Bruno, A.; Cafagna, F. [INFN, Structure of Bari and Physics Department of University of Bari, Via Amendola 173, I-70126 Bari (Italy); Campana, D. [INFN, Structure of Naples and Physics Department of University of Naples ' Federico II' , Via Cintia, I-80126 Naples (Italy); Carlson, P. [KTH, Department of Physics, Albanova University Centre, SE-10691 Stockholm (Sweden); Castellini, G. [IFAC, Via Madonna del Piano 10, I-50019 Sesto Fiorentino, Florence (Italy)] (and others)

    2008-04-01

    PAMELA is a satellite-borne experiment designed to make long duration measurements of the cosmic radiation in Low Earth Orbit. It is devoted to the detection of the cosmic-ray spectra in the 100 MeV-300 GeV range with primary scientific goal the measurement of antiproton and positron spectra over the largest energy range ever achieved. Other tasks include the search for antinuclei with unprecedented sensitivity and the measurement of the light nuclear component of cosmic rays. In addition, PAMELA can investigate phenomena connected with solar and Earth physics. The apparatus consists of: a Time of Flight system, a magnetic spectrometer, an electromagnetic imaging calorimeter, a shower tail catcher scintillator, a neutron detector and an anticoincidence system. In this work we present some measurements of galactic, secondary and trapped particles performed in the first months of operation.

  12. OBSERVATIONS OF THE HELIOSHEATH AND SOLAR WIND NEAR THE TERMINATION SHOCK BY VOYAGER 2

    International Nuclear Information System (INIS)

    Burlaga, L. F.; Ness, N. F.; Acuna, M. H.; Richardson, J. D.; Stone, E.; McDonald, F. B.

    2009-01-01

    This paper describes the principal features of 24 hr averages of the magnetic field strength variations B(t) and their relationships to the plasma and energetic particles observed prior to and after the crossing of the termination shock (TS) by Voyager 2 (V2). The solar wind (pre-TS crossing) and heliosheath (post-TS crossing) data extend from day of year (DOY) 1 through 241, 2007 and from 2007 DOY 245 through 2008 DOY 80, respectively. In the solar wind, two merged interaction regions (MIRs) were observed in which the ratio of plasma pressure to magnetic pressure in the solar wind was relatively low. Strong magnetic fields and low values of beta were also observed just prior to its crossing of the TS. The predicted correlation between peaks in the intensity of energetic particles in the solar wind when V2 crossed the heliospheric current sheet from positive to negative magnetic polarity in the solar wind was not observed. In the heliosheath, V2 observed a feature characterized by large enhancements of the density N and the proton temperature T, a small increase in speed V, and a depression in B. The distributions of 24 hr averages of B and beta were approximately log-normal in both the solar wind and the heliosheath. A unipolar region was observed for 73 days in the heliosheath, as the heliospheric current sheet moved toward the equatorial plane to latitudes lower than V2.

  13. DEEP SPITZER OBSERVATIONS OF INFRARED-FAINT RADIO SOURCES: HIGH-REDSHIFT RADIO-LOUD ACTIVE GALACTIC NUCLEI?

    International Nuclear Information System (INIS)

    Norris, Ray P.; Mao, Minnie; Afonso, Jose; Cava, Antonio; Farrah, Duncan; Oliver, Seb; Huynh, Minh T.; Mauduit, Jean-Christophe; Surace, Jason; Ivison, R. J.; Jarvis, Matt; Lacy, Mark; Maraston, Claudia; Middelberg, Enno; Seymour, Nick

    2011-01-01

    Infrared-faint radio sources (IFRSs) are a rare class of objects which are relatively bright at radio wavelengths but very faint at infrared and optical wavelengths. Here we present sensitive near-infrared observations of a sample of these sources taken as part of the Spitzer Extragalactic Representative Volume Survey. Nearly all the IFRSs are undetected at a level of ∼1 μJy in these new deep observations, and even the detections are consistent with confusion with unrelated galaxies. A stacked image implies that the median flux density is S 3.6μm ∼ 0.2 μJy or less, giving extreme values of the radio-infrared flux density ratio. Comparison of these objects with known classes of object suggests that the majority are probably high-redshift radio-loud galaxies, possibly suffering from significant dust extinction.

  14. Germanium blocked impurity band far infrared detectors

    International Nuclear Information System (INIS)

    Rossington, C.S.

    1988-04-01

    The infrared portion of the electromagnetic spectrum has been of interest to scientist since the eighteenth century when Sir William Herschel discovered the infrared as he measured temperatures in the sun's spectrum and found that there was energy beyond the red. In the late nineteenth century, Thomas Edison established himself as the first infrared astronomer to look beyond the solar system when he observed the star Arcturus in the infrared. Significant advances in infrared technology and physics, long since Edison's time, have resulted in many scientific developments, such as the Infrared Astronomy Satellite (IRAS) which was launched in 1983, semiconductor infrared detectors for materials characterization, military equipment such as night-vision goggles and infrared surveillance equipment. It is now planned that cooled semiconductor infrared detectors will play a major role in the ''Star Wars'' nuclear defense scheme proposed by the Reagan administration

  15. Multi-viewpoint Smartphone AR-based Learning System for Solar Movement Observations

    Directory of Open Access Journals (Sweden)

    Ke Tian

    2014-06-01

    Full Text Available Understanding solar movement (e.g., solar diurnal motion is difficult for those are beginning to learn about astronomy. Previous research has revealed that observation-based learning can help make astronomical phenomena clearer to understand for such learners. In this research, Smartphone Augmented Reality (AR technology and 3D content were used to develop a multi-viewpoint Smartphone AR-based learning system (M-VSARLS for solar movement observations that can be used in the real-world environment. The goal of this research is to assess the usefulness of the system, usability of the AR function and 3D content, and the overall effect of the system on the learner’s motivation through task-based experiments with follow-up questionnaires. The results show that the M-VSARL system is effective in improving the observational skills and learning ability of learners, and in enhancing their motivation to learn about solar movement.

  16. Infrared speckle observations of Io - an eruption in the Loki region

    International Nuclear Information System (INIS)

    Howell, R.R.; Mcginn, M.T.

    1985-01-01

    Speckle observations of Jupiter's satellite Io at a wavelength of 5 micrometers during July 1984 resolved the disk and showed emission from a hot spot in the Loki region. The hot spot contributed a flux approximately equal to 60 percent of that from the disk.Images reconstructed by means of the Knox-Thompson algorithm showed the spot moving across the disk as the satellite rotated. It was located at 301 deg + or - 6 deg west longitude, 10 deg + or - 6 deg north latitude, and had a radiance of (2.96 + or - 0.54) x 10 to the 22nd ergs/sec cm sr/A where A is the area of the spot. For an assumed temperature of 400 K, the area of the source would be 11,400 square kilometers. An active lava lake similar to that seen by Voyager may be the source of the infrared emission. 10 references

  17. Application of an automatic cloud tracking technique to Meteosat water vapor and infrared observations

    Science.gov (United States)

    Endlich, R. M.; Wolf, D. E.

    1980-01-01

    The automatic cloud tracking system was applied to METEOSAT 6.7 micrometers water vapor measurements to learn whether the system can track the motions of water vapor patterns. Data for the midlatitudes, subtropics, and tropics were selected from a sequence of METEOSAT pictures for 25 April 1978. Trackable features in the water vapor patterns were identified using a clustering technique and the features were tracked by two different methods. In flat (low contrast) water vapor fields, the automatic motion computations were not reliable, but in areas where the water vapor fields contained small scale structure (such as in the vicinity of active weather phenomena) the computations were successful. Cloud motions were computed using METEOSAT infrared observations (including tropical convective systems and midlatitude jet stream cirrus).

  18. AN INTERFEROMETRIC STUDY OF THE FOMALHAUT INNER DEBRIS DISK. II. KECK NULLER MID-INFRARED OBSERVATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Mennesson, B.; Serabyn, E.; Colavita, M. M. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena CA 91109-8099 (United States); Absil, O. [Departement d' Astrophysique, Geophysique et Oceanographie, Universite de Liege, 17 Allee du Six Aout, B-4000 Sart Tilman (Belgium); Lebreton, J.; Augereau, J.-C. [IPAG, UMR 5274, CNRS and Universite Joseph Fourier, BP 53, F-38041 Grenoble (France); Millan-Gabet, R. [Michelson Science Center, California Institute of Technology, 770 South Wilson Avenue, Pasadena CA 91125 (United States); Liu, W. [Infrared Processing and Analysis Center, California Institute of Technology, Mail Code 100-22, Pasadena, CA 91125 (United States); Hinz, P. [Steward Observatory, University of Arizona, 933 N Cherry Avenue, Tucson, AZ 85721 (United States); Thebault, P. [Observatoire de Paris, Section de Meudon, F-92195 Meudon Principal Cedex (France)

    2013-02-15

    We report on high-contrast mid-infrared observations of Fomalhaut obtained with the Keck Interferometer Nuller (KIN) showing a small resolved excess over the level expected from the stellar photosphere. The measured null excess has a mean value of 0.35% {+-} 0.10% between 8 and 11 {mu}m and increases from 8 to 13 {mu}m. Given the small field of view of the instrument, the source of this marginal excess must be contained within 2 AU of Fomalhaut. This result is reminiscent of previous VLTI K-band ({approx_equal}2{mu}m) observations, which implied the presence of a {approx}0.88% excess, and argued that thermal emission from hot dusty grains located within 6 AU from Fomalhaut was the most plausible explanation. Using a parametric two-dimensional radiative transfer code and a Bayesian analysis, we examine different dust disk structures to reproduce both the near- and mid-infrared data simultaneously. While not a definitive explanation of the hot excess of Fomalhaut, our model suggests that the most likely inner few AU disk geometry consists of a two-component structure, with two different and spatially distinct grain populations. The 2-11 {mu}m data are consistent with an inner hot ring of very small ({approx_equal}10-300 nm) carbon-rich grains concentrating around 0.1 AU. The second dust population-inferred from the KIN data at longer mid-infrared wavelengths-consists of larger grains (size of a few microns to a few tens of microns) located further out in a colder region where regular astronomical silicates could survive, with an inner edge around 0.4 AU-1 AU. From a dynamical point of view, the presence of the inner concentration of submicron-sized grains is surprising, as such grains should be expelled from the inner planetary system by radiation pressure within only a few years. This could either point to some inordinate replenishment rates (e.g., many grazing comets coming from an outer reservoir) or to the existence of some braking mechanism preventing the grains

  19. Midcourse Space Experiment Observations of Small Solar System Bodies

    Science.gov (United States)

    Kraemer, Kathleen E.; Lisse, C. M.; Price, Stephan D.; Mizuno, D.; Walker, R. G.; Farnham, T. L.; Mäkinen, T.

    2005-11-01

    Eight comets, two transition objects (extinct comet candidates), and two near-Earth asteroids were imaged in four infrared bands with the SPIRIT III instrument on the Midcourse Space Experiment, namely, C/1996 B2 (Hyakutake), C/1995 O1 (Hale-Bopp), C/1996 Q1 (Tabur), 126P/IRAS, 22P/Kopff, 46P/Wirtanen, (3200) Phaethon, (4015) 107P/Wilson-Harrington, (4179) Toutatis, (4197) 1982 TA, 125P/Spacewatch, and 55P/Tempel-Tuttle. We present maps of each object detected and a description of their characteristics. Five of the comets had extended dust tails, all of which show evidence for silicate emission in the 8.3 μm band. The comet C/Hyakutake had a strong secondary dust tail along the direction of the comet's motion, which the dynamical models showed was consistent with emission from large particles. The dust trail from P/Kopff was detected more than 2° from the coma in three of the four bands and is probably composed of large particles emitted during the 1996 apparition.

  20. Near-infrared spectroscopic observations of massive young stellar object candidates in the central molecular zone

    Science.gov (United States)

    Nandakumar, G.; Schultheis, M.; Feldmeier-Krause, A.; Schödel, R.; Neumayer, N.; Matteucci, F.; Ryde, N.; Rojas-Arriagada, A.; Tej, A.

    2018-01-01

    Context. The central molecular zone (CMZ) is a 200 pc region around the Galactic centre. The study of star formation in the central part of the Milky Way is of great interest as it provides a template for the closest galactic nuclei. Aims: We present a spectroscopic follow-up of photometrically selected young stellar object (YSO) candidates in the CMZ of the Galactic centre. Our goal is to quantify the contamination of this YSO sample by reddened giant stars with circumstellar envelopes and to determine the star formation rate (SFR) in the CMZ. Methods: We obtained KMOS low-resolution near-infrared spectra (R 4000) between 2.0 and 2.5 μm of sources, many of which have been previously identified by mid-infrared photometric criteria as massive YSOs in the Galactic centre. Our final sample consists of 91 stars with good signal-to-noise ratio. We separated YSOs from cool late-type stars based on spectral features of CO and Brγ at 2.3 μm and 2.16 μm, respectively. We made use of spectral energy distribution (SED) model fits to the observed photometric data points from 1.25 to 24 μm to estimate approximate masses for the YSOs. Results: Using the spectroscopically identified YSOs in our sample, we confirm that existing colour-colour diagrams and colour-magnitude diagrams are unable to efficiently separate YSOs and cool late-type stars. In addition, we define a new colour-colour criterion that separates YSOs from cool late-type stars in the H-KS vs. H -[8.0] diagram. We use this new criterion to identify YSO candidates in the |l| rate than predicted by various star forming models. Based on observations collected at the European Southern Observatory, Chile, programme number 097.C-0208(A).

  1. Advanced fire observation by the Intelligent Infrared Sensor prototype FOCUS on the International Space Station

    Science.gov (United States)

    Oertel, D.; Haschberger, P.; Tank, V.; Lanzl, F.; Zhukov, B.; Jahn, H.; Briess, K.; Lorenz, E.; Roeser, H.-P.; Ginati, A.; Tobehn, C.; Schulte in den Bäumen, J.; Christmann, U.

    1999-01-01

    Current and planned operational space-borne Earth observation systems provide spatially, radiometrically or temporally crude data for the detection and monitoring of high temperature phenomena on the surface of our planet. High Temperature Events (HTE) very often cause environmental disasters. Such HTE are forest and savannah fires, fires of open coal mines, volcanic activities and others (e.g. fires of oil wells, pipelines etc.). A simultaneous co-registration of a combination of infrared (IR) and visible (VIS) channels is the key for a reliable autonomous on-board detection of High Temperature Events (HTE) on Earth surface, such as vegetation fires and volcano eruptions. This is the main feature of the FOCUS experiment. Furthermore there are ecology-oriented objectives of the FOCUS experiment mainly related to spectrometric/imaging remote inspection and parameter extraction of selected HTEs, and to the assessment of some ecological consequences of HTEs, such as aerosol and gas emission. Based on own experimental work and supported by Co-Investigators from Italy, Greece, France, Spain, Russia and Germany, DLR proposed in 1997 to use the International Space Station (ISS) in its early utilization phase as a platform and test-bed for an Intelligent Infrared Sensor prototype FOCUS of a future Environmental Disaster Recognition Satellite System. FOCUS is considered by ESA as an important mission combining a number of proven technologies and observation techniques to provide the scientific and operational user community with key data for the classification and monitoring of forest fires. FOCUS was selected as one of five European ``Groupings'' to be flown as an externally mounted payload during the early utilisation phase of the ISS. The FOCUS Phase A Study will be performed by OHB-System, DLR and Zeiss from September 1998 until May 1999.

  2. Observation and calculation of the solar radiation on the Tibetan Plateau

    International Nuclear Information System (INIS)

    Liu Jiandong; Liu Jingmiao; Linderholm, Hans W.; Chen Deliang; Yu Qiang; Wu Dingrong; Haginoya, Shigenori

    2012-01-01

    Highlights: ► Five years of continuous solar-radiation observations on the Tibetan Plateau were analyzed. ► Eight solar models were calibrated and validated in this highland region. ► A strategy for calculating solar radiation on the Tibetan Plateau was presented. - Abstract: Distribution of solar radiation is vital to locate the most suitable regions for harvesting solar energy, but solar radiation is only observed at few stations due to high costs and difficult maintenance. From 2001 to 2005, a set of pyranometer instruments were set up in Gaize, on the Tibetan Plateau, to test the hypothesis of high solar-radiation levels in this region, and find a suitable method for estimating the radiation. Over the 5-year observation period, the average daily radiation was 21 MJ m −2 day −1 with maximum daily values of 27 MJ m −2 day −1 occurring in June and minimum values of 14 MJ m −2 day −1 in December, which is much higher than those measured in other regions at similar latitudes. The observational data were used to validate a set of radiation models: five sunshine based and three temperature based. The results showed that of the five sunshine-based models, a newly developed “comprehensive” model performed the best, but that the “vapor revised Angstrom model” was recommended to use for its simplicity and easy operation. The temperature-based models performed worse than the sunshine-based ones, where the Wu model is to be preferred if a temperature-based model is the only option. Moreover, it was shown that when estimating the solar radiation based on time-dependent coefficients, consideration of the seasonal variation of the coefficients has little predictive value and is thus unnecessary. Based on the results of this study, a strategy for the calculation of solar radiation on the Tibetan Plateau was made for potential users.

  3. ROSAT Observations of Solar Wind Charge Exchange with the Lunar Exosphere

    Science.gov (United States)

    Collier, Michael R.; Snowden, S. L.; Benna, M.; Carter, J. A.; Cravens, T. E.; Hills, H. Kent; Hodges, R. R.; Kuntz, K. D.; Porter, F. Scott; Read, A.; hide

    2012-01-01

    We analyze the ROSAT PSPC soft X-ray image of the Moon taken on 29 June 1990 by examining the radial profile of the count rate in three wedges, two wedges (one north and one south) 13-32 degrees off (19 degrees wide) the terminator towards the dark side and one wedge 38 degrees wide centered on the anti-solar direction. The radial profiles of both the north and the south wedges show substantial limb brightening that is absent in the 38 degree wide antisolar wedge. An analysis of the count rate increase associated with the limb brightening shows that its magnitude is consistent with that expected due to solar wind charge exchange (SWCX) with the tenuous lunar atmosphere. Along with Mars, Venus, and Earth, the Moon represents another solar system body at which solar wind charge exchange has been observed. This technique can be used to explore the solar wind-lunar interaction.

  4. Statistical and observational research of solar flare for total spectra and geometrical features

    Science.gov (United States)

    Nishimoto, S.; Watanabe, K.; Imada, S.; Kawate, T.; Lee, K. S.

    2017-12-01

    Impulsive energy release phenomena such as solar flares, sometimes affect to the solar-terrestrial environment. Usually, we use soft X-ray flux (GOES class) as the index of flare scale. However, the magnitude of effect to the solar-terrestrial environment is not proportional to that scale. To identify the relationship between solar flare phenomena and influence to the solar-terrestrial environment, we need to understand the full spectrum of solar flares. There is the solar flare irradiance model named the Flare Irradiance Spectral Model (FISM) (Chamberlin et al., 2006, 2007, 2008). The FISM can estimate solar flare spectra with high wavelength resolution. However, this model can not express the time evolution of emitted plasma during the solar flare, and has low accuracy on short wavelength that strongly effects and/or controls the total flare spectra. For the purpose of obtaining the time evolution of total solar flare spectra, we are performing statistical analysis of the electromagnetic data of solar flares. In this study, we select solar flare events larger than M-class from the Hinode flare catalogue (Watanabe et al., 2012). First, we focus on the EUV emission observed by the SDO/EVE. We examined the intensities and time evolutions of five EUV lines of 55 flare events. As a result, we found positive correlation between the "soft X-ray flux" and the "EUV peak flux" for all EVU lines. Moreover, we found that hot lines peaked earlier than cool lines of the EUV light curves. We also examined the hard X-ray data obtained by RHESSI. When we analyzed 163 events, we found good correlation between the "hard X-ray intensity" and the "soft X-ray flux". Because it seems that the geometrical features of solar flares effect to those time evolutions, we also looked into flare ribbons observed by SDO/AIA. We examined 21 flare events, and found positive correlation between the "GOES duration" and the "ribbon length". We also found positive correlation between the "ribbon

  5. MAGNETIC AND DYNAMICAL PHOTOSPHERIC DISTURBANCES OBSERVED DURING AN M3.2 SOLAR FLARE

    Energy Technology Data Exchange (ETDEWEB)

    Kuckein, C. [Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, D-14482, Potsdam (Germany); Collados, M.; Sainz, R. Manso, E-mail: ckuckein@aip.de [Instituto de Astrofísica de Canarias (IAC), Vía Láctea s/n, E-38205, La Laguna, Tenerife (Spain)

    2015-02-01

    This Letter reports on a set of full-Stokes spectropolarimetric observations in the near-infrared He i 10830 Å spectral region covering the pre-flare, flare, and post-flare phases of an M3.2 class solar flare. The flare originated on 2013 May 17 and belonged to active region NOAA 11748. We detected strong He i 10830 Å emission in the flare. The red component of the He i triplet peaks at an intensity ratio to the continuum of about 1.86. During the flare, He i Stokes V is substantially larger and appears reversed compared to the usually larger Si i Stokes V profile. The photospheric Si i inversions of the four Stokes profiles reveal the following: (1) the magnetic field strength in the photosphere decreases or is even absent during the flare phase, as compared to the pre-flare phase. However, this decrease is not permanent. After the flare, the magnetic field recovers its pre-flare configuration in a short time (i.e., 30 minutes after the flare). (2) In the photosphere, the line of sight velocities show a regular granular up- and downflow pattern before the flare erupts. During the flare, upflows (blueshifts) dominate the area where the flare is produced. Evaporation rates of ∼10{sup −3} and ∼10{sup −4} g cm{sup −2} s{sup −1} have been derived in the deep and high photosphere, respectively, capable of increasing the chromospheric density by a factor of two in about 400 s.

  6. Fabrication of thin-film thermoelectric generators with ball lenses for conversion of near-infrared solar light

    Science.gov (United States)

    Ito, Yoshitaka; Mizoshiri, Mizue; Mikami, Masashi; Kondo, Tasuku; Sakurai, Junpei; Hata, Seiichi

    2017-06-01

    We designed and fabricated thin-film thermoelectric generators (TEGs) with ball lenses, which separated visible light and near-infrared (NIR) solar light using a chromatic aberration. The transmitted visible light was used as daylight and the NIR light was used for thermoelectric generation. Solar light was estimated to be separated into the visible light and NIR light by a ray tracing method. 92.7% of the visible light was used as daylight and 9.9% of the NIR light was used for thermoelectric generation. Then, the temperature difference of the pn junctions of the TEG surface was 0.71 K, determined by heat conduction analysis using a finite element method. The thin-film TEGs were fabricated using lithography and deposition processes. When the solar light (A.M. 1.5) was irradiated to the TEGs, the open-circuit voltage and maximum power were 4.5 V/m2 and 51 µW/m2, respectively. These TEGs are expected to be used as an energy supply for Internet of Things sensors.

  7. Dust impact on surface solar irradiance assessed with model simulations, satellite observations and ground-based measurements

    Science.gov (United States)

    Kosmopoulos, Panagiotis G.; Kazadzis, Stelios; Taylor, Michael; Athanasopoulou, Eleni; Speyer, Orestis; Raptis, Panagiotis I.; Marinou, Eleni; Proestakis, Emmanouil; Solomos, Stavros; Gerasopoulos, Evangelos; Amiridis, Vassilis; Bais, Alkiviadis; Kontoes, Charalabos

    2017-07-01

    This study assesses the impact of dust on surface solar radiation focussing on an extreme dust event. For this purpose, we exploited the synergy of AERONET measurements and passive and active satellite remote sensing (MODIS and CALIPSO) observations, in conjunction with radiative transfer model (RTM) and chemical transport model (CTM) simulations and the 1-day forecasts from the Copernicus Atmosphere Monitoring Service (CAMS). The area of interest is the eastern Mediterranean where anomalously high aerosol loads were recorded between 30 January and 3 February 2015. The intensity of the event was extremely high, with aerosol optical depth (AOD) reaching 3.5, and optical/microphysical properties suggesting aged dust. RTM and CTM simulations were able to quantify the extent of dust impact on surface irradiances and reveal substantial reduction in solar energy exploitation capacity of PV and CSP installations under this high aerosol load. We found that such an extreme dust event can result in Global Horizontal Irradiance (GHI) attenuation by as much as 40-50 % and a much stronger Direct Normal Irradiance (DNI) decrease (80-90 %), while spectrally this attenuation is distributed to 37 % in the UV region, 33 % in the visible and around 30 % in the infrared. CAMS forecasts provided a reliable available energy assessment (accuracy within 10 % of that obtained from MODIS). Spatially, the dust plume resulted in a zonally averaged reduction of GHI and DNI of the order of 150 W m-2 in southern Greece, and a mean increase of 20 W m-2 in the northern Greece as a result of lower AOD values combined with local atmospheric processes. This analysis of a real-world scenario contributes to the understanding and quantification of the impact range of high aerosol loads on solar energy and the potential for forecasting power generation failures at sunshine-privileged locations where solar power plants exist, are under construction or are being planned.

