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Sample records for 3 solar mass

  1. Influences mass concentration of P3HT and PCBM to application of organic solar cells

    NASA Astrophysics Data System (ADS)

    Supriyanto, A.; Maya; Rosa, E. S.; Iriani, Y.; Ramelan, A. H.; Nurosyid, F.

    2016-11-01

    Poly (3-hexylthiophene) (P3HT) and [6, 6] -phenyl-C61-butyric acid methyl ester (PCBM) are used for the organic solar cell applications. P3HT and PCBM act as donors and acceptors, respectively. In this study the efficiency of the P3HT: PCBM organic solar cells as function of the mass concentration of the blend P3HT: PCBM with 1, 2, 8, 16 mg/ml. Deposition P3HT:PCBM film using spin coating with a rotary speed of 2500 rpm for 10 seconds. Optical properties of absorption spectra characteristic using a UV-Visible Spectrometer Lambda 25 and electrical properties of I-V characteristic using Keithley 2602 instrument. The results of absoption spectra for P3HT:PCBM within different mass concentration obtained 500-600 nm wavelengths. The Energy-gap obtained about 1.9eV. The organic solar cells device performance were investigated using I-V cahractyeristic. For mass concentration of 1, 2, 8 and 16 mg/ml P3HT:PCBM were obtained 0.5×10-3%, 2.2×10-3%, 5.9×10-3%, and 6.1×10-3% efficiency of organics solar cells respectively.

  2. Search for sub-eV mass solar axions by the CERN Axion Solar Telescope with 3He buffer gas.

    PubMed

    Arik, M; Aune, S; Barth, K; Belov, A; Borghi, S; Bräuninger, H; Cantatore, G; Carmona, J M; Cetin, S A; Collar, J I; Dafni, T; Davenport, M; Eleftheriadis, C; Elias, N; Ezer, C; Fanourakis, G; Ferrer-Ribas, E; Friedrich, P; Galán, J; García, J A; Gardikiotis, A; Gazis, E N; Geralis, T; Giomataris, I; Gninenko, S; Gómez, H; Gruber, E; Guthörl, T; Hartmann, R; Haug, F; Hasinoff, M D; Hoffmann, D H H; Iguaz, F J; Irastorza, I G; Jacoby, J; Jakovčić, K; Karuza, M; Königsmann, K; Kotthaus, R; Krčmar, M; Kuster, M; Lakić, B; Laurent, J M; Liolios, A; Ljubičić, A; Lozza, V; Lutz, G; Luzón, G; Morales, J; Niinikoski, T; Nordt, A; Papaevangelou, T; Pivovaroff, M J; Raffelt, G; Rashba, T; Riege, H; Rodríguez, A; Rosu, M; Ruz, J; Savvidis, I; Silva, P S; Solanki, S K; Stewart, L; Tomás, A; Tsagri, M; van Bibber, K; Vafeiadis, T; Villar, J A; Vogel, J K; Yildiz, S C; Zioutas, K

    2011-12-23

    The CERN Axion Solar Telescope (CAST) has extended its search for solar axions by using (3)He as a buffer gas. At T=1.8 K this allows for larger pressure settings and hence sensitivity to higher axion masses than our previous measurements with (4)He. With about 1 h of data taking at each of 252 different pressure settings we have scanned the axion mass range 0.39 eV≲m(a)≲0.64 eV. From the absence of excess x rays when the magnet was pointing to the Sun we set a typical upper limit on the axion-photon coupling of g(aγ)≲2.3×10(-10) GeV(-1) at 95% C.L., the exact value depending on the pressure setting. Kim-Shifman-Vainshtein-Zakharov axions are excluded at the upper end of our mass range, the first time ever for any solar axion search. In the future we will extend our search to m(a)≲1.15 eV, comfortably overlapping with cosmological hot dark matter bounds.

  3. Modeling solar wind mass-loading in the vicinity of the Sun using 3-D MHD simulations

    NASA Astrophysics Data System (ADS)

    Rasca, A. P.; Horányi, M.; Oran, R.; Holst, B.