  8. Himawari-8 infrared observations of the June-August 2015 Mt Raung eruption, Indonesia

    Science.gov (United States)

    Kaneko, Takayuki; Takasaki, Kenji; Maeno, Fukashi; Wooster, Martin J.; Yasuda, Atsushi

    2018-05-01

    Volcanic activity involves processes that can change over short periods of time, which are sometimes closely related to the eruptive mode or the timing of its transitions. Eruptions bring high-temperature magma or gas to the surface; thermal observations of these eruptions can be used to determine the timeline of eruptive sequences or eruptive processes. In 2014, a new-generation meteorological satellite, Himawari-8, which carried a new sensor, the Advanced Himawari Imager (AHI), was launched. The AHI makes high-frequency infrared observations at a spatial resolution of 2 km during 10-min observation cycles. We analyzed an effusive eruption that occurred in 2015 at Mt Raung in Indonesia using these AHI images, which was the first attempt applying them to volcanological study. Based on the detailed analysis of the time-series variations in its thermal anomalies, this eruptive sequence was segmented into a Precursory Stage, Pulse 1, Pulse 2 and a Terminal Stage. Pulses 1 and 2 are effusive stages that exhibited a consecutive two-pulse pattern in their variations, reflecting changes in the lava effusion rate; the other stages are non-effusive. We were also able to determine the exact times of the onset and reactivation of lava flow effusion, as well as the precursory signals that preceded these events.

  9. Spatially resolved near infrared observations of Enceladus' tiger stripe eruptions from Cassini VIMS

    Science.gov (United States)

    Dhingra, Deepak; Hedman, Matthew M.; Clark, Roger N.; Nicholson, Philip D.

    2017-08-01

    Particle properties of individual fissure eruptions within Enceladus' plume have been analyzed using high spatial resolution Visible and Infrared Mapping Spectrometer (VIMS) observations from the Cassini mission. To first order, the spectra of the materials emerging from Cairo, Baghdad and Damascus sulci are very similar, with a strong absorption band around 3 μm due to water-ice. The band minimum position indicates that the ice grains emerging from all the fissures are predominantly crystalline, which implies that the water-ice particles' formation temperatures are likely above 130 K. However, there is also evidence for subtle variations in the material emerging from the different source fissures. Variations in the spectral slope between 1-2.5 μm are observed and probably reflect differences in the size distributions of particles between 0.5 and 5 μm in radius. We also note variations in the shape of the 3 μm water-ice absorption band, which are consistent with differences in the relative abundance of > 5 μm particles. These differences in the particle size distribution likely reflect variations in the particle formation conditions and/or their transport within the fissures. These observations therefore provide strong motivation for detailed modeling to help place important constraints on the diversity of the sub-surface environmental conditions at the geologically active south-pole of Enceladus.

  10. High-Resolution Infrared Spectroscopic Observations of the Upper Scorpius Eclipsing Binary EPIC 203868608

    Science.gov (United States)

    Johnson, Marshall C.; Mace, Gregory N.; Kim, Hwihyun; Kaplan, Kyle; McLane, Jacob; Sokal, Kimberly R.

    2017-06-01

    EPIC 203868608 is a source in the ~10 Myr old Upper Scorpius OB association. Using K2 photometry and ground-based follow-up observations, David et al. (2016) found that it consists of two brown dwarfs with a tertiary object at a projected separation of ~20 AU; the former objects appear to be a double-lined eclipsing binary with a period of 4.5 days. This is one of only two known eclipsing SB2s where both components are below the hydrogen-burning limit. We present additional follow-up observations of this system from the IGRINS high-resolution near-infrared spectrograph at McDonald Observatory. Our measured radial velocities do not follow the orbital solution presented by David et al. (2016). Instead, our combined IGRINS plus literature radial velocity dataset appears to indicate a period significantly different than that of the eclipsing binary obvious from the K2 light curve. We will discuss possible scenarios to account for the conflicting observations of this system.

  11. High resolution radio observations of nuclear and circumnuclear regions of luminous infrared galaxies (LIRGs)

    Energy Technology Data Exchange (ETDEWEB)

    Alberdi, A; Perez-Torres, M A [Instituto de Astrofisica de Andalucia (IAA, CSIC), PO Box 3004, 18080-Granada (Spain); Colina, L [Instituto de Estructura de la Materia - IEM, CSIC, C, Serrano 115, 28005 Madrid (Spain); Torrelles, J M [Instituto de Ciencias del Espacio (ICE, CSIC) and IEEC, Gran Capita 2-4, 08034 Barcelona (Spain)], E-mail: antxon@iaa.es, E-mail: torres@iaa.es, E-mail: colina@damir.iem.csic.es, E-mail: torrelle@ieec.fcr.es

    2008-10-15

    High-resolution radio observations of the nuclear region of Luminous and Ultraluminous Infrared Galaxies (ULIRGs) have shown that its radio structure consists of a compact high surface-brightness central radio source immersed in a diffuse low brightness circumnuclear halo. While the central component could be associated with an AGN or compact star-forming regions where radio supernovae are exploding, it is well known that the circumnuclear regions host bursts of star-formation. The studies of radio supernovae can provide essential information about stellar evolution and CSM/ISM properties in regions hidden by dust at optical and IR wavelengths. In this contribution, we show results from radio interferometric observations from NGC 7469, IRAS 18293-3413 and IRAS 17138-1017 where three extremely bright radio supernovae have been found. High-resolution radio observations of these and other LIRGs would allow us to determine the core-collapse supernova rate in them as well as their star-formation rate.

  12. The solar wind neon abundance observed with ACE/SWICS and ULYSSES/SWICS

    International Nuclear Information System (INIS)

    Shearer, Paul; Raines, Jim M.; Lepri, Susan T.; Thomas, Jonathan W.; Gilbert, Jason A.; Landi, Enrico; Zurbuchen, Thomas H.; Von Steiger, Rudolf

    2014-01-01

    Using in situ ion spectrometry data from ACE/SWICS, we determine the solar wind Ne/O elemental abundance ratio and examine its dependence on wind speed and evolution with the solar cycle. We find that Ne/O is inversely correlated with wind speed, is nearly constant in the fast wind, and correlates strongly with solar activity in the slow wind. In fast wind streams with speeds above 600 km s –1 , we find Ne/O = 0.10 ± 0.02, in good agreement with the extensive polar observations by Ulysses/SWICS. In slow wind streams with speeds below 400 km s –1 , Ne/O ranges from a low of 0.12 ± 0.02 at solar maximum to a high of 0.17 ± 0.03 at solar minimum. These measurements place new and significant empirical constraints on the fractionation mechanisms governing solar wind composition and have implications for the coronal and photospheric abundances of neon and oxygen. The results are made possible by a new data analysis method that robustly identifies rare elements in the measured ion spectra. The method is also applied to Ulysses/SWICS data, which confirms the ACE observations and extends our view of solar wind neon into the three-dimensional heliosphere.

  13. The solar wind neon abundance observed with ACE/SWICS and ULYSSES/SWICS

    Energy Technology Data Exchange (ETDEWEB)

    Shearer, Paul; Raines, Jim M.; Lepri, Susan T.; Thomas, Jonathan W.; Gilbert, Jason A.; Landi, Enrico; Zurbuchen, Thomas H. [Department of Atmospheric, Oceanic, and Space Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Von Steiger, Rudolf [International Space Science Institute, Hallerstrasse 6, CH-3012 Bern (Switzerland)

    2014-07-01

    Using in situ ion spectrometry data from ACE/SWICS, we determine the solar wind Ne/O elemental abundance ratio and examine its dependence on wind speed and evolution with the solar cycle. We find that Ne/O is inversely correlated with wind speed, is nearly constant in the fast wind, and correlates strongly with solar activity in the slow wind. In fast wind streams with speeds above 600 km s{sup –1}, we find Ne/O = 0.10 ± 0.02, in good agreement with the extensive polar observations by Ulysses/SWICS. In slow wind streams with speeds below 400 km s{sup –1}, Ne/O ranges from a low of 0.12 ± 0.02 at solar maximum to a high of 0.17 ± 0.03 at solar minimum. These measurements place new and significant empirical constraints on the fractionation mechanisms governing solar wind composition and have implications for the coronal and photospheric abundances of neon and oxygen. The results are made possible by a new data analysis method that robustly identifies rare elements in the measured ion spectra. The method is also applied to Ulysses/SWICS data, which confirms the ACE observations and extends our view of solar wind neon into the three-dimensional heliosphere.

  14. Observations of micro-turbulence in the solar wind near the sun with interplanetary scintillation

    Science.gov (United States)

    Yamauchi, Y.; Misawa, H.; Kojima, M.; Mori, H.; Tanaka, T.; Takaba, H.; Kondo, T.; Tokumaru, M.; Manoharan, P. K.

    1995-01-01

    Velocity and density turbulence of solar wind were inferred from interplanetary scintillation (IPS) observations at 2.3 GHz and 8.5 GHz using a single-antenna. The observations were made during September and October in 1992 - 1994. They covered the distance range between 5 and 76 solar radii (Rs). We applied the spectrum fitting method to obtain a velocity, an axial ratio, an inner scale and a power-law spectrum index. We examined the difference of the turbulence properties near the Sun between low-speed solar wind and high-speed solar wind. Both of solar winds showed acceleration at the distance range of 10 - 30 Rs. The radial dependence of anisotropy and spectrum index did not have significant difference between low-speed and high-speed solar winds. Near the sun, the radial dependence of the inner scale showed the separation from the linear relation as reported by previous works. We found that the inner scale of high-speed solar wind is larger than that of low-speed wind.

  15. Voyager observations of solar wind proton temperature - 1-10 AU

    Science.gov (United States)

    Gazis, P. R.; Lazarus, A. J.

    1982-01-01

    Simultaneous measurements are made of the solar wind proton temperatures by the Voyager 1 and 2 spacecraft, far from earth, and the IMP 8 spacecraft in earth orbit. This technique permits a separation of radial and temporal variations of solar wind parameters. The average value of the proton temperature between 1 and 9 AU is observed to decrease as r (the heliocentric radius) to the -(0.7 + or - 0.2). This is slower than would be expected for adiabatic expansion. A detailed examination of the solar wind stream structure shows that considerable heating occurs at the interface between high and low speed streams.

  16. Observation of solar hydrogen Ly-αline with the K-10-12 rocket

    International Nuclear Information System (INIS)

    Koshio, Takafumi; Masuoka, Toshio; Tono, Ichiro; Watanabe, Norihiko.

    1976-01-01

    The purpose of the observation is to perform the absolute irradiance measurement of the solar hydrogen Ly-α line (1216 A 0 ) in the exosphere. The solar hydrogen Ly-α line is emitted from the chromosphere, and contributes to the ionization in the lower ionosphere. The ionization chamber was used for the detection of the solar hydrogen Ly-α line. The K-10-9 rocket was launched on Jan. 18, 1976. The irradiance of the solar hydrogen Ly-α line was measured in the exosphere, and the height distribution of O 2 density was studied on the basis of the absorbancy of the HLy-α line. The result was in good agreement with the previously observed results. (Yoshimori, M.)

  17. Observer-Based Bilinear Control of First-Order Hyperbolic PDEs: Application to the Solar Collector

    KAUST Repository

    Mechhoud, Sarra

    2015-12-18

    In this paper, we investigate the problem of bilinear control of a solar collector plant using the available boundary and solar irradiance measurements. The solar collector is described by a first-order 1D hyperbolic partial differential equation where the pump volumetric flow rate acts as the plant control input. By combining a boundary state observer and an internal energy-based control law, a nonlinear observer based feedback controller is proposed. With a feed-forward control term, the effect of the solar radiation is cancelled. Using the Lyapunov approach we prove that the proposed control guarantees the global exponential stability of both the plant and the tracking error. Simulation results are provided to illustrate the performance of the proposed method.

  18. Common observations of solar X-rays from SPHINX/CORONAS-PHOTON and XRS/MESSENGER

    Science.gov (United States)

    Kepa, Anna; Sylwester, Janusz; Sylwester, Barbara; Siarkowski, Marek; Mrozek, Tomasz; Gryciuk, Magdalena; Phillips, Kenneth

    SphinX was a soft X-ray spectrophotometer constructed in the Space Research Centre of Polish Academy of Sciences. The instrument was launched on 30 January 2009 aboard CORONAS-PHOTON satellite as a part of TESIS instrument package. SphinX measured total solar X-ray flux in the energy range from 1 to 15 keV during the period of very low solar activity from 20 February to 29 November 2009. For these times the solar detector (X-ray Spectrometer - XRS) onboard MESSENGER also observed the solar X-rays from a different vantage point. XRS measured the radiation in similar energy range. We present results of the comparison of observations from both instruments and show the preliminary results of physical analysis of spectra for selected flares.

  19. Observation of SO2 degassing at Stromboli volcano using a hyperspectral thermal infrared imager

    Science.gov (United States)

    Smekens, Jean-François; Gouhier, Mathieu

    2018-05-01

    Thermal infrared (TIR) imaging is a common tool for the monitoring of volcanic activity. Broadband cameras with increasing sampling frequency give great insight into the physical processes taking place during effusive and explosive event, while Fourier transform infrared (FTIR) methods provide high resolution spectral information used to assess the composition of volcanic gases but are often limited to a single point of interest. Continuing developments in detector technology have given rise to a new class of hyperspectral imagers combining the advantages of both approaches. In this work, we present the results of our observations of volcanic activity at Stromboli volcano with a ground-based imager, the Telops Hyper-Cam LW, when used to detect emissions of sulfur dioxide (SO2) produced at the vent, with data acquired at Stromboli volcano (Italy) in early October of 2015. We have developed an innovative technique based on a curve-fitting algorithm to quickly extract spectral information from high-resolution datasets, allowing fast and reliable identification of SO2. We show in particular that weak SO2 emissions, such as inter-eruptive gas puffing, can be easily detected using this technology, even with poor weather conditions during acquisition (e.g., high relative humidity, presence of fog and/or ash). Then, artificially reducing the spectral resolution of the instrument, we recreated a variety of commonly used multispectral configurations to examine the efficiency of four qualitative SO2 indicators based on simple Brightness Temperature Difference (BTD). Our results show that quickly changing conditions at the vent - including but not limited to the presence of summit fog - render the establishment of meaningful thresholds for BTD indicators difficult. Building on those results, we propose recommendations on the use of multispectral imaging for SO2 monitoring and routine measurements from ground-based instruments.

  20. Airborne observations of far-infrared upwelling radiance in the Arctic

    Directory of Open Access Journals (Sweden)

    Q. Libois

    2016-12-01

    Full Text Available The first airborne measurements of the Far-InfraRed Radiometer (FIRR were performed in April 2015 during the panarctic NETCARE campaign. Vertical profiles of spectral upwelling radiance in the range 8–50 µm were measured in clear and cloudy conditions from the surface up to 6 km. The clear sky profiles highlight the strong dependence of radiative fluxes to the temperature inversion typical of the Arctic. Measurements acquired for total column water vapour from 1.5 to 10.5 mm also underline the sensitivity of the far-infrared greenhouse effect to specific humidity. The cloudy cases show that optically thin ice clouds increase the cooling rate of the atmosphere, making them important pieces of the Arctic energy balance. One such cloud exhibited a very complex spatial structure, characterized by large horizontal heterogeneities at the kilometre scale. This emphasizes the difficulty of obtaining representative cloud observations with airborne measurements but also points out how challenging it is to model polar clouds radiative effects. These radiance measurements were successfully compared to simulations, suggesting that state-of-the-art radiative transfer models are suited to study the cold and dry Arctic atmosphere. Although FIRR in situ performances compare well to its laboratory performances, complementary simulations show that upgrading the FIRR radiometric resolution would greatly increase its sensitivity to atmospheric and cloud properties. Improved instrument temperature stability in flight and expected technological progress should help meet this objective. The campaign overall highlights the potential for airborne far-infrared radiometry and constitutes a relevant reference for future similar studies dedicated to the Arctic and for the development of spaceborne instruments.

  1. Far-infrared observations of Large Magellanic Cloud H II regions

    International Nuclear Information System (INIS)

    Werner, M.W.; Becklin, E.E.; Gatley, I.; Ellis, M.J.; Hyland, A.R.; Robinson, G.; Thomas, J.A.

    1978-01-01

    Far-infrared emission has been measured from four Large Magellanic Cloud H II regions: the 30 Doradus nebula, MC75, MC76 and MC77. The far-infrared radiation is thermal emission from dust heated by starlight. The results show that the LMC H II regions, like H II regions in the Galaxy, have far-infrared luminosities comparable to the total luminosity of their exciting stars. (author)

  2. Far-infrared and CO observations of Cep F: Implications for star formation in Cepheus OB3

    International Nuclear Information System (INIS)

    Sargent, A.I.; van Duinen, R.J.; Nordh, H.L.; Fridlund, C.V.M.; Aalders, J.W.G.; Beintema, D.

    1983-01-01

    Observations at 80-μm and 130-μm have revealed a source of far-infrared emission in the Cep F portion of the Cepheus OB3 molecular cloud. Molecular line measurements of this region, at the CO J = 1-0 line frequency, have led to the discovery of two CO maxima. One of these coincides with the new far-infrared source. The other is at least as intense as Cep B, until now considered to be the hottest part of the cloud. There is some evidence to suggest that a second far-infrared source is associated with this hotspot. If the far-infrared emission results from the presence of embedded protostars, their location, relative to the OB association stars and to the other active region, Cep A, requires a reexamination of how stars form in the Cepheus OB3 association

  3. Impulsive and gradual phases of a solar limb flare as observed from the solar maximum mission satellite

    Energy Technology Data Exchange (ETDEWEB)

    Poland, A.I.; Frost, K.J.; Woodgate, B.E.; Shine, R.A.; Kenny, P.J. (National Aeronautics and Space Administration, Greenbelt, MD (USA). Lab. for Astronomy and Solar Physics); Machado, M.E. (Observatorio Nacional de Fisica Cosmica, San Miguel (Argentina)); Wolfson, C.J.; Bruner, E.C. (Lockheed Palo Alto Research Labs., CA (USA)); Cheng, C.C. (Naval Research Lab., Washington, DC (USA)); Tandberg-Hanssen, E.A. (National Aeronautics and Space Administration, Huntsville, AL (USA). George C. Marshall Space Flight Center)

    1982-06-01

    Simultaneous observations of a solar limb flare in the X-ray and ultraviolet regions of the spectrum are presented. Temporal and spectral X-ray observations were obtained for the 25-300 keV range while temporal, spectral, and spatial X-ray observations were obtained for the 30-0.3 keV range. The ultraviolet observations were images with a 10'' spatial resolution in the lines of O v (Tsub(e) approx. equal to 2.5 x 10/sup 5/ K) and Fe XXI (Tsub(e) approx. equal to 1.1 x 10/sup 7/ K). The hard X-ray and O v data indicate that the impulsive phase began in the photosphere or chromosphere and continued for several minutes as material was ejected into the corona. Impulsive excitation was observed up to 30,000 km above the solar surface at specific points in the flare loop. The Fe XXI observations indicate a preheating before the impulsive phase and showed the formation of hot post-flare loops. This later formation was confirmed by soft X-ray observations. These observations provide limitations for current flare models and will provide the data needed for initial conditions in modeling the concurrent coronal transient.

  4. The impulsive and gradual phases of a solar limb flare as observed from the solar maximum mission satellite

    International Nuclear Information System (INIS)

    Poland, A.I.; Frost, K.J.; Woodgate, B.E.; Shine, R.A.; Kenny, P.J.; Wolfson, C.J.; Bruner, E.C.; Cheng, C.C.; Tandberg-Hanssen, E.A.

    1982-01-01

    Simultaneous observations of a solar limb flare in the X-ray and ultraviolet regions of the spectrum are presented. Temporal and spectral X-ray observations were obtained for the 25-300 keV range while temporal, spectral, and spatial X-ray observations were obtained for the 30-0.3 keV range. The ultraviolet observations were images with a 10'' spatial resolution in the lines of O v (Tsub(e) approx. equal to 2.5 x 10 5 K) and Fe XXI (Tsub(e) approx. equal to 1.1 x 10 7 K). The hard X-ray and O v data indicate that the impulsive phase began in the photosphere or chromosphere and continued for several minutes as material was ejected into the corona. Impulsive excitation was observed up to 30,000 km above the solar surface at specific points in the flare loop. The Fe XXI observations indicate a preheating before the impulsive phase and showed the formation of hot post-flare loops. This later formation was confirmed by soft X-ray observations. These observations provide limitations for current flare models and will provide the data needed for initial conditions in modeling the concurrent coronal transient. (orig.)

  5. Harnessing solar pressure to slew and point large infrared space telescopes

    Science.gov (United States)

    Errico, Simona; Angel, Roger P.; Calvert, Paul D.; Woof, Neville

    2003-03-01

    Large astronomical Gossamer telescopes in space will need to employ large solar shields to safeguard the optics from solar radiation. These types of telescopes demand accurate controls to maintain telescope pointing over long integration periods. We propose an active solar shield system that harnesses radiation pressure to accurately slew and acquire new targets without the need for reaction wheels or thrusters. To provide the required torques, the solar shield is configured as an inverted, 4-sided pyramidal roof. The sloped roof interior surfaces are covered with hinged “tiles” made from piezoelectric film bimorphs with specular metallized surfaces. Nominally, the tiles lie flat against the roof and the sunlight is reflected outward equally from all sloped surfaces. However, when the tiles on one roof pitch are raised, the pressure balance is upset and the sunshade is pushed to one side. By judicious selection of the tiles and control of their lift angle, the solar pressure can be harvested to stabilize the spacecraft orientation or to change its angular momentum. A first order conceptual design performance analysis and the results from the experimental design, fabrication and testing of piezoelectric bimorph hinge elements will be presented. Next phase challenges in engineering design, materials technology, and systems testing will be discussed.

  6. CORONAGRAPHIC OBSERVATIONS OF FOMALHAUT AT SOLAR SYSTEM SCALES

    International Nuclear Information System (INIS)

    Kenworthy, Matthew A.; Meshkat, Tiffany; Quanz, Sascha P.; Meyer, Michael R.; Girard, Julien H.; Kasper, Markus

    2013-01-01

    We report on a search for low mass companions within 10 AU of the star Fomalhaut, using narrowband observations at 4.05 μm obtained with the Apodizing Phase Plate coronagraph on the VLT/NaCo. Our observations place a model-dependent upper mass limit of 12-20 M jup from 4 to 10 AU, covering the semimajor axis search space between interferometric imaging measurements and other direct imaging non-detections. These observations rule out models where the large semimajor axis for the putative candidate companion Fomalhaut b is explained by dynamical scattering from a more massive companion in the inner stellar system, where such giant planets are thought to form.

  7. HAWC+/SOFIA observations of Rho Oph A: far-infrared polarization spectrum

    Science.gov (United States)

    Santos, Fabio; Dowell, Charles D.; Houde, Martin; Looney, Leslie; Lopez-Rodriguez, Enrique; Novak, Giles; Ward-Thompson, Derek; HAWC+ Science Team

    2018-01-01

    In this work, we present preliminary results from the HAWC+ far-infrared polarimeter that operates on the SOFIA airborne observatory. The densest portions of the Rho Ophiuchi molecular complex, known as Rho Oph A, have been mapped using HAWC+ bands C (89 microns) and D (155 microns). Rho Oph A is a well known nearby star forming region. At the target's distance of approximately 130 pc, our observations provide excellent spatial resolution (~5 mpc in band C).The magnetic field map suggests a compressed and distorted field morphology around Oph S1, a massive B3 star that is the main heat source of Rho Oph A. We compute the ratio p(D)/p(C), where p(C) and p(D) are the polarization degree maps at bands C and D, respectively. This ratio estimates the slope of the polarization spectrum in the far-infrared. Although the slope is predicted to be positive by dust grain models, previous observations of other molecular clouds have revealed that negative slopes are common. In Rho Oph A, we find that there is a smooth gradient of p(D)/p(C) across the mapped field. The change in p(D)/p(C) is well correlated with the integrated NH3 (1,1) emission. A positive slope dominates the lower density and well illuminated portions of the cloud, whereas a transition to a negative slope is observed at the denser and less evenly illuminated cloud core.We interpret the positive to negative slope transition as being consistent with the radiative torques (RATs) grain alignment theory. For the sight lines of higher column density, polarized emission from the warmer outer cloud layers is added to emission from the colder inner well-shielded layers lying along the same line-of-sight. Given that the outer layers receive more radiation from Oph S1, their grain alignment efficiency is expected to be higher according to RATs. The combination of warmer, well aligned grains with cooler, poorly aligned grains is what causes the negative slope. This effect is not present in the sight lines of lower column

  8. Faraday rotation fluctutation spectra observed during solar occultation of the Helios spacecraft

    Science.gov (United States)

    Andreev, V.; Efimov, A. I.; Samoznaev, L.; Bird, M. K.

    1995-01-01

    Faraday rotation (FR) measurements using linearly polarized radio signals from the two Helios spacecraft were carried out during the period from 1975 to 1984. This paper presents the results of a spectral analysis of the Helios S-band FR fluctuations observed at heliocentric distances from 2.6 to 15 solar radii during the superior conjunctions 1975-1983. The mean intensity of the FR fluctuations does not exceed the noise level for solar offsets greater than ca. 15 solar radii. The rms FR fluctuation amplitude increases rapidly as the radio ray path approaches the Sun, varying according to a power law (exponent: 2.85 +/- 0.15) at solar distances 4-12 solar radii. At distances inside 4 solar radii the increase is even steeper (exponent: 5.6 +/- 0.2). The equivalent two-dimensional FR fluctuation spectrum is well modeled by a single power-law over the frequency range from 5 to 50 mHz. For heliocentric distances larger than 4 solar radii the spectral index varies between 1.1 and 1.6 with a mean value of 1.4 +/- 0.2, corresponding to a 3-D spectral index p = 2.4. FR fluctuations thus display a somwhat lower spectral index compared with phase and amplitude fluctuations. Surprisingly high values of the spectral index were found for measurements inside 4 solar radii (p = 2.9 +/- 0.2). This may arise from the increasingly dominant effect of the magnetic field on radio wave propagation at small solar offsets. Finally, a quasiperiodic component, believed to be associated with Alfven waves, was discovered in some (but not all!) fluctuation spectra observed simultaneously at two ground stations. Characteristic periods and bulk velocities of this component were 240 +/- 30 sec and 300 +/- 60 km/s, respectively.

  9. ONSETS AND SPECTRA OF IMPULSIVE SOLAR ENERGETIC ELECTRON EVENTS OBSERVED NEAR THE EARTH

    International Nuclear Information System (INIS)

    Kontar, Eduard P.; Reid, Hamish A. S.

    2009-01-01

    Impulsive solar energetic electrons are often observed in the interplanetary space near the Earth and have an attractive diagnostic potential for poorly understood solar flare acceleration processes. We investigate the transport of solar flare energetic electrons in the heliospheric plasma to understand the role of transport to the observed onset and spectral properties of the impulsive solar electron events. The propagation of energetic electrons in solar wind plasma is simulated from the acceleration region at the Sun to the Earth, taking into account self-consistent generation and absorption of electrostatic electron plasma (Langmuir) waves, effects of nonuniform plasma, collisions, and Landau damping. The simulations suggest that the beam-driven plasma turbulence and the effects of solar wind density inhomogeneity play a crucial role and lead to the appearance of (1) a spectral break for a single power-law injected electron spectrum, with the spectrum flatter below the break, (2) apparent early onset of low-energy electron injection, and (3) the apparent late maximum of low-energy electron injection. We show that the observed onsets, spectral flattening at low energies, and formation of a break energy at tens of keV is the direct manifestation of wave-particle interactions in nonuniform plasma of a single accelerated electron population with an initial power-law spectrum.

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

    Science.gov (United States)

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

    2014-08-01

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

  11. Mars Infrared Spectroscopy: From Theory and the Laboratory to Field Observations

    Science.gov (United States)

    Kirkland, L.; Mustard, J.; McAfee, J.; Hapke, B.; Ramsey, M.

    2002-12-01

    Visible-infrared spectroscopy has a long history of providing compositional discoveries in the solar system. A primary goal of the Mars visible-infrared spectral community is to provide information to enhance the exploration of Mars. We are entering an era of Mars exploration with missions every ~2 years. It is critical that each mission provide information to optimize the success of the next mission. That will not occur effectively unless the data can be analyzed on a ~2-year rate. Our current knowledge of spectral properties of materials and effects of the natural environment are not sufficient for the accurate interpretations needed for such time critical objectives. Relevant instruments include the 1996 TES, 2001 THEMIS, 2003 Mars Express OMEGA and PFS, 2003 MER Pancam and Mini-TES, and the 2005 CRISM. Two critical gaps that cannot be filled by individual researchers alone exist in moving toward the goal of rapid and accurate analysis. These are in coordinated "end-to-end" field testing and public spectral libraries. Three related gaps are in data from terrestrial sites to aid interpretations of the orbited spectrometers, lack of high quality development data to support landers, and delays in funding non-flight team members owing to lack of coordination between research and analysis proposal dues dates and mission data releases. A detailed discussion of the each of these areas is in a workshop report through the web site below. The two critical gaps are summarized below. Field Testing. Field/rover, airborne/satellite, and telescopic measurements are sensitive to very different effects, and these differ from those present in the lab. Thus a convincing determination of uncertainties requires demonstration through coordinated "end-to-end" field testing, using: (1) Data sets of appropriate terrestrial analog sites that are measured with both geometric and spectral fidelity as close as possible to flight instruments; (2) Interpretation as applied to data of Mars; (3

  12. Advancing satellite-based solar power forecasting through integration of infrared channels for automatic detection of coastal marine inversion layer

    Energy Technology Data Exchange (ETDEWEB)

    Kostylev, Vladimir; Kostylev, Andrey; Carter, Chris; Mahoney, Chad; Pavlovski, Alexandre; Daye, Tony [Green Power Labs Inc., Dartmouth, NS (Canada); Cormier, Dallas Eugene; Fotland, Lena [San Diego Gas and Electric Co., San Diego, CA (United States)

    2012-07-01

    The marine atmospheric boundary layer is a layer or cool, moist maritime air with the thickness of a few thousand feet immediately below a temperature inversion. In coastal areas as moist air rises from the ocean surface, it becomes trapped and is often compressed into fog above which a layer of stratus clouds often forms. This phenomenon is common for satellite-based solar radiation monitoring and forecasting. Hour ahead satellite-based solar radiation forecasts are commonly using visible spectrum satellite images, from which it is difficult to automatically differentiate low stratus clouds and fog from high altitude clouds. This provides a challenge for cloud motion tyracking and cloud cover forecasting. San Diego Gas and Electric {sup registered} (SDG and E {sup registered}) Marine Layer Project was undertaken to obtain information for integration with PV forecasts, and to develop a detailed understanding of long-term benefits from forecasting Marine Layer (ML) events and their effects on PV production. In order to establish climatological ML patterns, spatial extent and distribution of marine layer, we analyzed visible and IR spectrum satellite images (GOES WEST) archive for the period of eleven years (2000 - 2010). Historical boundaries of marine layers impact were established based on the cross-classification of visible spectrum (VIS) and infrared (IR) images. This approach is successfully used by us and elsewhere for evaluating cloud albedo in common satellite-based techniques for solar radiation monitoring and forecasting. The approach allows differentiation of cloud cover and helps distinguish low laying fog which is the main consequence of marine layer formation. ML occurrence probability and maximum extent inland was established for each hour and day of the analyzed period and seasonal/patterns were described. SDG and E service area is the most affected region by ML events with highest extent and probability of ML occurrence. Influence of ML was the

  13. Coordinated soft X-ray and H-alpha observation of solar flares

    Science.gov (United States)

    Zarro, D. M.; Canfield, R. C.; Metcalf, T. R.; Lemen, J. R.

    1988-01-01

    Soft X-ray, Ca XIX, and H-alpha observations obtained for a set of four solar flares in the impulsive phase are analyzed. A blue asymmetry was observed in the coronal Ca XIX line during the soft-Xray rise phase in all of the events. A red asymmetry was observed simultaneously in chromospheric H-alpha at spatial locations associated with enhanced flare heating. It is shown that the impulsive phase momentum of upflowing soft X-ray plasma equalled that of the downflowing H-alpha plasma to within an order of magnitude. This supports the explosive chromospheric evaporation model of solar flares.

  14. Possible effect of extreme solar energetic particle event of 20 January 2005 on polar stratospheric aerosols: direct observational evidence

    Directory of Open Access Journals (Sweden)

    I. A. Mironova

    2012-01-01

    Full Text Available Energetic cosmic rays are the main source of ionization of the low-middle atmosphere, leading to associated changes in atmospheric properties. Via the hypothetical influence of ionization on aerosol growth and facilitated formation of clouds, this may be an important indirect link relating solar variability to climate. This effect is highly debated, however, since the proposed theoretical mechanisms still remain illusive and qualitative, and observational evidence is inconclusive and controversial. Therefore, important questions regarding the existence and magnitude of the effect, and particularly the fraction of aerosol particles that can form and grow, are still open. Here we present empirical evidence of the possible effect caused by cosmic rays upon polar stratospheric aerosols, based on a case study of an extreme solar energetic particle (SEP event of 20 January 2005. Using aerosol data obtained over polar regions from different satellites with optical instruments that were operating during January 2005, such as the Stratospheric Aerosol and Gas Experiment III (SAGE III, and Optical Spectrograph and Infrared Imaging System (OSIRIS, we found a significant simultaneous change in aerosol properties in both the Southern and Northern Polar regions in temporal association with the SEP event. We speculate that ionization of the atmosphere, which was abnormally high in the lower stratosphere during the extreme SEP event, might have led to formation of new particles and/or growth of preexisting ultrafine particles in the polar stratospheric region. However, a detailed interpretation of the effect is left for subsequent studies. This is the first time high vertical resolution measurements have been used to discuss possible production of stratospheric aerosols under the influence of cosmic ray induced ionization. The observed effect is marginally detectable for the analyzed severe SEP event and can be undetectable for the majority of weak

  15. Possible effect of extreme solar energetic particle event of 20 January 2005 on polar stratospheric aerosols: direct observational evidence

    Science.gov (United States)

    Mironova, I. A.; Usoskin, I. G.; Kovaltsov, G. A.; Petelina, S. V.

    2012-01-01

    Energetic cosmic rays are the main source of ionization of the low-middle atmosphere, leading to associated changes in atmospheric properties. Via the hypothetical influence of ionization on aerosol growth and facilitated formation of clouds, this may be an important indirect link relating solar variability to climate. This effect is highly debated, however, since the proposed theoretical mechanisms still remain illusive and qualitative, and observational evidence is inconclusive and controversial. Therefore, important questions regarding the existence and magnitude of the effect, and particularly the fraction of aerosol particles that can form and grow, are still open. Here we present empirical evidence of the possible effect caused by cosmic rays upon polar stratospheric aerosols, based on a case study of an extreme solar energetic particle (SEP) event of 20 January 2005. Using aerosol data obtained over polar regions from different satellites with optical instruments that were operating during January 2005, such as the Stratospheric Aerosol and Gas Experiment III (SAGE III), and Optical Spectrograph and Infrared Imaging System (OSIRIS), we found a significant simultaneous change in aerosol properties in both the Southern and Northern Polar regions in temporal association with the SEP event. We speculate that ionization of the atmosphere, which was abnormally high in the lower stratosphere during the extreme SEP event, might have led to formation of new particles and/or growth of preexisting ultrafine particles in the polar stratospheric region. However, a detailed interpretation of the effect is left for subsequent studies. This is the first time high vertical resolution measurements have been used to discuss possible production of stratospheric aerosols under the influence of cosmic ray induced ionization. The observed effect is marginally detectable for the analyzed severe SEP event and can be undetectable for the majority of weak-moderate events. The present

  16. A TWO-RIBBON WHITE-LIGHT FLARE ASSOCIATED WITH A FAILED SOLAR ERUPTION OBSERVED BY ONSET, SDO, AND IRIS

    International Nuclear Information System (INIS)

    Cheng, X.; Hao, Q.; Ding, M. D.; Chen, P. F.; Fang, C.; Liu, K.; Liu, Y. D.

    2015-01-01

    Two-ribbon brightenings are one of the most remarkable characteristics of an eruptive solar flare and are often used to predict the occurrence of coronal mass ejections (CMEs). Nevertheless, it was recently called into question whether all two-ribbon flares are eruptive. In this paper, we investigate a two-ribbon-like white-light (WL) flare that is associated with a failed magnetic flux rope (MFR) eruption on 2015 January 13, which has no accompanying CME in the WL coronagraph. Observations by the Optical and Near-infrared Solar Eruption Tracer and the Solar Dynamics Observatory reveal that with the increase of the flare emission and the acceleration of the unsuccessfully erupting MFR, two isolated kernels appear at the WL 3600 Å passband and quickly develop into two elongated ribbon-like structures. The evolution of the WL continuum enhancement is completely coincident in time with the variation of Fermi hard X-ray 26–50 keV flux. An increase of continuum emission is also clearly visible at the whole FUV and NUV passbands observed by the Interface Region Imaging Spectrograph. Moreover, in one WL kernel, the Si iv, C ii, and Mg ii h/k lines display significant enhancement and non-thermal broadening. However, their Doppler velocity pattern is location-dependent. At the strongly bright pixels, these lines exhibit a blueshift, while at moderately bright ones, the lines are generally redshifted. These results show that the failed MFR eruption is also able to produce a two-ribbon flare and high-energy electrons that heat the lower atmosphere, causing the enhancement of the WL and FUV/NUV continuum emissions and chromospheric evaporation

  17. Observation and Interpretation of Energetic Neutral Hydrogen Atoms from the December 5, 2006 Solar Event

    Science.gov (United States)

    Mewaldt, R. A.; Leske, R. A.; Stone, E. C.; Barghouty, A. F.; Shih, A. Y.; von Rosenvinge, T. T.; Labrador, A. W.; Cohen, C. M. S.; Cummings, A. C.; Cummings, A. C.

    2009-01-01

    We report the first observations of energetic neutral atoms (ENAs) from a solar flare/coronal mass ejection event. The observations were made during the December 5, 2006 X9 solar flare, located at E79, by the Low Energy Telescopes (LETs) on the STEREO A and B spacecraft. Within 1-2 hours of the flare onset, both LETs observed a sudden burst of 1.6 to 15 MeV protons arriving hours before the onset of the main solar energetic particle (SEP) event at Earth. More than 70% of these particles arrived from a longitude within +-10 degrees of the Sun. The derived emission profile at the Sun lasted for more than an hour and had a profile remarkably similar to the GOES soft X-ray profile. The observed arrival directions and energy spectrum argue strongly that the particle events atoms that were stripped of their electrons upon entering the LET sensor. To our knowledge, this is the first reported observation of ENA emission from a solar flare/coronal mass ejection. We discuss possible origins for the production of ENAs in solar events, including charge-transfer reactions involving both flare and shock-accelerated protons. Assuming isotropic emission, we find that 2 x 10E28 ENAs escaped from the Sun in the upper hemisphere. Based on the 2.2 MeV gamma-ray emission observed by RHESSI in this event, and using measured and theoretical cross sections, we estimate that 3 x 10E31 ENAs with 1.8 - 5 MeV could be produced by protons accelerated in the flare. CME-driven shock acceleration is also a possible ENA source, but unfortunately there were no CME observations available from this event. Taking into account ENA losses, we conclude that the observed ENAs were most likely produced in the high corona at heliocentric distances 1.6 solar radii.

  18. Analysis of Enhanced Velocity Signals Observed during Solar Flares ...

    Indian Academy of Sciences (India)

    2003-10-28

    Oct 28, 2003 ... close to the vicinity of the hard X-ray source regions as observed with. RHESSI. The power maps of the active region show enhancement in the frequency regime 5–6.5mHz, while there is feeble or no enhancement of these signals in 2–4 mHz frequency band. High energy particles with sufficient momentum ...

  19. ISO far-infrared observations of rich galaxy clusters I. Abell 2670

    DEFF Research Database (Denmark)

    Hansen, Lene; Jorgensen, H.E.; Nørgaard-Nielsen, Hans Ulrik

    1999-01-01

    As part of an investigation of far-infrared emission from rich galaxy clusters the central part of Abell 2670 has been mapped with ISO at 60 mu m, 100 mu m, 135 mu m, and 200 mu m using the PHT-C camera. Point sources detected in the field have infrared fluxes comparable to normal spirals...

  20. Sodium Pick-Up Ion Observations in the Solar Wind Upstream of Mercury

    Science.gov (United States)

    Jasinski, J. M.; Raines, J. M.; Slavin, J. A.; Regoli, L. R.; Murphy, N.

    2018-05-01

    We present the first observations of sodium pick-up ions upstream of Mercury’s magnetosphere. From these observations we infer properties of Mercury’s sodium exosphere and implications for the solar wind interaction with Mercury’s magnetosphere.

  1. Design of a Solar Greenhouse with Energy Delivery by the Conversion of Near Infrared Radiation - Part 1 Optics and PV-cells

    NARCIS (Netherlands)

    Gert-Jan Swinkels; Piet Sonneveld; G.P.A. Bot

    2009-01-01

    In this paper the design and development of a new type of greenhouse with an integrated filter for reflecting near infrared radiation (NIR) and a solar energy delivery system is described. Especially the optical parts as the spectral selective film, the properties of the circular reflector and the

  2. Design of a Solar Greenhouse with energy Delivery by the Conversion of Near Infrared Radiation. Part 1. Optics and PV-Cells

    NARCIS (Netherlands)

    Sonneveld, P.J.; Swinkels, G.L.A.M.; Bot, G.P.A.

    2009-01-01

    In this paper the design and development of a new type of greenhouse with an integrated filter for reflecting near infrared radiation (NIR) and a solar energy delivery system is described. Especially the optical parts as the spectral selective film, the properties of the circular reflector and the

  3. Observations of apparent superslow wave propagation in solar prominences

    Science.gov (United States)

    Raes, J. O.; Van Doorsselaere, T.; Baes, M.; Wright, A. N.

    2017-06-01

    Context. Phase mixing of standing continuum Alfvén waves and/or continuum slow waves in atmospheric magnetic structures such as coronal arcades can create the apparent effect of a wave propagating across the magnetic field. Aims: We observe a prominence with SDO/AIA on 2015 March 15 and find the presence of oscillatory motion. We aim to demonstrate that interpreting this motion as a magneto hydrodynamic (MHD) wave is faulty. We also connect the decrease of the apparent velocity over time with the phase mixing process, which depends on the curvature of the magnetic field lines. Methods: By measuring the displacement of the prominence at different heights to calculate the apparent velocity, we show that the propagation slows down over time, in accordance with the theoretical work of Kaneko et al. We also show that this propagation speed drops below what is to be expected for even slow MHD waves for those circumstances. We use a modified Kippenhahn-Schlüter prominence model to calculate the curvature of the magnetic field and fit our observations accordingly. Results: Measuring three of the apparent waves, we get apparent velocities of 14, 8, and 4 km s-1. Fitting a simple model for the magnetic field configuration, we obtain that the filament is located 103 Mm below the magnetic centre. We also obtain that the scale of the magnetic field strength in the vertical direction plays no role in the concept of apparent superslow waves and that the moment of excitation of the waves happened roughly one oscillation period before the end of the eruption that excited the oscillation. Conclusions: Some of the observed phase velocities are lower than expected for slow modes for the circumstances, showing that they rather fit with the concept of apparent superslow propagation. A fit with our magnetic field model allows for inferring the magnetic geometry of the prominence. The movie attached to Fig. 1 is available at http://www.aanda.org

  4. New Observations of Soft X-ray (0.5-5 keV) Solar Spectra

    Science.gov (United States)

    Caspi, A.; Woods, T. N.; Mason, J. P.; Jones, A. R.; Warren, H. P.

    2013-12-01

    The solar corona is the brightest source of X-rays in the solar system, and the X-ray emission is highly variable on many time scales. However, the actual solar soft X-ray (SXR) (0.5-5 keV) spectrum is not well known, particularly during solar quiet periods, as, with few exceptions, this energy range has not been systematically studied in many years. Previous observations include high-resolution but very narrow-band spectra from crystal spectrometers (e.g., Yohkoh/BCS), or integrated broadband irradiances from photometers (e.g., GOES/XRS, TIMED/XPS, etc.) that lack detailed spectral information. In recent years, broadband measurements with moderate energy resolution (~0.5-0.7 keV FWHM) were made by SphinX on CORONAS-Photon and SAX on MESSENGER, although they did not extend to energies below ~1 keV. We present observations of solar SXR emission obtained using new instrumentation flown on recent SDO/EVE calibration rocket underflights. The photon-counting spectrometer, a commercial Amptek X123 with a silicon drift detector and an 8 μm Be window, measures the solar disk-integrated SXR emission from ~0.5 to >10 keV with ~0.15 keV FWHM resolution and 1 s cadence. A novel imager, a pinhole X-ray camera using a cooled frame-transfer CCD (15 μm pixel pitch), Ti/Al/C filter, and 5000 line/mm Au transmission grating, images the full Sun in multiple spectral orders from ~0.1 to ~5 nm with ~10 arcsec/pixel and ~0.01 nm/pixel spatial and spectral detector scales, respectively, and 10 s cadence. These instruments are prototypes for future CubeSat missions currently being developed. We present new results of solar observations on 04 October 2013 (NASA sounding rocket 36.290). We compare with previous results from 23 June 2012 (NASA sounding rocket 36.286), during which solar activity was low and no signal was observed above ~4 keV. We compare our spectral and imaging measurements with spectra and broadband irradiances from other instruments, including SDO/EVE, GOES/XRS, TIMED

  5. STEREO Observations of Energetic Neutral Hydrogen Atoms during the 5 December 2006 Solar Flare

    Science.gov (United States)

    Mewaldt, R. A.; Leske, R. A.; Stone, E. C.; Barghouty, A. F.; Labrador, A. W.; Cohen, C. M. S.; Cummings, A. C.; Davis, A. J.; vonRosenvinge, T. T.; Wiedenbeck, M. E.

    2009-01-01

    We report the discovery of energetic neutral hydrogen atoms emitted during the X9 solar event of December 5, 2006. Beginning 1 hour following the onset of this E79 flare, the Low Energy Telescopes (LETs) on both the STEREO A and B spacecraft observed a sudden burst of 1.6 to 15 MeV protons beginning hours before the onset of the main solar energetic particle (SEP) event at Earth. More than 70% of these particles arrived from a longitude within 10 of the Sun, consistent with the measurement resolution. The derived emission profile at the Sun had onset and peak times remarkably similar to the GOES soft X-ray profile and continued for more than an hour. The observed arrival directions and energy spectrum argue strongly that the particle events less than 5 MeV were due to energetic neutral hydrogen atoms (ENAs). To our knowledge, this is the first reported observation of ENA emission from a solar flare/coronal mass ejection. Possible origins for the production of ENAs in a large solar event are considered. We conclude that the observed ENAs were most likely produced in the high corona and that charge-transfer reactions between accelerated protons and partially-stripped coronal ions are an important source of ENAs in solar events.

  6. Observation and Interpretation of Energetic Neutral Hydrogen Atoms from the December 5, 2006 Solar Flare

    Science.gov (United States)

    Barghouty, A. F.; Mewaldt, R. A.; Leske, R. A.; Shih, A. Y.; Stone, E. C.; Cohen, C. M. S.; Cummings, A. C.; Labrador, A. W.; vonRosenvinge, T. T.; Wiedenbeck, M. E.

    2009-01-01

    We discuss observations of energetic neutral hydrogen atoms (ENAs) from a solar flare/coronal mass ejection event reported by Mewaldt et al. (2009). The observations were made during the 5 December 2006 X9 solar flare, located at E79, by the Low Energy Telescopes (LETs) on STEREO A and B. Prior to the arrival of the main solar energetic particle (SEP) event at Earth, both LETs observed a sudden burst of 1.6 to 15 MeV particles arriving from the Sun. The derived solar emission profile, arrival directions, and energy spectrum all show that the atoms produced by either flare or shock-accelerated protons. RHESSI measurements of the 2.2-MeV gamma-ray line provide an estimate of the number of interacting flare-accelerated protons in this event, which leads to an improved estimate of ENA production by flare-accelerated protons. CME-driven shock acceleration is also considered. Taking into account ENA losses, we conclude that the observed ENAs must have been produced in the high corona at heliocentric distances .2 solar radii.

  7. Data analysis for solar neutrinos observed by water Cherenkov detectors{sup *}

    Energy Technology Data Exchange (ETDEWEB)

    Koshio, Yusuke [Okayama University, Okayama (Japan)

    2016-04-15

    A method of analyzing solar neutrino measurements using water-based Cherenkov detectors is presented. The basic detection principle is that the Cherenkov photons produced by charged particles via neutrino interaction are observed by photomultiplier tubes. A large amount of light or heavy water is used as a medium. The first detector to successfully measure solar neutrinos was Kamiokande in the 1980's. The next-generation detectors, i.e., Super-Kamiokande and the Sudbury Neutrino Observatory (SNO), commenced operation from the mid-1990's. These detectors have been playing the critical role of solving the solar neutrino problem and determining the neutrino oscillation parameters over the last decades. The future prospects of solar neutrino analysis using this technique are also described. (orig.)