    2014-01-01

    Collisionless shocks due to mass-loading were first discussed to describe the solar wind flow around a cometary atmosphere, showing its choking effects on the flow. Recent observations have led to an increased interest in mass-loading occurring in the solar corona due to both sungrazing comets and collisional debris production by sunward migrating interplanetary dust particles. The 1-D simulations with a hydrodynamic model have illustrated the impact on the solar wind from abrupt mass-loading in the coronal region. Full 3-D magnetohydrodynamic (MHD) simulations using a solar corona model based on the Block-Adaptive-Tree-Solarwind-Roe-Upwind-Scheme code provide a more realistic coronal environment for modeling specific events applicable to modeling the mass-loaded coronal wind. A specific application is introduced modeling the mass-loading effects from a sungrazing comet.

  4. The rapid assembly of an elliptical galaxy of 400 billion solar masses at a redshift of 2.3.

    PubMed

    Fu, Hai; Cooray, Asantha; Feruglio, C; Ivison, R J; Riechers, D A; Gurwell, M; Bussmann, R S; Harris, A I; Altieri, B; Aussel, H; Baker, A J; Bock, J; Boylan-Kolchin, M; Bridge, C; Calanog, J A; Casey, C M; Cava, A; Chapman, S C; Clements, D L; Conley, A; Cox, P; Farrah, D; Frayer, D; Hopwood, R; Jia, J; Magdis, G; Marsden, G; Martínez-Navajas, P; Negrello, M; Neri, R; Oliver, S J; Omont, A; Page, M J; Pérez-Fournon, I; Schulz, B; Scott, D; Smith, A; Vaccari, M; Valtchanov, I; Vieira, J D; Viero, M; Wang, L; Wardlow, J L; Zemcov, M

    2013-06-20

    Stellar archaeology shows that massive elliptical galaxies formed rapidly about ten billion years ago with star-formation rates of above several hundred solar masses per year. Their progenitors are probably the submillimetre bright galaxies at redshifts z greater than 2. Although the mean molecular gas mass (5 × 10(10) solar masses) of the submillimetre bright galaxies can explain the formation of typical elliptical galaxies, it is inadequate to form elliptical galaxies that already have stellar masses above 2 × 10(11) solar masses at z ≈ 2. Here we report multi-wavelength high-resolution observations of a rare merger of two massive submillimetre bright galaxies at z = 2.3. The system is seen to be forming stars at a rate of 2,000 solar masses per year. The star-formation efficiency is an order of magnitude greater than that of normal galaxies, so the gas reservoir will be exhausted and star formation will be quenched in only around 200 million years. At a projected separation of 19 kiloparsecs, the two massive starbursts are about to merge and form a passive elliptical galaxy with a stellar mass of about 4 × 10(11) solar masses. We conclude that gas-rich major galaxy mergers with intense star formation can form the most massive elliptical galaxies by z ≈ 1.5.

  5. Optimization of solar cells for air mass zero operation and a study of solar cells at high temperatures, phase 3

    NASA Technical Reports Server (NTRS)

    Blakeslee, A. E.; Hovel, H. J.; Woodall, J. M.

    1977-01-01

    The etch-back epitaxy process is described for producing thin, graded composition GaAlAs layers. The palladium-aluminum contact system is discussed along with its associated problems. Recent solar cell results under simulated air mass zero light and at elevated temperatures are reported and the growth of thin polycrystalline GaAs films on foreign substrates is developed.

  6. A comparison of solar helium-3-rich events with type II bursts and coronal mass ejections

    NASA Technical Reports Server (NTRS)

    Kahler, S.; Reames, D. V.; Sheeley, N. R., Jr.; Howard, R. A.; Michels, D. J.; Koomen, M. J.

    1985-01-01

    The acceleration process for energetic particles in He-3-rich events and for particles in normal-abundance events are compared. A list of 66 He-3-rich events observed with the Goddard Space Flight Center particle detector on ISEE 3 is presented, and it is shown that these events are not statistically associated with either of the two common signatures of normal-abundance events, metric type II and coronal mass ejections. This result indicates that enhanced abundance events may be produced only in the impulsive phases of flares, while normal abundance events are produced in subsequent flare shock waves.

  7. Fluid Aspects of Solar Wind Disturbances Driven by Coronal Mass Ejections. Appendix 3

    NASA Technical Reports Server (NTRS)

    Gosling, J. T.; Riley, Pete

    2001-01-01

    Transient disturbances in the solar wind initiated by coronal eruptions have been modeled for many years, beginning with the self-similar analytical models of Parker and Simon and Axford. The first numerical computer code (one-dimensional, gas dynamic) to study disturbance propagation in the solar wind was developed in the late 1960s, and a variety of other codes ranging from simple one-dimensional gas dynamic codes through three-dimensional gas dynamic and magnetohydrodynamic codes have been developed in subsequent years. For the most part, these codes have been applied to the problem of disturbances driven by fast CMEs propagating into a structureless solar wind. Pizzo provided an excellent summary of the level of understanding achieved from such simulation studies through about 1984, and other reviews have subsequently become available. More recently, some attention has been focused on disturbances generated by slow CMEs, on disturbances driven by CMEs having high internal pressures, and disturbance propagation effects associated with a structured ambient solar wind. Our purpose here is to provide a brief tutorial on fluid aspects of solar wind disturbances derived from numerical gas dynamic simulations. For the most part we illustrate disturbance evolution by propagating idealized perturbations, mimicking different types of CMEs, into a structureless solar wind using a simple one-dimensional, adiabatic (except at shocks), gas dynamic code. The simulations begin outside the critical point where the solar wind becomes supersonic and thus do not address questions of how the CMEs themselves are initiated. Limited to one dimension (the radial direction), the simulation code predicts too strong an interaction between newly ejected solar material and the ambient wind because it neglects azimuthal and meridional motions of the plasma that help relieve pressure stresses. Moreover, the code ignores magnetic forces and thus also underestimates the speed with which

  8. The solar cycle variation of coronal mass ejections and the solar wind mass flux

    NASA Technical Reports Server (NTRS)

    Webb, David F.; Howard, Russell A.

    1994-01-01

    Coronal mass ejections (CMEs) are an important aspect of coronal physics and a potentially significant contributor to perturbations of the solar wind, such as its mass flux. Sufficient data on CMEs are now available to permit study of their longer-term occurrency patterns. Here we present the results of a study of CME occurrence rates over more than a complete 11-year solar sunspot cycle and a comparison of these rates with those of other activity related to CMEs and with the solar wind particle flux at 1 AU. The study includes an evaluation of correlations to the CME rates, which include instrument duty cycles, visibility functions, mass detection thresholds, and geometrical considerations. The main results are as follows: (1) The frequency of occurrence of CMEs tends to track the solar activity cycle in both amplitude and phase; (2) the CME rates from different instruments, when corrected for both duty cycles and visibility functions, are reasonably consistent; (3) considering only longer-term averages, no one class of solar activity is better correlated with CME rate than any other; (4) the ratio of the annualized CME to solar wind mass flux tends to track the solar cycle; and (5) near solar maximum, CMEs can provide a significant fraction (i.e., approximately equals 15%) of the average mass flux to the near-ecliptic solar wind.

  9. Influences of mass Chlorophyll-a blends using P3HT:PCBM for efficiency of organic solar cells

    NASA Astrophysics Data System (ADS)

    Lestari, E.; Supriyanto, A.; Iriani, Y.; Ramelan, A. H.; Nurosyid, F.