  8. Vortex, ULF wave and Aurora Observation after Solar Wind Dynamic Pressure Change

    Science.gov (United States)

    Shi, Q.

    2017-12-01

    Here we will summarize our recent study and show some new results on the Magnetosphere and Ionosphere Response to Dynamic Pressure Change/disturbances in the Solar Wind and foreshock regions. We study the step function type solar wind dynamic pressure change (increase/decrease) interaction with the magnetosphere using THEMIS satellites at both dayside and nightside in different geocentric distances. Vortices generated by the dynamic pressure change passing along the magnetopause are found and compared with model predictions. ULF waves and vortices are excited in the dayside and nightside plasma sheet when dynamic pressure change hit the magnetotail. The related ionospheric responses, such as aurora and TCVs, are also investigated. We compare Global MHD simulations with the observations. We will also show some new results that dayside magnetospheric FLRs might be caused by foreshock structures.Shi, Q. Q. et al. (2013), THEMIS observations of ULF wave excitation in the nightside plasma sheet during sudden impulse events, J. Geophys. Res. Space Physics, 118, doi:10.1029/2012JA017984. Shi, Q. Q. et al. (2014), Solar wind pressure pulse-driven magnetospheric vortices and their global consequences, J. Geophys. Res. Space Physics, 119, doi:10.1002/2013JA019551. Tian, A.M. et al.(2016), Dayside magnetospheric and ionospheric responses to solar wind pressure increase: Multispacecraft and ground observations, J. Geophys. Res., 121, doi:10.1002/2016JA022459. Shen, X.C. et al.(2015), Magnetospheric ULF waves with increasing amplitude related to solar wind dynamic pressure changes: THEMIS observations, J. Geophys. Res., 120, doi:10.1002/2014JA020913Zhao, H. Y. et al. (2016), Magnetospheric vortices and their global effect after a solar wind dynamic pressure decrease, J. Geophys. Res. Space Physics, 121, doi:10.1002/2015JA021646. Shen, X. C., et al. (2017), Dayside magnetospheric ULF wave frequency modulated by a solar wind dynamic pressure negative impulse, J. Geophys. Res

  9. Propagation of energetic electrons in the solar corona observed with LOFAR

    Science.gov (United States)

    Breitling, F.

    2017-06-01

    This work reports about new high-resolution imaging and spectroscopic observations of solar type III radio bursts at low radio frequencies in the range from 30 to 80 MHz. Solar type III radio bursts are understood as result of the beam-plasma interaction of electron beams in the corona. The Sun provides a unique opportunity to study these plasma processes of an active star. Its activity appears in eruptive events like flares, coronal mass ejections and radio bursts which are all accompanied by enhanced radio emission. Therefore solar radio emission carries important information about plasma processes associated with the Sun's activity. Moreover, the Sun's atmosphere is a unique plasma laboratory with plasma processes under conditions not found in terrestrial laboratories. Because of the Sun's proximity to Earth, it can be studied in greater detail than any other star but new knowledge about the Sun can be transfer to them. This "solar stellar connection" is important for the understanding of processes on other stars. The novel radio interferometer LOFAR provides imaging and spectroscopic capabilities to study these processes at low frequencies. Here it was used for solar observations. LOFAR, the characteristics of its solar data and the processing and analysis of the latter with the Solar Imaging Pipeline and Solar Data Center are described. The Solar Imaging Pipeline is the central software that allows using LOFAR for solar observations. So its development was necessary for the analysis of solar LOFAR data and realized here. Moreover a new density model with heat conduction and Alfvén waves was developed that provides the distance of radio bursts to the Sun from dynamic radio spectra. Its application to the dynamic spectrum of a type III burst observed on March 16, 2016 by LOFAR shows a nonuniform radial propagation velocity of the radio emission. The analysis of an imaging observation of type III bursts on June 23, 2012 resolves a burst as bright, compact region

  10. Evolution of Titan's Lakes and Seas: Insights from Recent Infrared Observations

    Science.gov (United States)

    Sotin, C.; Seignovert, B.; Lawrence, K.; Barnes, J. W.; Brown, R. H.; Hayes, A.; Le Mouelic, S.; Baines, K. H.; Buratti, B. J.; Clark, R. N.; Nicholson, P. D.

    2013-12-01

    Titan's North Pole has been illuminated since the spring equinox in August 2009, allowing optical remote sensing instruments to acquire images of the lakes and seas that were discovered by the radar instrument earlier in the Cassini mission [1]. The illumination geometry continually improves with the incidence angle decreasing to its minimum at the summer solstice in 2017. Combined with highly inclined flybys that allow for small values of the emission angle, the 2013 observations are much less affected by the haze scattering because the optical path through the atmosphere is much shorter. The Visual and Infrared Mapping Spectrometer (VIMS) can observe Titan's surface in seven infrared atmospheric windows between 0.96- and 5-μm. This study describes observations acquired during the recent T93 flyby on July 26, 2013. The footprint ranges from 10 km/pixel to 3 km/pixel. Maps of the three large seas (Ligeia Mare, Punga Mare, and Kraken Mare) at seven different wavelengths are being constructed and a mosaic of the lake area is being assembled. Ligeia Mare was previously imaged by the VIMS in June 2010 [2]. A preliminary analysis of the 2-μm map suggests that the shoreline has not evolved since 2010. The shape of the 2- μm atmospheric window will be compared between the two images and between the mare and the shore to investigate whether liquid ethane is present as is the case on Ontario lacus [3]. The lake area located between 0 and 90W was imaged with a resolution that allows comparison with the radar images. A preliminary comparison between the two data sets shows a very strong correlation. One part of Punga mare and a lake known as Kivu lacus were acquired on the same image. The northeastern part of Punga Mare seems entailed by a river network. No connections between Punga mare and Kivu lacus are observed on the VIMS image. Kivu lacus seems to lie in the center of a circular depression whose limit is bright at 2-μm. Equipotential maps are built from the

  11. Linking optical and infrared observations with gravitational wave sources through transient variability

    International Nuclear Information System (INIS)

    Stubbs, C W

    2008-01-01

    Optical and infrared observations have thus far detected more celestial cataclysms than have been seen in gravity waves (GW). This argues that we should search for gravity wave signatures that correspond to transient variables seen at optical wavelengths, at precisely known positions. There is an unknown time delay between the optical and gravitational transient, but knowing the source location precisely specifies the corresponding time delays across the gravitational antenna network as a function of the GW-to-optical arrival time difference. Optical searches should detect virtually all supernovae that are plausible gravitational radiation sources. The transient optical signature expected from merging compact objects is not as well understood, but there are good reasons to expect detectable transient optical/IR emission from most of these sources as well. The next generation of deep wide-field surveys (for example PanSTARRS and LSST) will be sensitive to subtle optical variability, but we need to fill the 'blind spots' that exist in the galactic plane, and for optically bright transient sources. In particular, a galactic plane variability survey at λ∼ 2 μm seems worthwhile. Science would benefit from closer coordination between the various optical survey projects and the gravity wave community

  12. High resolution far-infrared observations of the evolved H II region M16

    International Nuclear Information System (INIS)

    McBreen, B.; Fazio, G.G.; Jaffe, D.T.

    1982-01-01

    M16 is an evolved, extremely density bounded H II region, which now consists only of a series of ionization fronts at molecular cloud boundaries. The source of ionization is the OB star cluster (NGC 6611) which is about 5 x 10 6 years old. We used the CFA/UA 102 cm balloon-borne telescope to map this region and detected three far-infrared (far-IR) sources embedded in an extended ridge of emission. Source I is an unresolved far-IR source embedded in a molecular cloud near a sharp ionization front. An H 2 O maser is associated with this source, but no radio continuum emission has been observed. The other two far-IR sources (II and III) are associated with ionized gas-molecular cloud interfaces, with the far-IR radiation arising from dust at the boundary heated by the OB cluster. Source II is located at the southern prominent neutral intrusion with its associated bright rims and dark ''elephant trunk'' globules that delineate the current progress of the ionization front into the neutral material, and Source III arises at the interface of the northern molecular cloud fragment

  13. Bio-inspired Plasmonic Nanoarchitectured Hybrid System Towards Enhanced Far Red-to-Near Infrared Solar Photocatalysis

    Science.gov (United States)

    Yan, Runyu; Chen, Min; Zhou, Han; Liu, Tian; Tang, Xingwei; Zhang, Ke; Zhu, Hanxing; Ye, Jinhua; Zhang, Di; Fan, Tongxiang

    2016-01-01

    Solar conversion to fuels or to electricity in semiconductors using far red-to-near infrared (NIR) light, which accounts for about 40% of solar energy, is highly significant. One main challenge is the development of novel strategies for activity promotion and new basic mechanisms for NIR response. Mother Nature has evolved to smartly capture far red-to-NIR light via their intelligent systems due to unique micro/nanoarchitectures, thus motivating us for biomimetic design. Here we report the first demonstration of a new strategy, based on adopting nature’s far red-to-NIR responsive architectures for an efficient bio-inspired photocatalytic system. The system is constructed by controlled assembly of light-harvesting plasmonic nanoantennas onto a typical photocatalytic unit with butterfly wings’ 3D micro/nanoarchitectures. Experiments and finite-difference time-domain (FDTD) simulations demonstrate the structural effects on obvious far red-to-NIR photocatalysis enhancement, which originates from (1) Enhancing far red-to-NIR (700~1200 nm) harvesting, up to 25%. (2) Enhancing electric-field amplitude of localized surface plasmon (LSPs) to more than 3.5 times than that of the non-structured one, which promotes the rate of electron-hole pair formation, thus substantially reinforcing photocatalysis. This proof-of-concept study provides a new methodology for NIR photocatalysis and would potentially guide future conceptually new NIR responsive system designs.

  14. Bio-inspired Plasmonic Nanoarchitectured Hybrid System Towards Enhanced Far Red-to-Near Infrared Solar Photocatalysis.

    Science.gov (United States)

    Yan, Runyu; Chen, Min; Zhou, Han; Liu, Tian; Tang, Xingwei; Zhang, Ke; Zhu, Hanxing; Ye, Jinhua; Zhang, Di; Fan, Tongxiang

    2016-01-28

    Solar conversion to fuels or to electricity in semiconductors using far red-to-near infrared (NIR) light, which accounts for about 40% of solar energy, is highly significant. One main challenge is the development of novel strategies for activity promotion and new basic mechanisms for NIR response. Mother Nature has evolved to smartly capture far red-to-NIR light via their intelligent systems due to unique micro/nanoarchitectures, thus motivating us for biomimetic design. Here we report the first demonstration of a new strategy, based on adopting nature's far red-to-NIR responsive architectures for an efficient bio-inspired photocatalytic system. The system is constructed by controlled assembly of light-harvesting plasmonic nanoantennas onto a typical photocatalytic unit with butterfly wings' 3D micro/nanoarchitectures. Experiments and finite-difference time-domain (FDTD) simulations demonstrate the structural effects on obvious far red-to-NIR photocatalysis enhancement, which originates from (1) Enhancing far red-to-NIR (700~1200 nm) harvesting, up to 25%. (2) Enhancing electric-field amplitude of localized surface plasmon (LSPs) to more than 3.5 times than that of the non-structured one, which promotes the rate of electron-hole pair formation, thus substantially reinforcing photocatalysis. This proof-of-concept study provides a new methodology for NIR photocatalysis and would potentially guide future conceptually new NIR responsive system designs.

  15. BRIGHTNESS AND FLUCTUATION OF THE MID-INFRARED SKY FROM AKARI OBSERVATIONS TOWARD THE NORTH ECLIPTIC POLE

    International Nuclear Information System (INIS)

    Pyo, Jeonghyun; Jeong, Woong-Seob; Matsumoto, Toshio; Matsuura, Shuji

    2012-01-01

    We present the smoothness of the mid-infrared sky from observations by the Japanese infrared astronomical satellite AKARI. AKARI monitored the north ecliptic pole (NEP) during its cold phase with nine wave bands covering from 2.4 to 24 μm, out of which six mid-infrared bands were used in this study. We applied power-spectrum analysis to the images in order to search for the fluctuation of the sky brightness. Observed fluctuation is explained by fluctuation of photon noise, shot noise of faint sources, and Galactic cirrus. The fluctuations at a few arcminutes scales at short mid-infrared wavelengths (7, 9, and 11 μm) are largely caused by the diffuse Galactic light of the interstellar dust cirrus. At long mid-infrared wavelengths (15, 18, and 24 μm), photon noise is the dominant source of fluctuation over the scale from arcseconds to a few arcminutes. The residual fluctuation amplitude at 200'' after removing these contributions is at most 1.04 ± 0.23 nW m –2 sr –1 or 0.05% of the brightness at 24 μm and at least 0.47 ± 0.14 nW m –2 sr –1 or 0.02% at 18 μm. We conclude that the upper limit of the fluctuation in the zodiacal light toward the NEP is 0.03% of the sky brightness, taking 2σ error into account.

  16. Observations of Young Stellar Objects with Infrared Interferometry: Recent Results from PTI, KI and IOTA

    Science.gov (United States)

    Akeson, Rachel

    Young stellar objects have been one of the favorite targets of infrared interferometers for many years. In this contribution I will briefly review some of the first results and their contributions to the field and then describe some of the recent results from the Keck Interferometer (KI), the Palomar Testbed Interferometer (PTI) and the Infrared-Optical Telescope Array (IOTA). This conference also saw many exciting new results from the VLTI at both near and mid-infrared wavelengths that are covered by other contributions.

  17. Near infrared observations of the visual reflection nebulae NGC 7023, NGC 2023, and NGC 2068

    International Nuclear Information System (INIS)

    Sellgren, K.

    1984-01-01

    The emission of the nebulae NGC 7023, 2023, and 2068 at visual wavelengths is due to reflected starlight. Recently the infrared emission of these nebulae has been found to consist not of reflected light, but rather to be due to some other emission process. Spectra of the infrared emission at nebular positions in NGC 7023 and NGC 2023 are shown. The infrared emission consists of a smooth continuum which extends at least from 1.25 to 4.8 μm, and strong emission features at 3.3 and 3.4μm. (author)

  18. X-ray observations of solar flares with the Einstein Observatory

    International Nuclear Information System (INIS)

    Schmitt, J.H.M.M.; Fink, H.; Harnden, F.R. Jr.; Harvard-Smithsonian Center for Astrophysics, Cambridge, MA)

    1987-01-01

    The first Einstein Observatory Imaging Proportional Counter (IPC) observations of solar flares are presented. These flares were detected in scattered X-ray light when the X-ray telescope was pointed at the sunlit earth. The propagation and scattering of solar X-rays in the earth's atmosphere are discussed in order to be able to deduce the solar X-ray flux incident on top of the atmosphere from scattered X-ray intensity measurements. After this correction, the scattered X-ray data are interpreted as full-disk observations of the sun obtained with the same instrumentation used for observations of flares on other stars. Employing the same data analysis and interpretation techniques, extremely good agreement is found between the physical flare parameters deduced from IPC observations and known properties of compact loop flares. This agreement demonstrates that flare observations with the IPC can reveal physical parameters such as temperature and density quite accurately in the solar case and therefore suggests that the interpretations of stellar X-ray flare observations are on a physically sound basis. 26 references

  19. Heliosphere Responds to a Large Solar Wind Intensification: Decisive Observations from IBEX

    Science.gov (United States)

    McComas, D. J.; Dayeh, M. A.; Funsten, H. O.; Heerikhuisen, J.; Janzen, P. H.; Reisenfeld, D. B.; Schwadron, N. A.; Szalay, J. R.; Zirnstein, E. J.

    2018-03-01

    Our heliosphere—the bubble in the local interstellar medium produced by the Sun’s outflowing solar wind—has finally responded to a large increase in solar wind output and pressure in the second half of 2014. NASA’s Interstellar Boundary Explorer (IBEX) mission remotely monitors the outer heliosphere by observing energetic neutral atoms (ENAs) returning from the heliosheath, the region between the termination shock and heliopause. IBEX observed a significant enhancement in higher energy ENAs starting in late 2016. While IBEX observations over the previous decade reflected a general reduction of ENA intensities, indicative of a deflating heliosphere, new observations show that the large (∼50%), persistent increase in the solar wind dynamic pressure has modified the heliosheath, producing enhanced ENA emissions. The combination of these new observations with simulation results indicate that this pressure is re-expanding our heliosphere, with the termination shock and heliopause already driven outward in the locations closest to the Sun. The timing between the IBEX observations, a large transient pressure enhancement seen by Voyager 2, and the simulations indicates that the pressure increase propagated through the heliosheath, reflected off the heliopause, and the enhanced density of the solar wind filled the heliosheath behind it before generating significantly enhanced ENA emissions. The coming years should see significant changes in anomalous cosmic rays, galactic cosmic radiation, and the filtration of interstellar neutral atoms into the inner heliosphere.

  20. Ultra-deep GEMINI Near-infrared Observations of the Bulge Globular Cluster NGC 6624.

    Science.gov (United States)

    Saracino, S.; Dalessandro, E.; Ferraro, F. R.; Geisler, D.; Mauro, F.; Lanzoni, B.; Origlia, L.; Miocchi, P.; Cohen, R. E.; Villanova, S.; Moni Bidin, C.

    2016-11-01

    We used ultra-deep J and K s images secured with the near-infrared (NIR) GSAOI camera assisted by the multi-conjugate adaptive optics system GeMS at the GEMINI South Telescope in Chile, to obtain a (K s , J - K s ) color-magnitude diagram (CMD) for the bulge globular cluster NGC 6624. We obtained the deepest and most accurate NIR CMD from the ground for this cluster, by reaching K s ˜ 21.5, approximately 8 mag below the horizontal branch level. The entire extension of the Main Sequence (MS) is nicely sampled and at K s ˜ 20 we detected the so-called MS “knee” in a purely NIR CMD. By taking advantage of the exquisite quality of the data, we estimated the absolute age of NGC 6624 (t age = 12.0 ± 0.5 Gyr), which turns out to be in good agreement with previous studies in the literature. We also analyzed the luminosity and mass functions of MS stars down to M ˜ 0.45 M⊙, finding evidence of a significant increase of low-mass stars at increasing distances from the cluster center. This is a clear signature of mass segregation, confirming that NGC 6624 is in an advanced stage of dynamical evolution. Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Ministério da Ciência, Tecnologia e Inovação (Brazil) and Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina). Based on observations gathered with ESO-VISTA telescope (program ID 179.B-2002).

  1. Attenuated total reflectance Fourier-transform infrared spectroscopic investigation of silicon heterojunction solar cells

    Czech Academy of Sciences Publication Activity Database

    Holovský, Jakub; De Wolf, S.; Jiříček, Petr; Ballif, C.

    2015-01-01

    Roč. 86, č. 7 (2015), , "073108-1"-"073108-6" ISSN 0034-6748 R&D Projects: GA ČR(CZ) GA14-05053S; GA MŠk 7E12029; GA MŠk(CZ) LM2011026 EU Projects: European Commission(XE) 283501 - Fast Track Institutional support: RVO:68378271 Keywords : FTIR * ATR * solar cells Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.336, year: 2015

  2. Provisional maps of thermal areas in Yellowstone National Park, based on satellite thermal infrared imaging and field observations

    Science.gov (United States)

    Vaughan, R. Greg; Heasler, Henry; Jaworowski, Cheryl; Lowenstern, Jacob B.; Keszthelyi, Laszlo P.

    2014-01-01

    Maps that define the current distribution of geothermally heated ground are useful toward setting a baseline for thermal activity to better detect and understand future anomalous hydrothermal and (or) volcanic activity. Monitoring changes in the dynamic thermal areas also supports decisions regarding the development of Yellowstone National Park infrastructure, preservation and protection of park resources, and ensuring visitor safety. Because of the challenges associated with field-based monitoring of a large, complex geothermal system that is spread out over a large and remote area, satellite-based thermal infrared images from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) were used to map the location and spatial extent of active thermal areas, to generate thermal anomaly maps, and to quantify the radiative component of the total geothermal heat flux. ASTER thermal infrared data acquired during winter nights were used to minimize the contribution of solar heating of the surface. The ASTER thermal infrared mapping results were compared to maps of thermal areas based on field investigations and high-resolution aerial photos. Field validation of the ASTER thermal mapping is an ongoing task. The purpose of this report is to make available ASTER-based maps of Yellowstone’s thermal areas. We include an appendix containing the names and characteristics of Yellowstone’s thermal areas, georeferenced TIFF files containing ASTER thermal imagery, and several spatial data sets in Esri shapefile format.

  3. Relationship between ice water path and downward longwave radiation for clouds optically thin in the infrared: Observations and model calculations

    Science.gov (United States)

    Uttal, Taneil; Matrosov, Sergey Y.; Snider, Jack B.; Kropfli, Robert A.

    1994-01-01

    A vertically pointing 3.2-cm radar is used to observe altostratus and cirrus clouds as they pass overhead. Radar reflectivities are used in combination with an empirical Z(sub i)-IWC (ice water content) relationship developed by Sassen (1987) to parameterize IWC, which is then integrated to obtain estimates of ice water path (IWP). The observed dataset is segregated into all-ice and mixed-phase periods using measurements of integrated liquid water paths (LWP) detected by a collocated, dual-channel microwave radiometer. The IWP values for the all ice periods are compared to measurements of infrared (IR) downward fluxes measured by a collocated narrowband (9.95-11.43 microns) IR radiometer, which results in scattergrams representing the observed dependence of IR fluxes on IWP. A two-stream model is used to calculate the infrared fluxes expected from ice clouds with boundary conditions specified by the actual clouds, and similar curves relating IWP and infrared fluxes are obtained. The model and observational results suggest that IWP is one of the primary controls on infrared thermal fluxes for ice clouds.

  4. A Near-Infrared Photon Counting Camera for High Sensitivity Astronomical Observation, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovation is a Near Infrared Photon-Counting Sensor (NIRPCS), an imaging device with sufficient sensitivity to capture the spectral signatures, in the...

  5. A Near-Infrared Photon Counting Camera for High Sensitivity Astronomical Observation, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovation is a Near Infrared Photon-Counting Sensor (NIRPCS), an imaging device with sufficient sensitivity to capture the spectral signatures, in the...

  6. The 2016 Transit of Mercury Observed from Major Solar Telescopes and Satellites

    Science.gov (United States)

    Pasachoff, Jay M.; Schneider, Glenn; Gary, Dale; Chen, Bin; Sterling, Alphonse C.; Reardon, Kevin P.; Dantowitz, Ronald; Kopp, Greg A.

    2016-10-01

    We report observations from the ground and space of the 9 May 2016 transit of Mercury. We build on our explanation of the black-drop effect in transits of Venus based on spacecraft observations of the 1999 transit of Mercury (Schneider, Pasachoff, and Golub, Icarus 168, 249, 2004). In 2016, we used the 1.6-m New Solar Telescope at the Big Bear Solar Observatory with active optics to observe Mercury's transit at high spatial resolution. We again saw a small black-drop effect as 3rd contact neared, confirming the data that led to our earlier explanation as a confluence of the point-spread function and the extreme solar limb darkening (Pasachoff, Schneider, and Golub, in IAU Colloq. 196, 2004). We again used IBIS on the Dunn Solar Telescope of the Sacramento Peak Observatory, as A. Potter continued his observations, previously made at the 2006 transit of Mercury, at both telescopes of the sodium exosphere of Mercury (Potter, Killen, Reardon, and Bida, Icarus 226, 172, 2013). We imaged the transit with IBIS as well as with two RED Epic IMAX-quality cameras alongside it, one with a narrow passband. We show animations of our high-resolution ground-based observations along with observations from XRT on JAXA's Hinode and from NASA's Solar Dynamics Observatory. Further, we report on the limit of the transit change in the Total Solar Irradiance, continuing our interest from the transit of Venus TSI (Schneider, Pasachoff, and Willson, ApJ 641, 565, 2006; Pasachoff, Schneider, and Willson, AAS 2005), using NASA's SORCE/TIM and the Air Force's TCTE/TIM. See http://transitofvenus.info and http://nicmosis.as.arizona.edu.Acknowledgments: We were glad for the collaboration at Big Bear of Claude Plymate and his colleagues of the staff of the Big Bear Solar Observatory. We also appreciate the collaboration on the transit studies of Robert Lucas (Sydney, Australia) and Evan Zucker (San Diego, California). JMP appreciates the sabbatical hospitality of the Division of Geosciences and

  7. Spectrographic observations of solar microwave bursts in the 5.3-7.4 GHz range

    International Nuclear Information System (INIS)

    Kaverin, N.S.; Korshunov, A.I.; Shushunov, V.V.; Aurass, H.; Detlefs, H.; Hartmann, H.; Krueger, A.; Kurths, J.