    2017-02-01

    Organic solar cells have been made using the material poly (3-hexylthiophene)(P3HT), [6, 6]-phenyl-C61-butyric acid methyl ester (PCBM), and Chlorophyll-a with blend metods. Active layer of P3HT:PCBM:Chlorophyll-a are deposited using spin coating with rotary speed of 2500 rpm for 10 seconds and subsequently heated at 1000C for 10 min. Mass of chlorophyll-a are 0.1 mg, 0.2 mg, and 0.3 mg. Thin layers are characterized by UV-Visible Spectrometer Lamda 25 for optical properties and Keithley 2602 for electrical properties. From the UV-Vis showed that absorbance of P3HT:PCBM:Chlorophyll-a are 400-614nm and 620-700 nm. Efficiency of P3HT:PCBM:Chlorophyll-a for mass chlorophyll 0.1 mg, 0.2 mg, and 0.3 mg are 2.68 x 10-2 %, 3.93 x 10-2 %, and 8.79 x 10-2 % respectively.

  10. SMEI 3D RECONSTRUCTION OF A CORONAL MASS EJECTION INTERACTING WITH A COROTATING SOLAR WIND DENSITY ENHANCEMENT: THE 2008 APRIL 26 CME

    SciTech Connect

    Jackson, B. V.; Buffington, A.; Hick, P. P.; Clover, J. M.; Bisi, M. M.; Webb, D. F.

    2010-12-01

    The Solar Mass Ejection Imager (SMEI) has recorded the brightness responses of hundreds of interplanetary coronal mass ejections (CMEs) in the interplanetary medium. Using a three-dimensional (3D) reconstruction technique that derives its perspective views from outward-flowing solar wind, analysis of SMEI data has revealed the shapes, extents, and masses of CMEs. Here, for the first time, and using SMEI data, we report on the 3D reconstruction of a CME that intersects a corotating region marked by a curved density enhancement in the ecliptic. Both the CME and the corotating region are reconstructed and demonstrate that the CME disrupts the otherwise regular density pattern of the corotating material. Most of the dense CME material passes north of the ecliptic and east of the Sun-Earth line: thus, in situ measurements in the ecliptic near Earth and at the Solar-TErrestrial RElations Observatory Behind spacecraft show the CME as a minor density increase in the solar wind. The mass of the dense portion of the CME is consistent with that measured by the Large Angle Spectrometric Coronagraph on board the Solar and Heliospheric Observatory spacecraft, and is comparable to the masses of many other three-dimensionally reconstructed solar wind features at 1 AU observed in SMEI 3D reconstructions.

  11. The Solar Mass Ejection Imager

    NASA Technical Reports Server (NTRS)

    Jackson, B. V.; Buffington, A.; Hick, P. L.; Kahler, S. W.; Altrock, R. C.; Gold, R. E.; Webb, D. F.

    1995-01-01

    We are designing a Solar Mass Ejection Imager (SMEI) capable of observing the Thomson-scattered signal from transient density features in the heliosphere from a spacecraft situated near AU. The imager is designed to trace these features, which include coronal mass ejections. corotating structures and shock waves, to elongations greater than 90 deg from the Sun. The instrument may be regarded as a progeny of the heliospheric imaging capability shown possible by the zodiacal-light photometers of the HELIOS spacecraft. The instrument we are designing would make more effective use of in-situ solar wind data from spacecraft in the vicinity of the imager by extending these observations to the surrounding environment. The observations from the instrument should allow deconvolution of these structures from the perspective views obtained as they pass the spacecraft. An imager at Earth could allow up to three days warning of the arrival of a mass ejection from the Sun .

  12. Solar mass emission and climate

    NASA Astrophysics Data System (ADS)

    Mursula, Kalevi

    2016-07-01

    The properties of the solar wind and the heliospheric magnetic field (HMF) have been directly measured by satellite observations since the early 1960s, thus covering only the declining phase of the Grand modern maximum (GMM) of solar activity. The information on the properties of solar wind and HMF in the earlier decades is based on different indices of geomagnetic activity, based on observations of the geomagnetic field since the 1840s. While the 19th century is covered by a rather small number of observations, there are several independent series of observations from the early 1900s onwards, yielding a fairly reliable view of solar wind and HMF over the whole GMM. Geomagnetic activity is mainly produced by two major solar wind structures: coronal mass ejections (CME) and high-speed solar wind streams (HSS), whose properties and occurrences differ notably. While CMEs cause the most dramatic individual storms, HSSs are the most effective long-term driver of magnetospheric energetic particles, for which homogeneous, long-term databases of fluxes have recently become available. The new long-term information also allows interesting possibilities to more reliably study the long-term evolution of solar effects in the Earth's atmosphere and climate. E.g., there is evidence that processes related to HSSs may modulate regional/hemispheric climate patterns, in particular the NAO/NAM oscillation. Moreover, other, independent climate effects due to the HMF have been suggested. We review the different approaches used to obtain information on the centennial solar wind and HMF, as well as their suggested atmospheric and climatic effects.

  13. Neutrino masses and solar neutrinos

    SciTech Connect

    Wolfenstein, L.

    1992-11-01

    It has been pointed out by Bahcall and Bethe and others that all solar neutrino data can be explained by MSW oscillations with m({nu}{sub {mu}}) {approximately} 10{sup {minus}3} eV consistent with ideas grand unified theories (GUTS). There is a second possibility consistent with GUTS ideas with m({nu}{sub {tau}}) {approximately} 10{sup {minus}2} eV and m({nu} {sub {mu}}) {approximately} 10 {sup {minus}4} eV. The two cases can be distinguished by a measurement of the solar neutrinos from {sup {tau}}Be.

  14. Submillimetre galaxies reside in dark matter haloes with masses greater than 3 × 10(11) solar masses.

    PubMed

    Amblard, Alexandre; Cooray, Asantha; Serra, Paolo; Altieri, B; Arumugam, V; Aussel, H; Blain, A; Bock, J; Boselli, A; Buat, V; Castro-Rodríguez, N; Cava, A; Chanial, P; Chapin, E; Clements, D L; Conley, A; Conversi, L; Dowell, C D; Dwek, E; Eales, S; Elbaz, D; Farrah, D; Franceschini, A; Gear, W; Glenn, J; Griffin, M; Halpern, M; Hatziminaoglou, E; Ibar, E; Isaak, K; Ivison, R J; Khostovan, A A; Lagache, G; Levenson, L; Lu, N; Madden, S; Maffei, B; Mainetti, G; Marchetti, L; Marsden, G; Mitchell-Wynne, K; Nguyen, H T; O'Halloran, B; Oliver, S J; Omont, A; Page, M J; Panuzzo, P; Papageorgiou, A; Pearson, C P; Pérez-Fournon, I; Pohlen, M; Rangwala, N; Roseboom, I G; Rowan-Robinson, M; Portal, M Sánchez; Schulz, B; Scott, Douglas; Seymour, N; Shupe, D L; Smith, A J; Stevens, J A; Symeonidis, M; Trichas, M; Tugwell, K; Vaccari, M; Valiante, E; Valtchanov, I; Vieira, J D; Vigroux, L; Wang, L; Ward, R; Wright, G; Xu, C K; Zemcov, M

    2011-02-24

    The extragalactic background light at far-infrared wavelengths comes from optically faint, dusty, star-forming galaxies in the Universe with star formation rates of a few hundred solar masses per year. These faint, submillimetre galaxies are challenging to study individually because of the relatively poor spatial resolution of far-infrared telescopes. Instead, their average properties can be studied using statistics such as the angular power spectrum of the background intensity variations. A previous attempt at measuring this power spectrum resulted in the suggestion that the clustering amplitude is below the level computed with a simple ansatz based on a halo model. Here we report excess clustering over the linear prediction at arcminute angular scales in the power spectrum of brightness fluctuations at 250, 350 and 500 μm. From this excess, we find that submillimetre galaxies are located in dark matter haloes with a minimum mass, M(min), such that log(10)[M(min)/M(⊙)] = 11.5(+0.7)(-0.2) at 350 μm, where M(⊙) is the solar mass. This minimum dark matter halo mass corresponds to the most efficient mass scale for star formation in the Universe, and is lower than that predicted by semi-analytical models for galaxy formation.