    1983-01-01

    The first results of the Gorky-type microwave spectrograph of Tremsdorf solar radioastronomy observatory are given, observed after the reconstruction of the instrument to get a higher time resolution for the spectral observations. Two 5.3-7.4 GHz microwave burst spectral diagrams are shown having 20 s time resolution. Broad-bond spectral structures of the microwave burst development have been observed. Explanation of a 'pseudo-drift' phenomenon due to individual peaks is given. (D.Gy.)

  8. Wide-field Infrared Survey Explorer Observations of the Evolution of Massive Star-forming Regions

    OpenAIRE

    Koenig, X. P.; Leisawitz, D. T.; Benford, D. J.; Rebull, L. M.; Padgett, D. L.; Assef, R. J.

    2012-01-01

    We present the results of a mid-infrared survey of 11 outer Galaxy massive star-forming regions and 3 open clusters with data from the Wide-field Infrared Survey Explorer (WISE). Using a newly developed photometric scheme to identify young stellar objects and exclude extragalactic contamination, we have studied the distribution of young stars within each region. These data tend to support the hypothesis that latter generations may be triggered by the interaction of winds and radiation from th...

  9. Mid-Infrared Observations of the White Dwarf Brown Dwarf Binary GD 1400

    OpenAIRE

    Farihi, J.; Zuckerman, B.; Becklin, E. E.

    2005-01-01

    Fluxes are measured for the DA white dwarf plus brown dwarf pair GD 1400 with the Infrared Array Camera on the {\\em Spitzer Space Telescope}. GD 1400 displays an infrared excess over the entire $3-8\\mu$m region consistent with the presence of a mid- to late-type L dwarf companion. A discussion is given regarding current knowledge of this unique system.

  10. Report on the Dutch expedition to observe the 1973 June 30 solar eclipse. I

    International Nuclear Information System (INIS)

    Houtgast, J.; Namba, O.

    1979-01-01

    In this paper the authors report the Dutch expedition to Atar, Mauritania, to observe the total solar eclipse of June 30, 1973. The purpose of this expedition was to obtain spectra from the transition region photosphere-chromosphere with high spectral and time resolution. The instrumentation is described in detail. The observed spectral regions include particularly the 4571-A intercombination line and the b 2 and b 4 triplet lines of Mg I. Valuable spectral sequences were obtained at second contact with exposure rates from 19 to 5 frames/sec, corresponding to a height resolution of 15-50 km on the sun. This material provides us with an extended basis for the theoretical interpretation of the solar spectrum. Also, a peculiar phenomenon was noticed in the spectra; just before second contact most absorption lines becames tilted with respect to the nearby emission lines. The 16-mm movie made shows very marked changes in the line profiles at the solar limb. (Auth.)

  11. IPS observations of transient interplanetary phenomena associated with solar filament activity in late august

    International Nuclear Information System (INIS)

    Watanabe, Takashi; Marubashi, Katsuhide.

    1985-01-01

    Large-scale structures of the solar wind plasma during the severe geomagnetic storm of August 27-29, 1978 are studied on the basis of IPS and spacecraft observations. Three-dimensional configuration of an interplanetary disturbance which caused the SSC of August 27, 1978 was an oblate sphere having an axial ratio of 1.7. Approximate excess mass and kinetic energy contained within the high-speed portion of the disturbance (--500 km s -1 ) were 10 16 g and 3 x 10 31 erg, respectively. An interplanetary disturbance was also observed on August 28, 1978 during the main phase of the geomagnetic storm. It is suggested that the solar-filament activity which took place near the solar disk center in August 23-25, 1978 caused these interplanetary disturbances. (author)

  12. Solar Ion Processing of Itokawa Grains: Reconciling Model Predictions with Sample Observations

    Science.gov (United States)

    Christoffersen, Roy; Keller, L. P.

    2014-01-01

    Analytical TEM observations of Itokawa grains reported to date show complex solar wind ion processing effects in the outer 30-100 nm of pyroxene and olivine grains. The effects include loss of long-range structural order, formation of isolated interval cavities or "bubbles", and other nanoscale compositional/microstructural variations. None of the effects so far described have, however, included complete ion-induced amorphization. To link the array of observed relationships to grain surface exposure times, we have adapted our previous numerical model for progressive solar ion processing effects in lunar regolith grains to the Itokawa samples. The model uses SRIM ion collision damage and implantation calculations within a framework of a constant-deposited-energy model for amorphization. Inputs include experimentally-measured amorphization fluences, a Pi steradian variable ion incidence geometry required for a rotating asteroid, and a numerical flux-versus-velocity solar wind spectrum.

  13. Ellerman bombs observed with the new vacuum solar telescope and the atmospheric imaging assembly onboard the solar dynamics observatory

    Science.gov (United States)

    Chen, Yajie; Tian, Hui; Xu, Zhi; Xiang, Yongyuan; Fang, Yuliang; Yang, Zihao

    2017-12-01

    Ellerman bombs (EBs) are believed to be small-scale reconnection events occurring around the temperature minimum region in the solar atmosphere. They are often identified as significant enhancements in the extended Hα wings without obvious signatures in the Hα core. Here we explore the possibility of using the 1700 Å images taken by the Atmospheric Imaging Assembly (AIA) onboard the Solar Dynamics Observatory (SDO) to study EBs. From the Hα wing images obtained with the New Vacuum Solar Telescope (NVST) on 2015 May 2, we have identified 145 EBs and 51% of them clearly correspond to the bright points (BPs) in the AIA 1700 Å images. If we resize the NVST images using a linear interpolation to make the pixel sizes of the AIA and NVST images the same, some previously identified EBs disappear and about 71% of the remaining EBs are associated with BPs. Meanwhile, 66% of the compact brightenings in the AIA 1700 Å images can be identified as EBs in the Hα wings. The intensity enhancements of the EBs in the Hα wing images reveal a linear correlation with those of the BPs in the AIA 1700 Å images. Our study suggests that a significant fraction of EBs can be observed with the AIA 1700 Å filter, which is promising for large-sample statistical study of EBs as the seeing-free and full-disk SDO/AIA data are routinely available.

  14. A new CM SAF Solar Surface Radiation Climate Data Set derived from Meteosat Satellite Observations

    Science.gov (United States)

    Trentmann, J.; Mueller, R. W.; Pfeifroth, U.; Träger-Chatterjee, C.; Cremer, R.

    2014-12-01

    The incoming surface solar radiation has been defined as an essential climate variable by GCOS. It is mandatory to monitor this part of the earth's energy balance, and thus gain insights on the state and variability of the climate system. In addition, data sets of the surface solar radiation have received increased attention over the recent years as an important source of information for the planning of solar energy applications. The EUMETSAT Satellite Application Facility on Climate Monitoring (CM SAF) is deriving surface solar radiation from geostationary and polar-orbiting satellite instruments. While CM SAF is focusing on the generation of high-quality long-term climate data records, also operationally data is provided in short time latency within 8 weeks. Here we present SARAH (Solar Surface Radiation Dataset - Heliosat), i.e. the new CM SAF Solar Surface Radiation data set based on Meteosat satellite observations. SARAH provides instantaneous, daily- and monthly-averaged data of the effective cloud albedo (CAL), the direct normalized solar radiation (DNI) and the solar irradiance (SIS) from 1983 to 2013 for the full view of the Meteosat satellite (i.e, Europe, Africa, parts of South America, and the Atlantic ocean). The data sets are generated with a high spatial resolution of 0.05 deg allowing for detailed regional studies, and are available in netcdf-format at no cost without restrictions at www.cmsaf.eu. We provide an overview of the data sets, including a validation against reference measurements from the BSRN and GEBA surface station networks.

  15. A Cometary Bow Shock and Mid-Infrared Emission Variations Revealed in Spitzer Observations of HD 34078 and IC 405

    OpenAIRE

    France, Kevin; McCandliss, Stephan R.; Lupu, Roxana E.

    2006-01-01

    We present new infrared observations of the emission/reflection nebula IC 405 obtained with the Spitzer Space Telescope. Infrared images in the four IRAC bands (3.6, 4.5, 5.8, and 8.0 um) and two MIPS bands (24 and 70 um) are complemented by IRS spectroscopy (5-30 um) of two nebular filaments. The IRAC (8.0 um) and MIPS imaging shows evidence of a bow shock associated with the runaway O9.5V star, HD 34078, created by the interaction between the star and nebular material. The ratio of emission...

  16. Infrared spectroscopy and density functional theory investigation of calcite, chalk, and coccoliths-do we observe the mineral surface?

    DEFF Research Database (Denmark)

    Andersson, Martin Peter; Hem, Caroline Piper; Schultz, Logan Nicholas

    2014-01-01

    broadening from macroscopic dielectric effects. We detect water adsorbed on the high surface area synthetic calcite, which permits observation of the chemistry of thin liquid films on calcite using transmission infrared spectroscopy. The combination of infrared spectroscopy and density functional theory also...... asymmetric for the coccoliths and the synthetic calcite prepared using the carbonation method. It can be very well fitted by two peaks: a narrow Lorenzian at lower frequency and a broader Gaussian at higher frequency. These two samples both have a high specific surface area. Density functional theory...

  17. A cylindrical current sheet over the South solar pole observed by Ulysses

    Science.gov (United States)

    Khabarova, Olga; Kislov, Roman; Malova, Helmi; Obridko, Vladimir

    2016-04-01

    We provide the first evidence for the existence of a quasi-stable cylindrical current sheet over the South solar pole as observed by Ulysses in 2006, near the solar minimum, when it reached maximal heliolatitude of 79.7 degrees at 2.4 AU. It took place inside a fast speed stream from the coronal hole, and the tube was presumably crossed rather far from the center within two degrees of heliolatitude and ~10 degrees of heliolongitude. During the spacecraft passage throughout the structure, the solar wind velocity was approximately twice as little, the solar wind density was 20 times lower than the surrounded plasma values, but the temperature was twice as large in the point closest to the pole. The interplanetary magnetic field (IMF) strongly decreased due to sharp variations in the IMF radial component (RTN) that changed its sign twice, but other components did not show changes out of usual stochastic behavior. Both the behavior of the IMF, rotation of the plasma flow direction and other features indicate the occurrence of cylindrical current sheet. We discuss its solar origin and present modeling that can explain the observations.

  18. Solar radiation in Germany - observed trends and an assessment of their causes. Pt. 1; Regional approach

    Energy Technology Data Exchange (ETDEWEB)

    Liepert, B [Muenchen Univ., Freising (Germany). Lehrstuhl fuer Bioklimatologie und Immissionsforschung; Fabian, P [Muenchen Univ., Freising (Germany). Lehrstuhl fuer Bioklimatologie und Immissionsforschung; Grassl, H [Max-Planck-Institut fuer Meteorologie, Hamburg (Germany)

    1994-02-01

    The possible longterm variation of daily sums of global solar radiation (direct plus diffuse solar radiation) in West-Germany was analysed for twelve stations of the German Weather Service (DWD). The global solar radiation decreased remarkably at seven stations (List/Sylt, Norderney, Hamburg, Braunlage, Wuerzburg, Weihenstephan, Hohenpeissenberg) and showed no significant variations at the remaining five stations (Braunschweig, Bocholt, Gelsenkirchen, Trier and Freiburg). The average decline is 3.7[+-]1.3% per decade in the last 15 to 39 years. The locally varying causes for the decline are changes in cloud parameters, fog occurrence and tropospheric aerosol. In this part of the article some possible causes, such as solar variability, increased number of contrails, decreased surface reflectivity, increased volcanic aerosol load in the 1980's or increased water vapour column content could be excluded. With a more sophisticated statistical procedure the effect of changes in cloud parameters and the effect of changed clear sky turbidity could not only be separated for each month for Hohenpeissenberg and Wuerzburg but also made mainly responsible for the observed trend. In Part II (Grabbe, Grassl), more detailed observations of solar radiation hourly averages of Hamburg were analysed. (orig.)

  19. Observational Evidence for the Associated Formation of Blobs and Raining Inflows in the Solar Corona

    International Nuclear Information System (INIS)

    Sanchez-Diaz, E.; Rouillard, A. P.; Lavraud, B.; Pinto, R. F.; Plotnikov, I.; Genot, V.; Davies, J. A.; Sheeley, N. R.; Kilpua, E.

    2017-01-01

    The origin of the slow solar wind is still a topic of much debate. The continual emergence of small transient structures from helmet streamers is thought to constitute one of the main sources of the slow wind. Determining the height at which these transients are released is an important factor in determining the conditions under which the slow solar wind forms. To this end, we have carried out a multipoint analysis of small transient structures released from a north–south tilted helmet streamer into the slow solar wind over a broad range of position angles during Carrington Rotation 2137. Combining the remote-sensing observations taken by the Solar-TErrestrial RElations Observatory ( STEREO ) mission with coronagraphic observations from the SOlar and Heliospheric Observatory ( SOHO ) spacecraft, we show that the release of such small transient structures (often called blobs), which subsequently move away from the Sun, is associated with the concomitant formation of transient structures collapsing back toward the Sun; the latter have been referred to by previous authors as “raining inflows.” This is the first direct association between outflowing blobs and raining inflows, which locates the formation of blobs above the helmet streamers and gives strong support that the blobs are released by magnetic reconnection.

  20. Observational Evidence for the Associated Formation of Blobs and Raining Inflows in the Solar Corona

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Diaz, E.; Rouillard, A. P.; Lavraud, B.; Pinto, R. F.; Plotnikov, I.; Genot, V. [Institut de Recherche en Astrophysique et Planétologie, Paul Sabatier University, Toulouse, 9 avenue Colonel Roche, BP 44346-31028, Toulouse Cedex 4A (France); Davies, J. A. [RAL Space, STFC-Rutherford Appleton Laboratory, Harwell Campus, Science and Technology Facilities Council Rutherford Appleton Laboratory, Harwell Campus, Didcot OX11 0QX (United Kingdom); Sheeley, N. R. [Space Science Division, Naval Research Laboratory, Naval Research Laboratory, Code 7600, 4555 Overlook Avenue SW, Washington, DC 20375 (United States); Kilpua, E., E-mail: eduardo.sanchez-diaz@irap.omp.eu, E-mail: alexis.rouillard@irap.omp.eu, E-mail: benoit.lavraud@irap.omp.eu, E-mail: rui.pinto@irap.omp.eu, E-mail: illya.plotnikov@irap.omp.eu, E-mail: vincent.genot@irap.omp.eu, E-mail: jackie.davies@stfc.ac.uk, E-mail: neil.sheeley@nrl.navy.mil, E-mail: emilia.kilpua@helsinki.fi [Space Physics Department, Department of Physics, P.O. Box 64 FI-00014, University of Helsinki, Helsinki (Finland)

    2017-01-20

    The origin of the slow solar wind is still a topic of much debate. The continual emergence of small transient structures from helmet streamers is thought to constitute one of the main sources of the slow wind. Determining the height at which these transients are released is an important factor in determining the conditions under which the slow solar wind forms. To this end, we have carried out a multipoint analysis of small transient structures released from a north–south tilted helmet streamer into the slow solar wind over a broad range of position angles during Carrington Rotation 2137. Combining the remote-sensing observations taken by the Solar-TErrestrial RElations Observatory ( STEREO ) mission with coronagraphic observations from the SOlar and Heliospheric Observatory ( SOHO ) spacecraft, we show that the release of such small transient structures (often called blobs), which subsequently move away from the Sun, is associated with the concomitant formation of transient structures collapsing back toward the Sun; the latter have been referred to by previous authors as “raining inflows.” This is the first direct association between outflowing blobs and raining inflows, which locates the formation of blobs above the helmet streamers and gives strong support that the blobs are released by magnetic reconnection.

  1. Optical and near-infrared observations of SN 2011dh - The first 100 days

    Science.gov (United States)

    Ergon, M.; Sollerman, J.; Fraser, M.; Pastorello, A.; Taubenberger, S.; Elias-Rosa, N.; Bersten, M.; Jerkstrand, A.; Benetti, S.; Botticella, M. T.; Fransson, C.; Harutyunyan, A.; Kotak, R.; Smartt, S.; Valenti, S.; Bufano, F.; Cappellaro, E.; Fiaschi, M.; Howell, A.; Kankare, E.; Magill, L.; Mattila, S.; Maund, J.; Naves, R.; Ochner, P.; Ruiz, J.; Smith, K.; Tomasella, L.; Turatto, M.

    2014-02-01

    We present optical and near-infrared (NIR) photometry and spectroscopy of the Type IIb supernova (SN) 2011dh for the first 100 days. We complement our extensive dataset with Swift ultra-violet (UV) and Spitzer mid-infrared (MIR) data to build a UV to MIR bolometric lightcurve using both photometric and spectroscopic data. Hydrodynamical modelling of the SN based on this bolometric lightcurve have been presented in Bersten et al. (2012, ApJ, 757, 31). We find that the absorption minimum for the hydrogen lines is never seen below ~11 000 km s-1 but approaches this value as the lines get weaker. This suggests that the interface between the helium core and hydrogen rich envelope is located near this velocity in agreement with the Bersten et al. (2012) He4R270 ejecta model. Spectral modelling of the hydrogen lines using this ejecta model supports the conclusion and we find a hydrogen mass of 0.01-0.04 M⊙ to be consistent with the observed spectral evolution. We estimate that the photosphere reaches the helium core at 5-7 days whereas the helium lines appear between ~10 and ~15 days, close to the photosphere and then move outward in velocity until ~40 days. This suggests that increasing non-thermal excitation due to decreasing optical depth for the γ-rays is driving the early evolution of these lines. The Spitzer 4.5 μm band shows a significant flux excess, which we attribute to CO fundamental band emission or a thermal dust echo although further work using late time data is needed. Thedistance and in particular the extinction, where we use spectral modelling to put further constraints, is discussed in some detail as well as the sensitivity of the hydrodynamical modelling to errors in these quantities. We also provide and discuss pre- and post-explosion observations of the SN site which shows a reduction by ~75 percent in flux at the position of the yellow supergiant coincident with SN 2011dh. The B, V and r band decline rates of 0.0073, 0.0090 and 0.0053 mag day-1

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

    International Nuclear Information System (INIS)

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

    2011-01-01

    We present grism spectra of emission-line galaxies (ELGs) from 0.6 to 1.6 μm from the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope. These new infrared grism data augment previous optical Advanced Camera for Surveys G800L 0.6-0.95 μm grism data in GOODS-South from the PEARS program, extending the wavelength coverage well past the G800L red cutoff. The Early Release Science (ERS) grism field was observed at a depth of two orbits per grism, yielding spectra of hundreds of faint objects, a subset of which is presented here. ELGs are studied via the Hα, [O III], and [O II] emission lines detected in the redshift ranges 0.2 ∼ B(F098M) ≅ 25 mag. Seventeen GOODS-South galaxies that previously only had photometric redshifts now have new grism-spectroscopic redshifts, in some cases with large corrections to the photometric redshifts (Δz ≅ 0.3-0.5). Additionally, one galaxy had no previously measured redshift but now has a secure grism-spectroscopic redshift, for a total of 18 new GOODS-South spectroscopic redshifts. The faintest source in our sample has a magnitude m AB(F098M) = 26.9 mag. The ERS grism data also reflect the expected trend of lower specific star formation rates for the highest mass galaxies in the sample as a function of redshift, consistent with downsizing and discovered previously from large surveys. These results demonstrate the remarkable efficiency and capability of the WFC3 NIR grisms for measuring galaxy properties to faint magnitudes and redshifts to z ∼> 2.

  3. Current Observational Constraints to Holographic Dark Energy Model with New Infrared cut-off via Markov Chain Monte Carlo Method

    OpenAIRE

    Wang, Yuting; Xu, Lixin

    2010-01-01

    In this paper, the holographic dark energy model with new infrared (IR) cut-off for both the flat case and the non-flat case are confronted with the combined constraints of current cosmological observations: type Ia Supernovae, Baryon Acoustic Oscillations, current Cosmic Microwave Background, and the observational hubble data. By utilizing the Markov Chain Monte Carlo (MCMC) method, we obtain the best fit values of the parameters with $1\\sigma, 2\\sigma$ errors in the flat model: $\\Omega_{b}h...

  4. Anomalous Temporal Behaviour of Broadband Ly Alpha Observations During Solar Flares from SDO/EVE

    Science.gov (United States)

    Milligan, Ryan O.; Chamberlin, Phillip C.

    2016-01-01

    Although it is the most prominent emission line in the solar spectrum, there has been a notable lack of studies devoted to variations in Lyman-alpha (Ly-alpha) emission during solar flares in recent years. However, the few examples that do exist have shown Ly-alpha emission to be a substantial radiator of the total energy budget of solar flares (of the order of 10 percent). It is also a known driver of fluctuations in the Earth's ionosphere. The EUV (Extreme Ultra-Violet) Variability Experiment (EVE) on board the Solar Dynamics Observatory (SDO) now provides broadband, photometric Ly-alpha data at 10-second cadence with its Multiple EUV Grating Spectrograph-Photometer (MEGS-P) component, and has observed scores of solar flares in the 5 years since it was launched. However, the MEGS-P time profiles appear to display a rise time of tens of minutes around the time of the flare onset. This is in stark contrast to the rapid, impulsive increase observed in other intrinsically chromospheric features (H-alpha, Ly-beta, LyC, C III, etc.). Furthermore, the emission detected by MEGS-P peaks around the time of the peak of thermal soft X-ray emission and not during the impulsive phase when energy deposition in the chromosphere (often assumed to be in the form of non-thermal electrons) is greatest. The time derivative of Ly-alpha lightcurves also appears to resemble that of the time derivative of soft X-rays, reminiscent of the Neupert effect. Given that spectrally-resolved Ly-alpha observations during flares from SORCE / SOLSTICE (Solar Radiation and Climate Experiment / Solar Stellar Irradiance Comparison Experiment) peak during the impulsive phase as expected, this suggests that the atypical behaviour of MEGS-P data is a manifestation of the broadband nature of the observations. This could imply that other lines andor continuum emission that becomes enhanced during flares could be contributing to the passband. Users are hereby urged to exercise caution when interpreting

  5. On the solar origin of interplanetary disturbances observed in the vicinity of the Earth

    Directory of Open Access Journals (Sweden)

    N. Vilmer

    Full Text Available The solar origin of 40 interplanetary disturbances observed in the vicinity of the Earth between January 1997 and June 1998 is investigated in this paper. Analysis starts with the establishment of a list of Interplanetary Mass Ejections or ICMEs (magnetic clouds, flux ropes and ejecta and of Interplanetary Shocks measured at WIND for the period for which we had previously investigated the coupling of the interplanetary medium with the terrestrial ionospheric response. A search for associated coronal mass ejections (CMEs observed by LASCO/SOHO is then performed, starting from an estimation of the transit time of the inter-planetary perturbation from the Sun to the Earth, assumed to be achieved at a constant speed (i.e. the speed measured at 1 AU. EIT/SOHO and Nançay Radioheliograph (NRH observations are also used as proxies in this identification for the cases when LASCO observations do not allow one to firmly establish the association. The last part of the analysis concerns the identification of the solar source of the CMEs, performed using a large set of solar observations from X-ray to radio wavelengths. In the present study, this association is based on a careful examination of many data sets (EIT, NRH and H images and not on the use of catalogs and of Solar Geophysical Data reports. An association between inter-planetary disturbances and LASCO/CMEs or proxies on the disk is found for 36 interplanetary events. For 32 events, the solar source of activity can also be identified. A large proportion of cases is found to be associated with a flare signature in an active region, not excluding of course the involvement of a filament. Conclusions are finally drawn on the propagation of the disturbances in the interplanetary medium, the preferential association of disturbances detected close to the Earth’s orbit with halos or wide CMEs and the location on the solar disk of solar sources of the interplanetary disturbances during that period

  6. Near infrared emission of TbAG:Ce{sup 3+},Yb{sup 3+} phosphor for solar cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Meshram, N. D., E-mail: meshramnileshsd@gmail.com [Shri. Mathuradas Mohota College of Science, Sakkardara Square, Nagpur-440009 (India); Yadav, P. J., E-mail: yadav.pooja75@yahoo.in [Department of Electronics, Nagpur University campus, Nagpur-440010 (India); Pathak, A. A., E-mail: aapathak@yahoo.com [National power Training Institute, South ambazari road, Nagpur-440022 (India); Joshi, C. P., E-mail: charusheela-4253@yahoo.co.in [Ramdeobaba College of Engineering and Management, Katol road, Gittikhadan Nagpur-440012 (India); Moharil, S. V., E-mail: svmoharil@yahoo.com [Department of Physics, Nagpur University campus, Nagpur-440010 (India)

    2016-05-06

    Luminescent materials doped with rare earth ions are used for many devices such as optical amplifiers in telecommunication, phosphors for white light emitting diodes (LEDs), displays, and so on. Recently, they also have attracted a great interest for photovoltaic applications to improve solar cell efficiency by modifying solar spectrum. Crystal silicon (c-Si) solar cells most effectively convert photons of energy close to the semiconductor band gap. The mis-match between the incident solar spectrum and the spectral response of solar cells is one of the main reasons to limit the cell efficiency. The efficiency limit of the c-Si has been estimated to be 29% by Shockley and Queisser. However, this limit is estimated to be improved up to 38.4% by modifying the solar spectrum by a quantum cutting (down converting) phosphor which converts one photon of high energy into two photons of lower energy. The phenomenon such as the quantum cutting or the down conversion of rare earth ions have been investigated since Dexter reported the possibility of a luminescent quantum yield greater than unity in 1957. In the past, the quantum cutting from a vacuum ultraviolet photon to visible photons for Pr{sup 3+}, Gd{sup 3+},Gd{sup 3+}–Eu{sup 3+}, and Er{sup 3+}–Tb{sup 3+} had been studied. Recently, a new quantum cutting phenomenon from visible photon shorter than 500 nm to two infrared photons for Tb{sup 3+}–Yb{sup 3+}, Pr{sup 3+}–Yb{sup 3+}, and Tm{sup 3+}–Yb{sup 3+} has been reported. The Yb{sup 3+} ion is suitable as an acceptor and emitter because luminescent quantum efficiency of Yb{sup 3+} is close to 100% and the energy of the only excited level of Yb{sup 3+} (1.2 eV) is roughly in accordance with the band gap of Si (1.1 eV). In addition, the Ce{sup 3+}-doped Tb{sub 3}Al{sub 5}O{sub 12} (TbAG), used as a phosphor for white LED, has broad absorption bands in the range of 300–500 nm due to strong ligand field and high luminescent quantum efficiency. Therefore, the

  7. Charge state evolution in the solar wind. III. Model comparison with observations

    Energy Technology Data Exchange (ETDEWEB)

    Landi, E.; Oran, R.; Lepri, S. T.; Zurbuchen, T. H.; Fisk, L. A.; Van der Holst, B. [Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, MI 48109 (United States)

    2014-08-01

    We test three theoretical models of the fast solar wind with a set of remote sensing observations and in-situ measurements taken during the minimum of solar cycle 23. First, the model electron density and temperature are compared to SOHO/SUMER spectroscopic measurements. Second, the model electron density, temperature, and wind speed are used to predict the charge state evolution of the wind plasma from the source regions to the freeze-in point. Frozen-in charge states are compared with Ulysses/SWICS measurements at 1 AU, while charge states close to the Sun are combined with the CHIANTI spectral code to calculate the intensities of selected spectral lines, to be compared with SOHO/SUMER observations in the north polar coronal hole. We find that none of the theoretical models are able to completely reproduce all observations; namely, all of them underestimate the charge state distribution of the solar wind everywhere, although the levels of disagreement vary from model to model. We discuss possible causes of the disagreement, namely, uncertainties in the calculation of the charge state evolution and of line intensities, in the atomic data, and in the assumptions on the wind plasma conditions. Last, we discuss the scenario where the wind is accelerated from a region located in the solar corona rather than in the chromosphere as assumed in the three theoretical models, and find that a wind originating from the corona is in much closer agreement with observations.

  8. Report on the Dutch expedition to observe the 1973 June 30 solar eclipse. II

    International Nuclear Information System (INIS)

    Houtgast, J.; Namba, O.

    1979-01-01

    This paper continues to report the Dutch expedition to Atar, Mauritania, to observe the total solar eclipse of June 30, 1973. The purpose of this expedition was to obtain spectra from the transition region photosphere-chromosphere with high spectral and time resolution. (Auth.)

  9. Novel Solar Sail Mission Concepts for High-Latitude Earth and Lunar Observation

    NARCIS (Netherlands)

    Heiligers, M.J.; Parker, Jeffrey S.; Macdonald, Malcolm

    2016-01-01

    This paper proposes the use of solar sail periodic orbits in the Earth-Moon system for ob-servation of the high-latitudes of the Earth and Moon. At the Earth, the high-latitudes will be crucial in answering questions concerning global climate change, monitoring space weather events and ensuring

  10. Charge state evolution in the solar wind. III. Model comparison with observations

    International Nuclear Information System (INIS)

    Landi, E.; Oran, R.; Lepri, S. T.; Zurbuchen, T. H.; Fisk, L. A.; Van der Holst, B.

    2014-01-01

    We test three theoretical models of the fast solar wind with a set of remote sensing observations and in-situ measurements taken during the minimum of solar cycle 23. First, the model electron density and temperature are compared to SOHO/SUMER spectroscopic measurements. Second, the model electron density, temperature, and wind speed are used to predict the charge state evolution of the wind plasma from the source regions to the freeze-in point. Frozen-in charge states are compared with Ulysses/SWICS measurements at 1 AU, while charge states close to the Sun are combined with the CHIANTI spectral code to calculate the intensities of selected spectral lines, to be compared with SOHO/SUMER observations in the north polar coronal hole. We find that none of the theoretical models are able to completely reproduce all observations; namely, all of them underestimate the charge state distribution of the solar wind everywhere, although the levels of disagreement vary from model to model. We discuss possible causes of the disagreement, namely, uncertainties in the calculation of the charge state evolution and of line intensities, in the atomic data, and in the assumptions on the wind plasma conditions. Last, we discuss the scenario where the wind is accelerated from a region located in the solar corona rather than in the chromosphere as assumed in the three theoretical models, and find that a wind originating from the corona is in much closer agreement with observations.

  11. Multi-spacecraft observations of solar hard X-ray bursts

    International Nuclear Information System (INIS)

    Kane, S.R.

    1981-01-01

    The role of multi-spacecraft observations in solar flare research is examined from the point of view of solar hard X-ray bursts and their implications with respect to models of the impulsive phase. Multi-spacecraft measurements provide a stereoscopic view of the flare region, and hence represent the only direct method of measuring directivity of X-rays. In absence of hard X-ray imaging instruments with high spatial and temporal resolution, multi-spacecraft measurements provide the only means of determining the radial (vertical) structure of the hard X-ray source. This potential of the multi-spacecraft observations is illustrated with an analysis of the presently available observations of solar hard X-ray bursts made simultaneously by two or more of the following spacecraft: International Sun Earth Explorer-3 (ISEE-3), Pioneer Venus Orbiter (PVO), Helios-B and High Energy Astrophysical Observatory-A (HEAO-A). In particular, some conclusions have been drawn about the spatial structure and directivity of 50-100 keV X-rays from impulsive flares. Desirable features of future multi-spacecraft missions are briefly discussed followed by a short description of the hard X-ray experiment on the International Solar Polar Mission which has been planned specifically for multi-spacecraft observations of the Sun. (orig.)

  12. Imaging and spectroscopic observations of the 9 March 2016 Total Solar Eclipse in Palangkaraya

    International Nuclear Information System (INIS)

    Kholish, Abdul Majid Al; Jihad, Imanul; Andika, Irham Taufik; Puspitaningrum, Evaria; Ainy, Fathin Q.; Ramadhan, Sahlan; Arifyanto, M. Ikbal; Malasan, Hakim L.

    2016-01-01

    The March 9 th 2016 total solar eclipse observation was carried out at Universitas Palangkaraya, Central Kalimantan. Time-resolved imaging of the Sun has been conducted before, after, and during totality of eclipse while optical spectroscopic observation has been carried out only at the totality. The imaging observation in white light was done to take high resolution images of solar corona. The images were taken with a DSLR camera that is attached to a refractor telescope (d=66 mm, f/5.9). Despite cloudy weather during the eclipse moments, we managed to obtain the images with lower signal-to-noise ratio, including identifiable diamond ring, prominence and coronal structure. The images were processed using standard reduction procedure to increase the signal-to-noise ratio and to enhance the corona. Then, the coronal structure is determined and compared with ultraviolet data from SOHO to analyze the correlation between visual and ultraviolet corona. The spectroscopic observation was conducted using a slit-less spectrograph and a DSLR camera to obtain solar flash spectra. The flash spectra taken during the eclipse show emissions of H 4861 Å, He I 5876 Å, and H 6563 Å. The Fe XIV 5303 Å and Fe X 6374 Å lines are hardly detected due to low signal-to-noise ratio. Spectral reduction and analysis are conducted to derive the emission lines intensity relative to continuum intensity. We use the measured parameters to determine the temperature of solar chromosphere. (paper)

  13. Coherent structures at ion scales in fast and slow solar wind: Cluster observations

    Science.gov (United States)

    Perrone, D.; Alexandrova, O.; Zouganelis, Y.; Roberts, O.; Lion, S.; Escoubet, C. P.; Walsh, A. P.; Maksimovic, M.; Lacombe, C.

    2017-12-01

    Spacecraft measurements generally reveal that solar wind electromagnetic fluctuations are in a state of fully-developed turbulence. Turbulence represents a very complex problem in plasmas since cross-scale coupling and kinetic effects are present. Moreover, the intermittency phenomenon, i.e. the manifestation of the non-uniform and inhomogeneous energy transfer and dissipation in a turbulent system, represents a very important aspect of the solar wind turbulent cascade. Here, we study coherent structures responsible for solar wind intermittency around ion characteristic scales. We find that, in fast solar wind, intermittency is due to Alfvén vortex-like structures and current sheets. In slow solar wind, we observe as well compressive structures like magnetic solitons, holes and shocks. By using high-time resolution magnetic field data of multi-point measurements of Cluster spacecraft, we characterize the observed coherent structures in terms of topology and propagation speed. We show that all structures around ion characteristic scales, both in fast and slow solar wind, are characterized by a strong wave-vector anisotropy in the perpendicular direction with respect to the local magnetic field. Moreover, some of them propagate in the plasma rest frame in the direction perpendicular to the local field. Finally, a further analysis on the electron and ion velocity distributions shows a high variability; in particular, close to coherent structures the electron and ion distribution functions appear strongly deformed and far from the thermodynamic equilibrium. Possible interpretations of the observed structures and their role in the heating process of the plasma are also discussed.

  14. Solar Tower Experiments for Radiometric Calibration and Validation of Infrared Imaging Assets and Analysis Tools for Entry Aero-Heating Measurements

    Science.gov (United States)

    Splinter, Scott C.; Daryabeigi, Kamran; Horvath, Thomas J.; Mercer, David C.; Ghanbari, Cheryl M.; Ross, Martin N.; Tietjen, Alan; Schwartz, Richard J.

    2008-01-01

    The NASA Engineering and Safety Center sponsored Hypersonic Thermodynamic Infrared Measurements assessment team has a task to perform radiometric calibration and validation of land-based and airborne infrared imaging assets and tools for remote thermographic imaging. The IR assets and tools will be used for thermographic imaging of the Space Shuttle Orbiter during entry aero-heating to provide flight boundary layer transition thermography data that could be utilized for calibration and validation of empirical and theoretical aero-heating tools. A series of tests at the Sandia National Laboratories National Solar Thermal Test Facility were designed for this task where reflected solar radiation from a field of heliostats was used to heat a 4 foot by 4 foot test panel consisting of LI 900 ceramic tiles located on top of the 200 foot tall Solar Tower. The test panel provided an Orbiter-like entry temperature for the purposes of radiometric calibration and validation. The Solar Tower provided an ideal test bed for this series of radiometric calibration and validation tests because it had the potential to rapidly heat the large test panel to spatially uniform and non-uniform elevated temperatures. Also, the unsheltered-open-air environment of the Solar Tower was conducive to obtaining unobstructed radiometric data by land-based and airborne IR imaging assets. Various thermocouples installed on the test panel and an infrared imager located in close proximity to the test panel were used to obtain surface temperature measurements for evaluation and calibration of the radiometric data from the infrared imaging assets. The overall test environment, test article, test approach, and typical test results are discussed.

  15. Observations of solar flare transition zone plasmas from the Solar Maximum Mission

    Science.gov (United States)

    Cheng, C.-C.; Bruner, E. C.; Tandberg-Hanssen, E.; Woodgate, B. E.; Shine, R. A.; Kenny, P. J.; Henze, W.; Poletto, G.

    1982-01-01

    The spatial and temporal evolution of the Si IV and O IV intensity, density and mass motions in preflare and flare transition zone plasmas are studied for the case of the April 8, 1980 flare. It is found that: (1) the UV flare observed in the Si IV and O IV lines is unambiguously identified as occurring in a low-lying, preexisting transition zone loop which spanned the magnetic neutral line separating a larger leader spot and a newly emerged, isolated spot of opposite polarity; (2) at the onset of the flare, the easternmost footpoint, which was anchored in an isolated spot region of high longitudinal magnetic field gradient, showed sudden, impulsive brightening with large intensity increases; and (3) the release flare energy was transported by way of large-scale connecting field lines to other parts of the active region, producing the hot plasma and H-alpha kernels observed near the trailing spot.

  16. The High Energy Photons Emission from Solar Flares Observed by SZ2-XD

    Science.gov (United States)

    Wang, Huanyu; Li, Xinqiao; Ma, Yuqian; Zhang, Chengmo; Xu, Yupeng; Wang, Jingzhou; Chen, Guoming

    The spectra and light curve of near a hundred Solar X-ray Flare events, which were observed by SZ2/XD in the energy band of 10-800 keV during 2001, have been investigated. The events covered from C to X-class flares, which are shown different characters of high energy photons emission. The results will be presented in this paper. The discussions will be made especially for 3 of the brightest X-class solar flares SF010402(X20),SF010406(X5.6) and SF010415 (X14.4, a GLE event).

  17. Local tests of gravitation with Gaia observations of Solar System Objects

    Science.gov (United States)

    Hees, Aurélien; Le Poncin-Lafitte, Christophe; Hestroffer, Daniel; David, Pedro

    2018-04-01

    In this proceeding, we show how observations of Solar System Objects with Gaia can be used to test General Relativity and to constrain modified gravitational theories. The high number of Solar System objects observed and the variety of their orbital parameters associated with the impressive astrometric accuracy will allow us to perform local tests of General Relativity. In this communication, we present a preliminary sensitivity study of the Gaia observations on dynamical parameters such as the Sun quadrupolar moment and on various extensions to general relativity such as the parametrized post-Newtonian parameters, the fifth force formalism and a violation of Lorentz symmetry parametrized by the Standard-Model extension framework. We take into account the time sequences and the geometry of the observations that are particular to Gaia for its nominal mission (5 years) and for an extended mission (10 years).

  18. The solar eruption of 13 May 2005: EISCAT and MERLIN observations of a coronal radio burst

    Directory of Open Access Journals (Sweden)

    R. A. Jones

    2006-09-01

    Full Text Available We report results from EISCAT and MERLIN observations of radio scintillation during a solar eruptive event in May 2005. Anomalous increases in signal strength detected at sites more than 2000 km apart are shown to arise from the detection of a strong coronal radio burst in the distant off-axis response of the MERLIN and EISCAT antennas. These observations show that EISCAT is capable of detecting the signatures of explosive events in the solar atmosphere with a high degree of time resolution. We further suggest that the highly time-structured variation in signal strength caused by distant off-axis detection of a powerful coronal radio signal could provide an explanation for previously unexplained anomalies in EISCAT IPS observations, as well as being a potential source of errors in active observations using radar codes with a completion time longer than the time-variation of the coronal signal.

  19. Thermodynamics of the Solar Corona and Evolution of the Solar Magnetic Field as Inferred from the Total Solar Eclipse Observations of 11 July 2010

    Science.gov (United States)

    Habbal, Shadia Rifai; Druckmueller, Miloslav; Morgan, Huw; Ding, Adalbert; Johnson, Judd; Druckmuellerova, Hana; Daw, Adrian; Arndt, Martina B.; Dietzel, Martin; Saken, Jon

    2011-01-01

    We report on multi-wavelength observations of the corona taken simultaneously in broadband white light, and in seven spectral lines, H-alpha 656.3 nm, Fe IX 435.9 nm, Fe X 637.4 nm, Fe XI 789.2 nm, Fe XIII 1074.7 nm, Fe XIV 530.3 nm and Ni XV 670.2 nm. The observations were made during the total solar eclipse of 11 July 2010 from the atoll of Tatakoto in French Polynesia. Simultaneous imaging with narrow bandpass filters in each of these spectral lines and in their corresponding underlying continua maximized the observing time during less than ideal observing conditions and yielded outstanding quality data. The application of two complementary image processing techniques revealed the finest details of coronal structures at 1" resolution in white light, and 6.5" in each of the spectral lines. This comprehensive wavelength coverage confirmed earlier eclipse findings that the solar corona has a clear two-temperature structure: The open field lines, expanding outwards from the solar surface, are characterized by electron temperatures near 1 X 10(exp 6) K, while the hottest plasma around 2X 10(exp 6) K resides in loop-like structures forming the bulges of streamers. The first images of the corona in the forbidden lines of Fe IX and Ni XV, showed that there was very little coronal plasma at temperatures below 5 X 10(exp 5) K and above 2.5X 10(exp 6) K. The data also enabled temperature differentiations as low as 0:2 X 10(exp 6) K in different density structures. These observations showed how the passage of CMEs through the corona, prior to totality, produced large scale ripples and very sharp streaks, which could be identified with distinct temperatures for the first time. The ripples were most prominent in emission from spectral lines associated with temperatures around 10(exp 6) K. The most prominent streak was associated with a conical-shaped void in the emission from the coolest line of Fe IX and from the hottest line of Ni XV. A prominence, which erupted prior to

  20. Seismic analysis of four solar-like stars observed during more than eight months by Kepler

    DEFF Research Database (Denmark)

    Mathur, S.; L. Campante, T.; Handberg, R.

    2011-01-01

    Having started science operations in May 2009, the Kepler photometer has been able to provide exquisite data of solar-like stars. Five out of the 42 stars observed continuously during the survey phase show evidence of oscillations, even though they are rather faint (magnitudes from 10.5 to 12). I......). In this paper, we present an overview of the results of the seismic analysis of 4 of these stars observed during more than eight months....

  1. Seismic Analysis of Four Solar-like Stars Observed during More Than Eight Months by Kepler

    Science.gov (United States)

    Mathur, S.; Campante, T. L.; Handberg, R.; García, R. A.; Appourchaux, T.; Bedding, T. R.; Mosser, B.; Chaplin, W. J.; Ballot, J.; Benomar, O.; Bonanno, A.; Corsaro, E.; Gaulme, P.; Hekker, S.; Régulo, C.; Salabert, D.; Verner, G.; White, T. R.; Brandão, I. M.; Creevey, O. L.; Dogan, G.; Bazot, M.; Cunha, M. S.; Elsworth, Y.; Huber, D.; Hale, S. J.; Houdek, G.; Karoff, C.; Lundkvist, M.; Metcalfe, T. S.; Molenda-Zakowicz, J.; Monteiro, M. J. P. F. G.; Thompson, M. J.; Stello, D.; Christensen-Dalsgaard, J.; Gilliland, R. L.; Kawaler, S. D.; Kjeldsen, H.; Clarke, B. D.; Girouard, F. R.; Hall, J. R.; Quintana, E. V.; Sanderfer, D. T.; Seader, S. E.

    2012-09-01

    Having started science operations in May 2009, the Kepler photometer has been able to provide exquisite data for solar-like stars. Five out of the 42 stars observed continuously during the survey phase show evidence of oscillations, even though they are rather faint (magnitudes from 10.5 to 12). In this paper, we present an overview of the results of the seismic analysis of 4 of these stars observed during more than eight months.

  2. Infrared and X-ray observations of the decline of A 0620-00

    International Nuclear Information System (INIS)

    Citterio, O.; Conti, G.; Di Benedetto, P.; Tanzi, E.G.; Perola, G.C.; White, N.E.; Charles, P.A.; Sanford, P.W.

    1976-01-01

    Measurements of the 1.65- and 2.2-μ flux on five nights from October 3 to 31 and the 3 to 9 keV flux from October 7 to December 1 of the transient X-ray source A 0620-00 show a regular decline. The infrared flux is consistent with an extrapolation of a bremstrahlung spectrum fitted to the X-rays if the source is self-absorbed in the infrared, a situation similar to Sco X-I. (author)

  3. Where the Solar system meets the solar neighbourhood: patterns in the distribution of radiants of observed hyperbolic minor bodies

    Science.gov (United States)

    de la Fuente Marcos, Carlos; de la Fuente Marcos, Raúl; Aarseth, Sverre J.

    2018-05-01

    Observed hyperbolic minor bodies might have an interstellar origin, but they can be natives of the Solar system as well. Fly-bys with the known planets or the Sun may result in the hyperbolic ejection of an originally bound minor body; in addition, members of the Oort cloud could be forced to follow inbound hyperbolic paths as a result of secular perturbations induced by the Galactic disc or, less frequently, due to impulsive interactions with passing stars. These four processes must leave distinctive signatures in the distribution of radiants of observed hyperbolic objects, both in terms of coordinates and velocity. Here, we perform a systematic numerical exploration of the past orbital evolution of known hyperbolic minor bodies using a full N-body approach and statistical analyses to study their radiants. Our results confirm the theoretical expectations that strong anisotropies are present in the data. We also identify a statistically significant overdensity of high-speed radiants towards the constellation of Gemini that could be due to the closest and most recent known fly-by of a star to the Solar system, that of the so-called Scholz's star. In addition to and besides 1I/2017 U1 (`Oumuamua), we single out eight candidate interstellar comets based on their radiants' velocities.

  4. Observations of Reconnection Flows in a Flare on the Solar Disk

    International Nuclear Information System (INIS)

    Wang, Juntao; Simões, P. J. A.; Jeffrey, N. L. S.; Fletcher, L.; Wright, P. J.; Hannah, I. G.

    2017-01-01

    Magnetic reconnection is a well-accepted part of the theory of solar eruptive events, though the evidence is still circumstantial. Intrinsic to the reconnection picture of a solar eruptive event, particularly in the standard model for two-ribbon flares (CSHKP model), are an advective flow of magnetized plasma into the reconnection region, expansion of field above the reconnection region as a flux rope erupts, retraction of heated post-reconnection loops, and downflows of cooling plasma along those loops. We report on a unique set of Solar Dynamics Observatory /Atmospheric Imaging Assembly imaging and Hinode /EUV Imaging Spectrometer spectroscopic observations of the disk flare SOL2016-03-23T03:54 in which all four flows are present simultaneously. This includes spectroscopic evidence for a plasma upflow in association with large-scale expanding closed inflow field. The reconnection inflows are symmetric, and consistent with fast reconnection, and the post-reconnection loops show a clear cooling and deceleration as they retract. Observations of coronal reconnection flows are still rare, and most events are observed at the solar limb, obscured by complex foregrounds, making their relationship to the flare ribbons, cusp field, and arcades formed in the lower atmosphere difficult to interpret. The disk location and favorable perspective of this event have removed these ambiguities giving a clear picture of the reconnection dynamics.

  5. Observations of Reconnection Flows in a Flare on the Solar Disk

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Juntao; Simões, P. J. A.; Jeffrey, N. L. S.; Fletcher, L.; Wright, P. J.; Hannah, I. G., E-mail: j.wang.4@research.gla.ac.uk [SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom)

    2017-09-20

    Magnetic reconnection is a well-accepted part of the theory of solar eruptive events, though the evidence is still circumstantial. Intrinsic to the reconnection picture of a solar eruptive event, particularly in the standard model for two-ribbon flares (CSHKP model), are an advective flow of magnetized plasma into the reconnection region, expansion of field above the reconnection region as a flux rope erupts, retraction of heated post-reconnection loops, and downflows of cooling plasma along those loops. We report on a unique set of Solar Dynamics Observatory /Atmospheric Imaging Assembly imaging and Hinode /EUV Imaging Spectrometer spectroscopic observations of the disk flare SOL2016-03-23T03:54 in which all four flows are present simultaneously. This includes spectroscopic evidence for a plasma upflow in association with large-scale expanding closed inflow field. The reconnection inflows are symmetric, and consistent with fast reconnection, and the post-reconnection loops show a clear cooling and deceleration as they retract. Observations of coronal reconnection flows are still rare, and most events are observed at the solar limb, obscured by complex foregrounds, making their relationship to the flare ribbons, cusp field, and arcades formed in the lower atmosphere difficult to interpret. The disk location and favorable perspective of this event have removed these ambiguities giving a clear picture of the reconnection dynamics.

  6. The comparison of SRs' variation affected by solar events observed in America and in China

    Science.gov (United States)

    Yu, H.; Williams, E.

    2017-12-01

    Schumann Resonances(SRs) are the electromagnetic resonance wave propagating in the earth-ionosphere cavity. Its characteristic of propagation are modified by the variation of ionosphere. So SRs can be the tools of monitoring the ionosphere which is often perturbed by solar events, x-ray emission and some other space-weather events (Roldugin et.al., 2004, De et al., 2010; Satori et.al., 2015). In present work, the amplitude and intrinsic frequencies of SRs observed at RID station in America and YSH station in China are compared. The variation of SRs during the solar flare on Feb. 15, 2011 are analyzed. Two-Dimensional Telegraph Equation(TDTE) method is used to simulate the perturbation of ionosphere by solar proton events. From the simulation and observation, the asymmetric construction of ionoshphere which is perturbed by the solar event will affect the amplitudes and frequencies of SRs. Due to the interfere influence of forward and backward propagation of electromagnetic field, the SR amplitude on different station will present different variation. The distance among the lightning source, observer and perturbed area will produce the different variation of amplitude and frequency for different station' SR.