  15. Mass motion in solar flares

    NASA Technical Reports Server (NTRS)

    Sturrock, P. A.

    1973-01-01

    Mass motions in solar flares are here considered in terms of a previously proposed model. Particle acceleration occurs during reconnection of a current sheet located at coronal heights. The downward component of the particle flux produces an impulsive hard X-ray burst and heats the upper layers of the chromosphere sufficiently to lead to explosive evaporation. Some of the evaporated gas remains trapped in newly closed magnetic field lines and is responsible for the soft thermal component of X-ray emission. Gas which flows along open magnetic field lines subsequently forms a plasmoid which is ejected by magnetic stresses into interplanetary space and may subsequently cause a geomagnetic storm. Analysis of a highly simplified model leads to formulas for the density, temperature, and other parameters of the flare-produced plasma in terms of a length scale and mean magnetic field strength for the flare.

  16. Mass ejections. [during solar flares

    NASA Technical Reports Server (NTRS)

    Rust, D. M.; Hildner, E.; Hansen, R. T.; Dryer, M.; Mcclymont, A. N.; Mckenna-Lawlor, S. M. P.; Mclean, D. J.; Schmahl, E. J.; Steinolfson, R. S.; Tandberg-Hanssen, E.

    1980-01-01

    Observations and model simulations of solar mass ejection phenomena are examined in an investigation of flare processes. Consideration is given to Skylab and other observations of flare-associated sprays, eruptive prominences, surges and coronal transients, and to MHD, gas dynamic and magnetic loop models developed to account for them. Magnetic forces are found to confine spray material, which originates in preexisting active-region filaments, within steadily expanding loops, while surges follow unmoving, preexisting magnetic field lines. Simulations of effects of a sudden pressure pulse at the bottom of the corona are found to exhibit many characteristics of coronal transients associated with flares, and impulsive heating low in the chromosphere is found to be able to account for surges. The importance of the magnetic field as the ultimate source of energy which drives eruptive phenomena as well as flares is pointed out.

  17. Early solar mass loss, element diffusion, and solar oscillation frequencies

    SciTech Connect

    Guzik, J.A.; Cox, A.N.

    1994-07-01

    Swenson and Faulkner, and Boothroyd et al. investigated the possibility that early main-sequence mass loss via a stronger early solar wind could be responsible for the observed solar lithium and beryllium depiction. This depletion requires a total mass loss of {approximately}0.1 M{circle_dot}, nearly independent of the mass loss timescale. We have calculated the evolution and oscillation frequencies of solar models including helium and element diffusion, and such early solar mass loss. We show that extreme mass loss of 1 M{circle_dot} is easily ruled out by the low-degree p-modes that probe the solar center and sense the steeper molecular weight gradient produced by the early phase of more rapid hydrogen burning. The effects on central structure are much smaller for models with an initial mass of 1.1 M{circle_dot} and exponentially-decreasing mass loss irate with e-folding timescale 0.45 Gyr. While such mass loss slightly worsens the agreement between observed and calculated low-degree modes, the observational uncertainties of several tenths of a microhertz weaken this conclusion. Surprisingly, the intermediate-degree modes with much smaller observational uncertainties that probe the convection zone bottom prove to be the key to discriminating between models: The early mass loss phase decreases the total amount of helium and heavier elements diffused from the convection zone, and the extent of the diffusion produced composition gradient just below the convection zone, deteriorating the agreement with observed frequencies for these modes. Thus it appears that oscillations can also rule out this smaller amount of gradual early main-sequence mass loss in the young Sun. The mass loss phase must be confined to substantially under a billion years, probably 0.5 Gyr or less, to simultaneously solve the solar Li/Be problem and avoid discrepancies with solar oscillation frequencies.