  7. Analysis of selected microflares observed by SphinX over the last minimum of solar activity

    Science.gov (United States)

    Siarkowski, Marek; Sylwester, Janusz; Sylwester, Barbara; Gryciuk, Magdalena

    The Solar Photometer in X-rays (SphinX) was designed to observe soft X-ray solar emission in the energy range between 1 keV and 15 keV with the resolution better than 0.5 keV. The instrument operated from February until November 2009 aboard CORONAS-Photon satellite, during the phase of exceptionally low minimum of solar activity. Here we use SphinX data for analysis of selected microflare-class events. We selected events of unusual lightcurves or location. Our study involves determination of temporal characteristics (times of start, maximum and end of flares) and analysis of physical conditions in flaring plasma (temperature, emission measure). Dedicated method has been used in order to remove emission not related to flare. Supplementary information about morphology and evolution of investigated events has been derived from the analysis of XRT/Hinode and SECCHI /STEREO images.

  8. Observation of solar HLy-α by K-9M-59 rocket

    International Nuclear Information System (INIS)

    Watanabe, Norihiko; Tono, Ichiro; Koshio, Takafumi.

    1978-01-01

    The purpose of the observation is to measure the illumination intensity of solar HLy-α (1216 A) and the altitude distribution of O 2 density in earth atmosphere. Since solar HLy-α is strongly absorbed by O 2 in the earth atmosphere, the extinction of HLy-α depends on the altitude distribution of O 2 density. The K-9M-59 rocket was launched on September 3, 1977. The HLy-α detector was a narrow-band ion chamber filled with NO gas. The result showed that the solar HLy-α irradiance at the rocket altitude of 90 km was 3.5 x 10 11 photons/cm 2 s and the altitude distribution of O 2 density was obtained. (Yoshimori, M.)

  9. Observations of magnetic pumping in the solar wind using MMS data

    Science.gov (United States)

    Lichko, Emily; Egedal, Jan; Daughton, William; Kasper, Justin

    2017-10-01

    The turbulent cascade is believed to play an important role in the energization of the solar wind plasma. However, there are characteristics of the solar wind that are not readily explained by the cascade, such as the power-law distribution of the solar wind speed. Starting from the drift kinetic equation, we have derived a magnetic pumping model, similar to the magnetic pumping well-known in fusion research, that provides an explanation for these features. In this model, particles are heated by the largest scale turbulent fluctuations, providing a complementary heating mechanism to the turbulent cascade. We will present observations of this mechanism in the bow shock region using data from the Magnetospheric MultiScale mission. This research was conducted with support from National Defense Science and Engineering Graduate (NDSEG) Fellowship, 32 CFR 168, as well as from NSF Award 1404166 and NASA award NNX15AJ73G.

  10. A Compressed Sensing-based Image Reconstruction Algorithm for Solar Flare X-Ray Observations

    Energy Technology Data Exchange (ETDEWEB)

    Felix, Simon; Bolzern, Roman; Battaglia, Marina, E-mail: simon.felix@fhnw.ch, E-mail: roman.bolzern@fhnw.ch, E-mail: marina.battaglia@fhnw.ch [University of Applied Sciences and Arts Northwestern Switzerland FHNW, 5210 Windisch (Switzerland)

    2017-11-01

    One way of imaging X-ray emission from solar flares is to measure Fourier components of the spatial X-ray source distribution. We present a new compressed sensing-based algorithm named VIS-CS, which reconstructs the spatial distribution from such Fourier components. We demonstrate the application of the algorithm on synthetic and observed solar flare X-ray data from the Reuven Ramaty High Energy Solar Spectroscopic Imager satellite and compare its performance with existing algorithms. VIS-CS produces competitive results with accurate photometry and morphology, without requiring any algorithm- and X-ray-source-specific parameter tuning. Its robustness and performance make this algorithm ideally suited for the generation of quicklook images or large image cubes without user intervention, such as for imaging spectroscopy analysis.

  11. A Compressed Sensing-based Image Reconstruction Algorithm for Solar Flare X-Ray Observations

    Science.gov (United States)

    Felix, Simon; Bolzern, Roman; Battaglia, Marina

    2017-11-01

    One way of imaging X-ray emission from solar flares is to measure Fourier components of the spatial X-ray source distribution. We present a new compressed sensing-based algorithm named VIS_CS, which reconstructs the spatial distribution from such Fourier components. We demonstrate the application of the algorithm on synthetic and observed solar flare X-ray data from the Reuven Ramaty High Energy Solar Spectroscopic Imager satellite and compare its performance with existing algorithms. VIS_CS produces competitive results with accurate photometry and morphology, without requiring any algorithm- and X-ray-source-specific parameter tuning. Its robustness and performance make this algorithm ideally suited for the generation of quicklook images or large image cubes without user intervention, such as for imaging spectroscopy analysis.

  12. IUE observations of solar-type stars in the Pleiades and the Hyades

    Science.gov (United States)

    Caillault, Jean-Pierre; Vilhu, Osmi; Linsky, Jeffrey L.

    1991-01-01

    An extensive set of IUE observations of solar-type stars (spectral types F5-G5) in the Pleiades is presented. Spectra were obtained in January and August 1988 for both the transition region and chromospheric emission wavelength regions, respectively. Mg II fluxes were detected for two out of three Pleiades stars and C IV upper limits for two of these stars. Long-wavelength high-resolution spectra were also obtained for previously unobserved solar-type stars in the Hyades. With the inclusion of spectra of additional Hyades stars obtained from the IUE archives, surface fluxes and fractional luminosities for both clusters' solar-type stars are calculated; these values provide a better estimate for the Mg II saturation line for single stars.

  13. Solar Wind Deflection by Mass Loading in the Martian Magnetosheath Based on MAVEN Observations

    Science.gov (United States)

    Dubinin, E.; Fraenz, M.; Pätzold, M.; Halekas, J. S.; Mcfadden, J.; Connerney, J. E. P.; Jakosky, B. M.; Vaisberg, O.; Zelenyi, L.

    2018-03-01

    Mars Atmosphere and Volatile EvolutioN observations at Mars show clear signatures of the shocked solar wind interaction with the extended oxygen atmosphere and hot corona displayed in a lateral deflection of the magnetosheath flow in the direction opposite to the direction of the solar wind motional electric field. The value of the velocity deflection reaches ˜50 km/s. The occurrence of such deflection is caused by the "Lorentz-type" force due to a differential streaming of the solar wind protons and oxygen ions originating from the extended oxygen corona. The value of the total deceleration of the magnetosheath flow due to mass loading is estimated as ˜40 km/s.

  14. EIT: Solar corona synoptic observations from SOHO with an Extreme-ultraviolet Imaging Telescope

    Science.gov (United States)

    Delaboudiniere, J. P.; Gabriel, A. H.; Artzner, G. E.; Michels, D. J.; Dere, K. P.; Howard, R. A.; Catura, R.; Stern, R.; Lemen, J.; Neupert, W.

    1988-01-01

    The Extreme-ultraviolet Imaging Telescope (EIT) of SOHO (solar and heliospheric observatory) will provide full disk images in emission lines formed at temperatures that map solar structures ranging from the chromospheric network to the hot magnetically confined plasma in the corona. Images in four narrow bandpasses will be obtained using normal incidence multilayered optics deposited on quadrants of a Ritchey-Chretien telescope. The EIT is capable of providing a uniform one arc second resolution over its entire 50 by 50 arc min field of view. Data from the EIT will be extremely valuable for identifying and interpreting the spatial and temperature fine structures of the solar atmosphere. Temporal analysis will provide information on the stability of these structures and identify dynamical processes. EIT images, issued daily, will provide the global corona context for aid in unifying the investigations and in forming the observing plans for SOHO coronal instruments.

  15. NuSTAR Hard X-Ray Observation of a Sub-A Class Solar Flare

    Energy Technology Data Exchange (ETDEWEB)

    Glesener, Lindsay [School of Physics and Astronomy, University of Minnesota, Minneapolis (United States); Krucker, Säm; Hudson, Hugh [Space Sciences Laboratory, University of California at Berkeley, Berkeley (United States); Hannah, Iain G. [SUPA School of Physics and Astronomy, University of Glasgow, Glasgow (United Kingdom); Grefenstette, Brian W. [Cahill Center for Astrophysics, California Institute of Technology, Pasadena (United States); White, Stephen M. [Air Force Research Laboratory, Albuquerque (United States); Smith, David M.; Marsh, Andrew J. [Santa Cruz Institute of Particle Physics and Department of Physics, University of California at Santa Cruz, Santa Cruz (United States)

    2017-08-20

    We report a Nuclear Spectroscopic Telescope Array ( NuSTAR ) observation of a solar microflare, SOL2015-09-01T04. Although it was too faint to be observed by the GOES X-ray Sensor, we estimate the event to be an A0.1 class flare in brightness. This microflare, with only ∼5 counts s{sup −1} detector{sup −1} observed by the Reuven Ramaty High Energy Solar Spectroscopic Imager ( RHESSI ), is fainter than any hard X-ray (HXR) flare in the existing literature. The microflare occurred during a solar pointing by the highly sensitive NuSTAR astrophysical observatory, which used its direct focusing optics to produce detailed HXR microflare spectra and images. The microflare exhibits HXR properties commonly observed in larger flares, including a fast rise and more gradual decay, earlier peak time with higher energy, spatial dimensions similar to the RHESSI microflares, and a high-energy excess beyond an isothermal spectral component during the impulsive phase. The microflare is small in emission measure, temperature, and energy, though not in physical size; observations are consistent with an origin via the interaction of at least two magnetic loops. We estimate the increase in thermal energy at the time of the microflare to be 2.4 × 10{sup 27} erg. The observation suggests that flares do indeed scale down to extremely small energies and retain what we customarily think of as “flare-like” properties.

  16. A MODEL OF MAGNETIC BRAKING OF SOLAR ROTATION THAT SATISFIES OBSERVATIONAL CONSTRAINTS

    International Nuclear Information System (INIS)

    Denissenkov, Pavel A.

    2010-01-01

    The model of magnetic braking of solar rotation considered by Charbonneau and MacGregor has been modified so that it is able to reproduce for the first time the rotational evolution of both the fastest and slowest rotators among solar-type stars in open clusters of different ages, without coming into conflict with other observational constraints, such as the time evolution of the atmospheric Li abundance in solar twins and the thinness of the solar tachocline. This new model assumes that rotation-driven turbulent diffusion, which is thought to amplify the viscosity and magnetic diffusivity in stellar radiative zones, is strongly anisotropic with the horizontal components of the transport coefficients strongly dominating over those in the vertical direction. Also taken into account is the poloidal field decay that helps to confine the width of the tachocline at the solar age. The model's properties are investigated by numerically solving the azimuthal components of the coupled momentum and magnetic induction equations in two dimensions using a finite element method.

  17. Activity associated with coronal mass ejections at solar minimum - SMM observations from 1984-1986

    Science.gov (United States)

    St. Cyr, O. C.; Webb, D. F.

    1991-01-01

    Seventy-three coronal mass ejections (CMEs) observed by the coronagraph aboard SMM between 1984 and 1986 were examined in order to determine the distribution of various forms of solar activity that were spatially and temporally associated with mass ejections during solar minimum phase. For each coronal mass ejection a speed was measured, and the departure time of the transient from the lower corona estimated. Other forms of solar activity that appeared within 45 deg longitude and 30 deg latitude of the mass ejection and within +/-90 min of its extrapolated departure time were explored. The statistical results of the analysis of these 73 CMEs are presented, and it is found that slightly less than half of them were infrequently associated with other forms of solar activity. It is suggested that the distribution of the various forms of activity related to CMEs does not change at different phases of the solar cycle. For those CMEs with associations, it is found that eruptive prominences and soft X-rays were the most likely forms of activity to accompany the appearance of mass ejections.

  18. Estimation of daily solar radiation from routinely observed meteorological data in Chongqing, China

    International Nuclear Information System (INIS)

    Li Maofen; Liu Hongbin; Guo Pengtao; Wu Wei

    2010-01-01

    Solar radiation is a very important and major variable in crop simulation models. However, it is measured at a very limited number of meteorological stations worldwide. Models were developed to estimate daily solar radiation in Chongqing, one of the most important agricultural areas in China. Several routinely observed meteorological variables including daily maximum and minimum temperatures, daily mean dew point temperature, fog and rainfall had been obtained, investigated and analyzed from 1986 to 2000 for Chongqing. The monthly mean daily solar radiation at this location ranged from a maximum of 15.082 MJ m -2 day -1 in August and a minimum of 3.042 MJ m -2 day -1 in December. A newly developed model that included all selected variables proved the best method with a RMSE value of 2.522 MJ m -2 day -1 . The best performed models for different seasons were further evaluated according to divide-and-conquer principle. The model using all selected variables provided the best estimates of daily solar radiation in winter and autumn with RMSE values of 1.491 and 2.037 MJ m -2 day -1 , respectively. The method involving temperatures and rainfall information could be used to estimate daily solar radiation in summer with a RMSE value of 3.163 MJ m -2 day -1 . The model using temperature, rainfall and dew point data performed better than other models in spring with a RMSE value of 2.910 MJ m -2 day -1 .

  19. Observation of the Kelvin–Helmholtz Instability in a Solar Prominence

    Science.gov (United States)

    Yang, Heesu; Xu, Zhi; Lim, Eun-Kyung; Kim, Sujin; Cho, Kyung-Suk; Kim, Yeon-Han; Chae, Jongchul; Cho, Kyuhyoun; Ji, Kaifan

    2018-04-01

    Many solar prominences end their lives in eruptions or abrupt disappearances that are associated with dynamical or thermal instabilities. Such instabilities are important because they may be responsible for energy transport and conversion. We present a clear observation of a streaming kink-mode Kelvin–Helmholtz Instability (KHI) taking place in a solar prominence using the Hα Lyot filter installed at the New Vacuum Solar Telescope, Fuxian-lake Solar Observatory in Yunnan, China. On one side of the prominence, a series of plasma blobs floated up from the chromosphere and streamed parallel to the limb. The plasma stream was accelerated to about 20–60 km s‑1 and then undulated. We found that 2″- and 5″-size vortices formed, floated along the stream, and then broke up. After the 5″-size vortex, a plasma ejection out of the stream was detected in the Solar Dynamics Observatory/Atmospheric Imaging Assembly images. Just before the formation of the 5″-size vortex, the stream displayed an oscillatory transverse motion with a period of 255 s with the amplitude growing at the rate of 0.001 s‑1. We attribute this oscillation of the stream and the subsequent formation of the vortex to the KHI triggered by velocity shear between the stream, guided by the magnetic field and the surrounding media. The plasma ejection suggests the transport of prominence material into the upper layer by the KHI in its nonlinear stage.

  20. DETECTION OF VORTEX TUBES IN SOLAR GRANULATION FROM OBSERVATIONS WITH SUNRISE

    International Nuclear Information System (INIS)

    Steiner, O.; Franz, M.; Bello Gonzalez, N.; Nutto, Ch.; Rezaei, R.; Schmidt, W.; Martinez Pillet, V.; Bonet Navarro, J. A.; Del Toro Iniesta, J. C.; Domingo, V.; Solanki, S. K.; Barthol, P.; Gandorfer, A.; Knoelker, M.

    2010-01-01

    We have investigated a time series of continuum intensity maps and corresponding Dopplergrams of granulation in a very quiet solar region at the disk center, recorded with the Imaging Magnetograph eXperiment (IMaX) on board the balloon-borne solar observatory SUNRISE. We find that granules frequently show substructure in the form of lanes composed of a leading bright rim and a trailing dark edge, which move together from the boundary of a granule into the granule itself. We find strikingly similar events in synthesized intensity maps from an ab initio numerical simulation of solar surface convection. From cross sections through the computational domain of the simulation, we conclude that these granular lanes are the visible signature of (horizontally oriented) vortex tubes. The characteristic optical appearance of vortex tubes at the solar surface is explained. We propose that the observed vortex tubes may represent only the large-scale end of a hierarchy of vortex tubes existing near the solar surface.

  1. Design and modeling of an SJ infrared solar cell approaching upper limit of theoretical efficiency

    Science.gov (United States)

    Sahoo, G. S.; Mishra, G. P.

    2018-01-01

    Recent trends of photovoltaics account for the conversion efficiency limit making them more cost effective. To achieve this we have to leave the golden era of silicon cell and make a path towards III-V compound semiconductor groups to take advantages like bandgap engineering by alloying these compounds. In this work we have used a low bandgap GaSb material and designed a single junction (SJ) cell with a conversion efficiency of 32.98%. SILVACO ATLAS TCAD simulator has been used to simulate the proposed model using both Ray Tracing and Transfer Matrix Method (under 1 sun and 1000 sun of AM1.5G spectrum). A detailed analyses of photogeneration rate, spectral response, potential developed, external quantum efficiency (EQE), internal quantum efficiency (IQE), short-circuit current density (JSC), open-circuit voltage (VOC), fill factor (FF) and conversion efficiency (η) are discussed. The obtained results are compared with previously reported SJ solar cell reports.

  2. Evidence for explosive chromospheric evaporation in a solar flare observed with SMM

    Science.gov (United States)

    Zarro, D. M.; Saba, J. L. R.; Strong, K. T.; Canfield, R. C.; Metcalf, T.

    1986-01-01

    SMM soft X-ray data and Sacramento Peak Observatory H-alpha observations are combined in a study of the impulsive phase of a solar flare. A blue asymmetry, indicative of upflow motions, was observed in the coronal Ca XIX line during the soft X-ray rise phase. H-alpha redshifts, indicative of downward motions, were observed simultaneously in bright flare kernels during the period of hard X-ray emission. It is shown that, to within observational errors, the impulsive phase momentum transported by the upflowing soft X-ray plasma is equivalent to that of the downward moving chromospheric material.

  3. Detection of organic compound signatures in infra-red, limb emission spectra observed by the MIPAS-B2 balloon instrument

    Directory of Open Access Journals (Sweden)

    J. J. Remedios

    2007-01-01

    Full Text Available Organic compounds play a central role in troposphere chemistry and increasingly are a viable target for remote sensing observations. In this paper, infra-red spectral features of three organic compounds are investigated in thermal emission spectra recorded on a flight on 8 May 1998 near Aire sur l'Adour by a balloon-borne instrument, MIPAS-B2, operating at high spectral resolution. It is demonstrated, for the first time, that PAN and acetone can be detected in infra-red remote sensing spectra of the upper troposphere; detection results are presented at tangent altitudes of 10.4 km and 7.5 km (not acetone. In addition, the results provide the first observation of spectral features of formic acid in thermal emission, as opposed to solar occultation, and confirm that concentrations of this gas are measurable in the mid-latitude upper troposphere, given accurate spectroscopic data. For PAN, two bands are observed centred at 794 cm−1 and 1163 cm−1. For acetone and formic acid, one band has been detected for each so far with band centres at 1218 cm−1 and 1105 cm−1 respectively. Mixing ratios inferred at 10.4 km tangent altitude are 180 pptv and 530 pptv for PAN and acetone respectively, and 200 pptv for formic acid with HITRAN 2000 spectroscopy. Accuracies are on the order of 15 to 40%. The detection technique applied here is verified by examining weak but known signatures of CFC-12 and HCFC-22 in the same spectral regions as those of the organic compounds, with results confirming the quality of both the instrument and the radiative transfer model. The results suggest the possibility of global sensing of the organic compounds studied here which would be a major step forward in verifying and interpreting global tropospheric model calculations.

  4. Infrared Spectroscopic Observations on the Fate of Organophosphorus Compounds Exposed to Atmospheric Moisture. Part 3

    Science.gov (United States)

    2007-05-01

    FATE OF ORGANOPHOSPHORUS COMPOUNDS EXPOSED TO ATMOSPHERIC MOISTURE PART III. PHOSPHINES, PHOSPHITES , PHOSPHONITES, PHOSPHINITES, PHOSPHORIC ACIDS ...The investigation continues with Phosphines, Phosphites , Phosphonites, Phosphinites, Phosphoric Acids , Phosphonic Acids , Phosphinic Acids , Phosphine...infrared spectrum of di-(2-ethylhexyl) phosphoric acid as a liquid film between KBr windows is given in Figure 104. The band assignments are as follows

  5. Observations of the Hubble Deep Field with the Infrared Space Observatory .2. Source detection and photometry

    DEFF Research Database (Denmark)

    Goldschmidt, P.; Oliver, S.J.; Serjeant, S.B.G.

    1997-01-01

    We present positions and fluxes of point sources found in the Infrared Space Observatory (ISO) images of the Hubble Deep Field (HDF) at 6.7 and 15 mu m. We have constructed algorithmically selected 'complete' flux-limited samples of 19 sources in the 15-mu m image, and seven sources in the 6.7-mu m...

  6. Deep far infrared ISOPHOT survey in "Selected Area 57" - I. Observations and source counts

    DEFF Research Database (Denmark)

    Linden-Vornle, M.J.D.; Nørgaard-Nielsen, Hans Ulrik; Jørgensen, H.E.

    2000-01-01

    We present here the results of a deep survey in a 0.4 deg(2) blank field in Selected Area 57 conducted with the ISOPHOT instrument aboard ESAs Infrared Space Observatory (ISO1) at both 60 mu m and 90 mu m. The resulting sky maps have a spatial resolution of 15 x 23 arcsrc(2) per pixel which is much...

  7. Keck observations of near-Earth asteroids in the thermal infrared

    Czech Academy of Sciences Publication Activity Database

    Delbó, M.; Harris, A. W.; Binzel, R. P.; Pravec, Petr; Davies, J. K.

    2003-01-01

    Roč. 166, č. 1 (2003), s. 116-130 ISSN 0019-1035 R&D Projects: GA AV ČR IAA3003204; GA ČR GA205/99/0255 Institutional research plan: CEZ:AV0Z1003909 Keywords : asteroids * infrared observtions * photometry Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 2.611, year: 2003

  8. Radio and infrared observations of (almost) one hundred non-Seyfert Markarian galaxies

    Science.gov (United States)

    Dressel, Linda L.

    1987-01-01

    The 13 cm flux densities of 96 non-Seyfert Markarian galaxies were measured at Arecibo Observatory. Far infrared flux densities have been published for 78 of these galaxies in the IRAS catalog. The radio, infrared, and optical fluxes of these galaxies and of a magnitude limited sample of normal galaxies were compared to clarify the nature of the radio emission in Markarian galaxies. It was found that Markarian galaxies of a given apparent magnitude and Hubble type generally have radio fluxes several times higher that the fluxes typical of normal galaxies of the same magnitude and type. Remarkably, the ratio of radio flux to far infrared flux is nearly the same for most of these starburst galaxies and for normal spiral disks. However, the compact and peculiar Markarian galaxies consistently have about 60% more radio flux per unit infrared flux than the other Markarian galaxies and the normal spirals. It is not clear whether this difference reflects a difference in the evolution of the starbursts in these galaxies or whether there is excess radio emission of nonstellar origin.

  9. ISO far-infrared observations of rich galaxy clusters II. Sersic 159-03

    DEFF Research Database (Denmark)

    Hansen, Lene; Jørgensen, H.E.; Nørgaard-Nielsen, Hans Ulrik

    2000-01-01

    In a series of papers we investigate far-infrared emission from rich galaxy clusters. Maps have been obtained by ISO at 60 mu m, 100 mu m, 135 mu m, and 200 mu m using the PHT-C camera. Ground based imaging and spectroscopy were also acquired. Here we present the results for the cooling flow...

  10. Dust impact on surface solar irradiance assessed with model simulations, satellite observations and ground-based measurements

    Directory of Open Access Journals (Sweden)

    P. G. Kosmopoulos

    2017-07-01

    Full Text Available This study assesses the impact of dust on surface solar radiation focussing on an extreme dust event. For this purpose, we exploited the synergy of AERONET measurements and passive and active satellite remote sensing (MODIS and CALIPSO observations, in conjunction with radiative transfer model (RTM and chemical transport model (CTM simulations and the 1-day forecasts from the Copernicus Atmosphere Monitoring Service (CAMS. The area of interest is the eastern Mediterranean where anomalously high aerosol loads were recorded between 30 January and 3 February 2015. The intensity of the event was extremely high, with aerosol optical depth (AOD reaching 3.5, and optical/microphysical properties suggesting aged dust. RTM and CTM simulations were able to quantify the extent of dust impact on surface irradiances and reveal substantial reduction in solar energy exploitation capacity of PV and CSP installations under this high aerosol load. We found that such an extreme dust event can result in Global Horizontal Irradiance (GHI attenuation by as much as 40–50 % and a much stronger Direct Normal Irradiance (DNI decrease (80–90 %, while spectrally this attenuation is distributed to 37 % in the UV region, 33 % in the visible and around 30 % in the infrared. CAMS forecasts provided a reliable available energy assessment (accuracy within 10 % of that obtained from MODIS. Spatially, the dust plume resulted in a zonally averaged reduction of GHI and DNI of the order of 150 W m−2 in southern Greece, and a mean increase of 20 W m−2 in the northern Greece as a result of lower AOD values combined with local atmospheric processes. This analysis of a real-world scenario contributes to the understanding and quantification of the impact range of high aerosol loads on solar energy and the potential for forecasting power generation failures at sunshine-privileged locations where solar power plants exist, are under construction or are

  11. Late-time Near-infrared Observations of SN 2005df

    Science.gov (United States)

    Diamond, Tiara R.; Hoeflich, Peter; Gerardy, Christopher L.

    2015-06-01

    We present late-time near-infrared (NIR) spectral evolution, at 200-400 days, for the Type Ia supernova SN 2005df. The spectra show numerous strong emission features of [Co ii], [Co iii], and [Fe ii] throughout the 0.8-1.8 μm region. As the spectrum ages, the cobalt features fade as would be expected from the decay of 56Co to 56Fe. We show that the strong and isolated [Fe ii] emission line at 1.644 μ {m} provides a unique tool to analyze NIR spectra of SNe Ia. Normalization of spectra to this line allows the separation of features produced by stable versus unstable isotopes of iron group elements. We develop a new method of determining the initial central density, {ρ }c, and the magnetic field, B, of the white dwarf (WD) using the width of the 1.644 μ {m} line. The line width (LW) is sensitive because of electron capture in the early stages of burning, which increases as a function of density. The sensitivity of the LW to B increases with time, and the effects of the magnetic field shift toward later times with decreasing {ρ }c. Through comparison with spherical models, the initial central density for SN 2005df is measured as {ρ }c=0.9(+/- 0.2)× {10}9 {g} {{cm}}-3, which corresponds to a WD close to the Chandrasekhar mass, with {M}{WD}=1.31(+/- 0.03) {M}⊙ and systematic error less than 0.04 {M}⊙. This error estimate is based on spherical models. We discuss the potential uncertainties due to multi-dimensional effects, mixing, and rotation. The latter two effects would increase the estimate of the WD mass. Within {M}{Ch} explosions, however, the central density found for SN 2005df is very low for a H-accretor, possibly suggesting a helium star companion or a tidally disrupted WD companion. As an alternative, we suggest mixing of the central region. We find some support for high initial magnetic fields of strength {10}6 {G} for SN 2005df, however, 0 {G} cannot be ruled out because of noise in the spectra combined with low {ρ }c. We discuss our findings in

  12. VERY LARGE ARRAY OBSERVATIONS OF THE INFRARED DARK CLOUD G19.30+0.07

    International Nuclear Information System (INIS)

    Devine, K. E.; Churchwell, E.; Chandler, C. J.; Borg, K. J.; Brogan, C.; Indebetouw, R.; Shirley, Y.

    2011-01-01

    We present Very Large Array observations of ammonia (NH 3 ) (1,1), (2,2), and dicarbon sulfide (CCS) (2 1 -1 0 ) emission toward the infrared dark cloud (IRDC) G19.30+0.07 at ∼22 GHz. The NH 3 emission closely follows the 8 μm extinction. The NH 3 (1,1) and (2,2) lines provide diagnostics of the temperature and density structure within the IRDC, with typical rotation temperatures of ∼10-20 K and NH 3 column densities of ∼10 15 cm -2 . The estimated total mass of G19.30+0.07 is ∼1130 M sun . The cloud comprises four compact NH 3 clumps of mass ∼30-160 M sun . Two coincide with 24 μm emission, indicating heating by protostars, and show evidence of outflow in the NH 3 emission. We report a water maser associated with a third clump; the fourth clump is apparently starless. A non-detection of 8.4 GHz emission suggests that the IRDC contains no bright H II regions and places a limit on the spectral type of an embedded zero-age main-sequence star to early-B or later. From the NH 3 emission, we find that G19.30+0.07 is composed of three distinct velocity components or 'subclouds'. One velocity component contains the two 24 μm sources and the starless clump, another contains the clump with the water maser, while the third velocity component is diffuse, with no significant high-density peaks. The spatial distribution of NH 3 and CCS emission from G19.30+0.07 is highly anti-correlated, with the NH 3 predominantly in the high-density clumps and the CCS tracing lower-density envelopes around those clumps. This spatial distribution is consistent with theories of evolution for chemically young low-mass cores, in which CCS has not yet been processed to other species and/or depleted in high-density regions.

  13. Observation of solar radio bursts using swept-frequency radiospectrograph in 20 - 40 MHz band

    International Nuclear Information System (INIS)

    Aoyama, Takashi; Oya, Hiroshi.

    1987-01-01

    A new station for the observation of solar decametric radio bursts has been developed at Miyagi Vocational Training College in Tsukidate, Miyagi, Japan. Using the swept frequency radiospectrograph covering a frequency range from 20 MHz to 40 MHz within 200 msec, with bandwidth of 30 kHz, the radio outbursts from the sun have been currently monitored with colored dynamic spectrum display. After July 1982, successful observations provide the data which include all types of solar radio bursts such as type I, II, III, IV and V in the decametric wavelength range. In addition to these typical radio bursts, rising tone bursts with fast drift rate followed by strong type III bursts and a series of bursts repeating rising and falling tone bursts with slow drift rate have been observed. (author)

  14. Study and use of an infrared camera optimized for ground based observations in the 10 micron wavelength range

    International Nuclear Information System (INIS)

    Remy, Sophie

    1991-01-01

    Astronomical observations in the 10 micron atmospheric window provide very important information for many of astrophysical topics. But because of the very large terrestrial photon background at that wavelength, ground based observations have been impeded. On the other band, the ground based telescopes offer a greater angular resolution than the spatially based telescopes. The recent development of detector arrays for the mid infrared range made easier the development of infrared cameras with optimized detectors for astronomical observations from the ground. The CAMIRAS infrared camera, built by the 'Service d'Astrophysique' in Saclay is the instrument we have studied and we present its performances. Its sensitivity, given for an integration time of one minute on source and a signal to noise ratio of 3, is 0.15 Jy for punctual sources, and 20 mJy arcs"-"2 for extended sources. But we need to get rid of the enormous photon background so we have to find a better way of observation based on modulation techniques as 'chopping' or 'nodding'. Thus we show that a modulation about 1 Hz is satisfactory with our detectors arrays without perturbing the signal to noise ratio. As we have a good instrument and because we are able to get rid of the photon background, we can study astronomical objects. Results from a comet, dusty stellar disks, and an ultra-luminous galaxy are presented. (author) [fr

  15. Clouds across the Arctic: A spatial perspective uniting surface observations of downwelling infrared radiation, reanalyses and education

    Science.gov (United States)

    Cox, Christopher J.

    The polar regions serve an important role in the Earth's energy balance by acting as a heat sink for the global climate system. In the Arctic, a complex distribution of continental and oceanic features support large spatial variability in environmental parameters important for climate. Additionally, feedbacks that are unique to the cryosphere cause the region to be very sensitive to climate perturbations. Environmental changes are being observed, including increasing temperatures, reductions in sea ice extent and thickness, melting permafrost, changing atmospheric circulation patterns and changing cloud properties, which may be signaling a shift in climate. Despite these changes, the Arctic remains an understudied region, including with respect to the atmosphere and clouds. A better understanding of cloud properties and their geographical variability is needed to better understand observed changes and to forecast the future state of the system, to support adaptation and mitigation strategies, and understand how Arctic change impacts other regions of the globe. Surface-based observations of the atmosphere are critical measurements in this effort because they are high quality and have high temporal resolution, but there are few atmospheric observatories in the Arctic and the period of record is short. Reanalyses combine assimilated observations with models to fill in spatial and temporal data gaps, and also provide additional model-derived parameters. Reanalyses are spatially comprehensive, but are limited by large uncertainties and biases, in particular with respect to derived parameters. Infrared radiation is a large component of the surface energy budget. Infrared emission from clouds is closely tied to cloud properties, so measurements of the infrared spectrum can be used to retrieve information about clouds and can also be used to investigate the influence clouds have on the surface radiation balance. In this dissertation, spectral infrared radiances and other

  16. Observations and Interpretations of Energetic Neutral Hydrogen Atoms from the December 5, 2006 Solar Event

    Science.gov (United States)

    Mewaldt, R. A.; Leske, R. A.; Shih, A. Y.; Stone, E. C.; Barghouty, A. f.; Cohen, C. M. S.; Cummings, A. c.; Labrador, A. W.; vonRosenvinge, T. T.

    2009-01-01

    We discuss recently reported observations of energetic neutral hydrogen atoms (ENAs) from an X9 solar flare/coronal mass ejection event on 5 December 2006, located at E79. The observations were made by the Low Energy Telescopes (LETs) on STEREO A and B. Prior to the arrival of the main solar energetic particle (SEP) event at Earth, both LETs observed a sudden burst of 1.6 to 15 MeV energetic neutral hydrogen atoms produced by either flare or shock-accelerated protons. RHESSI measurements of the 2.2-MeV gamma-ray line provide an estimate of the number of interacting flare-accelerated protons in this event, which leads to an improved estimate of ENA production by flare-accelerated protons. Taking into account ENA losses, we find that the observed ENAs must have been produced in the high corona at heliocentric distances > or equal to 2 solar radii. Although there are no CME images from this event, it is shown that CME-shock-accelerated protons can, in principle, produce a time-history consistent with the observations.

  17. Solar Energetic Particle Composition over Two Solar Cycles as Observed by the Ulysses/HISCALE and ACE/EPAM Pulse Height Analyzers.

    Science.gov (United States)

    Patterson, J. D.; Madanian, H.; Manweiler, J. W.; Lanzerotti, L. J.

    2017-12-01

    We present the compositional variation in the Solar Energetic Particle (SEP) population in the inner heliosphere over two solar cycles using data from the Ulysses Heliospheric Instrument for Spectra, Composition, and Anisotropy at Low Energies (HISCALE) and Advanced Composition Explorer (ACE) Electron Proton Alpha Monitor (EPAM). The Ulysses mission was active from late 1990 to mid-2009 in a heliopolar orbit inclined by 80° with a perihelion of 1.3 AU and an aphelion of 5.4 AU. The ACE mission has been active since its launch in late 1997 and is in a halo orbit about L1. These two missions provide a total of 27 years of continuous observation in the inner heliosphere with twelve years of simultaneous observation. HISCALE and EPAM data provide species-resolved differential flux and density of SEP between 0.5-5 MeV/nuc. Several ion species (He, C, O, Ne, Si, Fe) are identified using the Pulse Height Analyzer (PHA) system of the Composition Aperture for both instruments. The He density shows a noticeable increase at high solar activity followed by a moderate drop at the quiet time of the solar minimum between cycles 23 and 24. The density of heavier ions (i.e. O and Fe) change minimally with respect to the F10.7 index variations however, certain energy-specific count rates decrease during solar minimum. With Ulysses and ACE observing in different regions of the inner heliosphere, there are significant latitudinal differences in how the O/He ratios vary with the solar cycle. At solar minimum, there is reasonable agreement between the observations from both instruments. At solar max 23, the differences in composition over the course of the solar cycle, and as observed at different heliospheric locations can provide insight to the origins of and acceleration processes differentially affecting solar energetic ions.

  18. Infrared Space Observatory Observations of Far-Infrared Rotational Emission Lines of Water Vapor toward the Supergiant Star VY Canis Majoris

    Science.gov (United States)

    Neufeld, David A.; Feuchtgruber, Helmut; Harwit, Martin; Melnick, Gary J.

    1999-06-01

    We report the detection of numerous far-infrared emission lines of water vapor toward the supergiant star VY Canis Majoris. A 29.5-45 μm grating scan of VY CMa, obtained using the Short-Wavelength Spectrometer (SWS) of the Infrared Space Observatory at a spectral resolving power λ/Δλ of ~2000, reveals at least 41 spectral features due to water vapor that together radiate a total luminosity of ~25 Lsolar. In addition to pure rotational transitions within the ground vibrational state, these features include rotational transitions within the (010) excited vibrational state. The spectrum also shows the 2Π1/2(J=5/2)VY CMa were carried out in the instrument's Fabry-Perot mode for three water transitions: the 725-616 line at 29.8367 μm, the 441-312 line at 31.7721 μm, and the 432-303 line at 40.6909 μm. The higher spectral resolving power λ/Δλ of approximately 30,000 thereby obtained permits the line profiles to be resolved spectrally for the first time and reveals the ``P Cygni'' profiles that are characteristic of emission from an outflowing envelope. Based on observations with ISO, an ESA project with instruments funded by ESA Member States (especially the PI countries: France, Germany, the Netherlands, and the UK) with the participation of ISAS and NASA.

  19. Surface Net Solar Radiation Estimated from Satellite Measurements: Comparisons with Tower Observations

    Science.gov (United States)

    Li, Zhanqing; Leighton, H. G.; Cess, Robert D.

    1993-01-01

    A parameterization that relates the reflected solar flux at the top of the atmosphere to the net solar flux at the surface in terms of only the column water vapor amount and the solar zenith angle was tested against surface observations. Net surface fluxes deduced from coincidental collocated satellite-measured radiances and from measurements from towers in Boulder during summer and near Saskatoon in winter have mean differences of about 2 W/sq m, regardless of whether the sky is clear or cloudy. Furthermore, comparisons between the net fluxes deduced from the parameterization and from surface measurements showed equally good agreement when the data were partitioned into morning and afternoon observations. This is in contrast to results from an empirical clear-sky algorithm that is unable to account adequately for the effects of clouds and that shows, at Boulder, a distinct morning to afternoon variation, which is presumably due to the predominance of different cloud types throughout the day. It is also demonstrated that the parameterization may be applied to irradiances at the top of the atmosphere that have been temporally averaged by using the temporally averaged column water vapor amount and the temporally averaged cosine of the solar zenith angle. The good agreement between the results of the parameterization and surface measurements suggests that the algorithm is a useful tool for a variety of climate studies.

  20. Spacecraft radio scattering observations of the power spectrum of electron density fluctuations in the solar wind

    International Nuclear Information System (INIS)

    Woo, R.; Armstrong, J.W.

    1979-01-01

    Solar wind electron density power spectra in the solar equatorial region are inferred from observations of phase scintillations and spectral broadening made with the Viking, Helios, and Pioneer spacecraft. The heliocentric distance range covered is 2--215 R/sub S/, and for some observations close to the sun the spectra extend to fluctuation frequencies as high as 100 Hz. For heliocentric distances > or approx. =20 R/sub S/ the equivalent spacecraft-measured one-dimensional density spectrym V/sub n/e is well modeled by a single power law (f/sup -alpha/) in the frequency range 10 -4 -5 x 10 -2 Hz. The mean spectral index α is 1.65, very close to the Kolmogorov value of 5/3. Under the assumption of constant solar wind speed, V/sub n/e varies as R/sup -3.45/, where R is heliocentric distance. Within 20 R/sub S/, V/sub n/e can still be modeled by a single power law over the frequency range 10 -3 -10 1 Hz, but the spectral index becomes smaller, αapprox.1.1. The flattening of the density spectrum with 20 R/sub S/ is presumably associated with energy deposition in the near-sun region and acceleration of the solar wind

  1. Ion acoustic waves and related plasma observations in the solar wind

    International Nuclear Information System (INIS)

    Gurnett, D.A.; Marsch, E.; Pilipp, W.; Schwenn, R.; Rosenbauer, H.

    1979-01-01

    This paper presents an investigation of solar wind ion acoustic waves and their relationship to the macroscopic and microscopic characteristics of the solar wind plasma. Comparisons with the overall solar wind corotational structure show that the most intense ion acoustic waves usually occur in the low-velocity regions ahead of high-speed solar wind streams. Of the detailed plasma parameters investigated, the ion acoustic wave intensities are found to be most closely correlated with the electron to proton temperature ratio T/sub e//T/sub p/ and with the electron heat flux. Investigations of the detailed electron and proton distribution functions also show that the ion acoustic waves usually occur in regions with highly non-Maxwellian distributions characteristic of double-proton streams. The distribution functions for the double-proton streams are usually not resolved into two clearly defined peaks, but rather they appear as a broad shoulder on the main proton distribution. Two main mechanisms, an electron heat flux instability and a double-ion beam instability, are considered for generating the ion-acoustic-like waves observed in the solar wind. Both mechanisms have favorable and unfavorable features. The electron heat flux mechanism can account for the observed waves at moderate to large ratios of T/sub e//T/sub p/ but has problems when T/sub e//T/sub p/ is small, as sometimes occurs. The ion beam instability appears to provide more flexibility on the T/sub e//T/sub p/ ratio; however detailed comparisons using observed distribution functions indicate that the ion beam mode is usually stable. Possible resolutions of these difficulties are discussed

  2. Plans to Observe the 2017 Total Solar Eclipse from near the Path Edges

    Science.gov (United States)

    Waring Dunham, David; Nugent, Richard; Guhl, Konrad; Bode, Hans-Joachim

    2015-08-01

    The August 21st, 2017 solar eclipse provides a good opportunity, to time the totality contacts, other Baily’s bead phenomena, and observe other dynamic edge phenomena, from locations near the edges of the path of totality. A good network of roads and generally favorable weather prospects means that more observers will likely be able to deploy more equipment than during most previous eclipses. The value of contact and Baily’s bead timings of total solar eclipses, for determining solar diameter and intensity variations, was described in an earlier presentation in Focus Meeting 13. This presentation will concentrate on how observations of different types that have been used during past eclipses can be made by different observers, to obtain better information about the accuracy of the different types of observations for determining the mean solar diameter, and the systematic differences between them. A problem has been that the few observers who have attempted recording Baily’s beads from path edge locations have wanted to use the latest technology, to try to record the observations better, rather than try to make the observations in the same ways that were used for many past eclipses. Several observers trying different techniques at the same location, and doing that at several locations at different places along the path, is needed. Past techniques that we would like to compare include direct visual observation (but keeping eye safety in mind); visual observation of telescopically projected images; direct filtered video telescopic observations; and recording the flash spectrum. There are several towns that straddle the path edges. The International Occultation Timing Association would like to mobilize people in those towns to observe the eclipse from many places, to say whether or not the eclipse happened, and if it did, time it. A suitable cell phone app could be designed to report observations, including the observer’s location, as was attempted for an

  3. High resolution solar observations in the context of space weather prediction

    Science.gov (United States)

    Yang, Guo

    Space weather has a great impact on the Earth and human life. It is important to study and monitor active regions on the solar surface and ultimately to predict space weather based on the Sun's activity. In this study, a system that uses the full power of speckle masking imaging by parallel processing to obtain high-spatial resolution images of the solar surface in near real-time has been developed and built. The application of this system greatly improves the ability to monitor the evolution of solar active regions and to predict the adverse effects of space weather. The data obtained by this system have also been used to study fine structures on the solar surface and their effects on the upper solar atmosphere. A solar active region has been studied using high resolution data obtained by speckle masking imaging. Evolution of a pore in an active region presented. Formation of a rudimentary penumbra is studied. The effects of the change of the magnetic fields on the upper level atmosphere is discussed. Coronal Mass Ejections (CMEs) have a great impact on space weather. To study the relationship between CMEs and filament disappearance, a list of 431 filament and prominence disappearance events has been compiled. Comparison of this list with CME data obtained by satellite has shown that most filament disappearances seem to have no corresponding CME events. Even for the limb events, only thirty percent of filament disappearances are associated with CMEs. A CME event that was observed on March 20, 2000 has been studied in detail. This event did not show the three-parts structure of typical CMEs. The kinematical and morphological properties of this event were examined.

  4. On the Importance of Solar Eclipse Geometry in the Interpretation of Ionospheric Observations

    Science.gov (United States)

    Stankov, S.; Verhulst, T. G. W.

    2017-12-01

    A reliable interpretation of solar eclipse effects on the geospace environment, and on the ionosphere in particular, necessitates a careful consideration of the so-called eclipse geometry. A solar eclipse is a relatively rare astronomical phenomenon, which geometry is rather complex, specific for each event, and fast changing in time. The standard, most popular way to look at the eclipse geometry is via the two-dimensional representation (map) of the solar obscuration on the Earth's surface, in which the path of eclipse totality is drawn together with isolines of the gradually-decreasing eclipse magnitude farther away from this path. Such "surface maps" are widely used to readily explain some of the solar eclipse effects including, for example, the well-known decrease in total ionisation (due to the substantial decrease in solar irradiation), usually presented by the popular and easy to understand ionospheric characteristic of Total Electron Content (TEC). However, many other effects, especially those taking place at higher altitudes, cannot be explained in this fashion. Instead, a complete, four-dimensional (4D) description of the umbra (and penumbra), would be required. This presentation will address the issue of eclipse geometry effects on various ionospheric observations carried out during the total solar eclipse of August 21, 2017. In particular, GPS-based TEC and ionosonde measurements will be analysed and the eclipse effects on the ionosphere will be interpreted with respect to the actual eclipse geometry at ionospheric heights. Whenever possible, a comparison will be made with results from previous events, such as the ones from March 20, 2015 and October 3, 2005.

  5. Mutual event observations of solar system objects by SRC on Mars Express. Analysis and release of observations

    Science.gov (United States)

    Ziese, R.; Willner, K.

    2018-06-01

    Context. Both Martian moons, Phobos and Deimos, have been observed during several imaging campaigns by the Super Resolution Channel (SRC) on the Mars Express probe. Several tens of images are obtained during mutual event observations - when the Martian moons are both observed or together with another solar system body. These observations provide new opportunities to determine the bodies' positions in their orbits. Aims: A method was sought to automate the observation of the positions of the imaged bodies. Within one image sequence a similarly accurate localization of the objects in all images should be possible. Methods: Shape models of Phobos and Deimos are applied to simulate the appearance of the bodies in the images. Matching the illuminated simulation against the observation provides a reliable determination of the bodies' location within the image. To enhance the matching confidence several corrections need to be applied to the simulation to closely reconstruct the observation. Results: A list of 884 relative positions between the different objects is provided through the Centre de Données astronomiques de Strasbourg (CDS). Tables A.1-A.4 are only 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/614/A15

  6. Gravity drives the evolution of infrared dark hubs: JVLA observations of SDC13

    Science.gov (United States)

    Williams, G. M.; Peretto, N.; Avison, A.; Duarte-Cabral, A.; Fuller, G. A.

    2018-05-01

    Context. Converging networks of interstellar filaments, that is hubs, have been recently linked to the formation of stellar clusters and massive stars. Understanding the relationship between the evolution of these systems and the formation of cores and stars inside them is at the heart of current star formation research. Aims: The goal is to study the kinematic and density structure of the SDC13 prototypical hub at high angular resolution to determine what drives its evolution and fragmentation. Methods: We have mapped SDC13, a 1000 M⊙ infrared dark hub, in NH3(1,1) and NH3(2,2) emission lines, with both the Jansky Very Large Array and Green Bank Telescope. The high angular resolution achieved in the combined dataset allowed us to probe scales down to 0.07 pc. After fitting the ammonia lines, we computed the integrated intensities, centroid velocities and line widths, along with gas temperatures and H2 column densities. Results: The mass-per-unit-lengths of all four hub filaments are thermally super-critical, consistent with the presence of tens of gravitationally bound cores identified along them. These cores exhibit a regular separation of 0.37 ± 0.16 pc suggesting gravitational instabilities running along these super-critical filaments are responsible for their fragmentation. The observed local increase of the dense gas velocity dispersion towards starless cores is believed to be a consequence of such fragmentation process. Using energy conservation arguments, we estimate that the gravitational to kinetic energy conversion efficiency in the SDC13 cores is 35%. We see velocity gradient peaks towards 63% of cores as expected during the early stages of filament fragmentation. Another clear observational signature is the presence of the most massive cores at the filaments' junction, where the velocity dispersion is largest. We interpret this as the result of the hub morphology generating the largest acceleration gradients near the hub centre. Conclusions: We

  7. Mid-Infrared Observations of Possible Intergalactic Star Forming Regions in the Leo Ring

    Science.gov (United States)

    Giroux, Mark; Smith, B.; Struck, C.

    2011-05-01

    Within the Leo group of galaxies lies a gigantic loop of intergalactic gas known as the Leo Ring. Not clearly associated with any particular galaxy, its origin remains uncertain. It may be a primordial intergalactic cloud alternatively, it may be a collision ring, or have a tidal origin. Combining archival Spitzer images