  18. 3D numerical study of the propagation characteristics of a consequence of coronal mass ejections in a structured ambient solar wind

    NASA Astrophysics Data System (ADS)

    Zhou, Y.; Feng, X. S.

    2015-12-01

    CMEs have been identified as a prime causal link between solar activity and large, nonrecurrent geomagnetic storm. In order to improve geomagnetic storm predictions, a careful study of CME's propagation characteristics is important. Here, we analyze and quantitatively study the evolution and propagation characteristics of coronal mass ejections (CMEs) launched at several positions into a structured real ambient solar wind by using a three-dimensional (3D) numerical magnetohydrodynamics (MHD) simulation. The ambient solar wind structure during Carrington rotation 2095 is selected, which is an appropriate around activity minimum and declining phase. The CME is initiated by a simple spherical plasmoid model: a spheromak magnetic structure with high speed, high pressure and high plasma density plasmoid. We present a detailed analysis of the plasma, magnetic field, geoeffectiveness, and composition signatures of these CMEs. Results show that the motion and local appearance of a CME in interplanetary space is strongly affected by its interaction with the background solar wind structure, including its velocity, density, and magnetic structures. The simulations show that the initial launched position substantially affects the IP evolution of the CMEs influencing the propagation velocity, the shape, the trajectory and even the geo-effectiveness

  19. Status of the Solar Mass Ejection Imager

    NASA Astrophysics Data System (ADS)

    Johnston, J. C.; Radick, R. R.; Webb, D. F.

    2001-05-01

    The Solar Mass Ejection Imager (SMEI) is a proof-of-concept experiment designed to detect and track coronal mass ejections (CMEs) as they propagate from the Sun through interplanetary space to the Earth and beyond. SMEI will Image CMEs by sensing sunlight scattered from the free electrons in these structures (Thomson scattering). SMEI will be launched by a Titan II rocket into a circular, sun-synchronous (830 km) orbit in 2002 as part of the Space Test Program's CORIOLIS mission. SMEI will image the entire sky once per spacecraft orbit over a mission lifetime of three years. The major subsystems of SMEI are three electronic camera assemblies and a data-handling unit. Each camera consists of a baffle, a radiator, a bright object sensor, an electronics box, and a strongbox containing a shutter, optics and a CCD. Each camera images a 3x60 degree field. Together, they view a 180-degree slice of sky, and sweep over the entire sky once per orbit. SMEI's basic data product will be a 100-minute cadence of all-sky maps of heliospheric brightness, with stars removed, having an angular resolution of about one degree and a photometric precision of about 0.1%. Successful operation of SMEI will represent a major step in improving space weather forecasts. When combined with in-situ solar wind measurements from upstream monitors such as WIND and ACE, SMEI will provide one- to three-day predictions of impending geomagnetic storms at the Earth. SMEI will complement missions such as SoHO, GOES SXI, Solar-B, and STEREO by providing data relating solar drivers to terrestrial effects. Other benefits of SMEI will include observations of variable stars, extra-Solar planetary transits, novae and supernovae, comets and asteroids. The SMEI experiment is being designed and constructed by a team of scientists and engineers from the Air Force Research Laboratory, the University of Birmingham (UB) in the United Kingdom, the University of California at San Diego (UCSD), and Boston University. The

  20. EVIDENCE FOR HIGH-FREQUENCY QPOs WITH A 3:2 FREQUENCY RATIO FROM A 5000 SOLAR MASS BLACK HOLE

    SciTech Connect

    Pasham, Dheeraj R.; Cenko, S. Bradley; Mushotzky, Richard F.; Tombesi, Francesco; Zoghbi, Abderahmen; Miller, Jon E-mail: brad.cenko@nasa.gov E-mail: richard@astro.umd.edu E-mail: jonmm@umich.edu

    2015-09-20

    Following the discovery of 3:2 resonance quasi-periodic oscillations (QPOs) in M82X-1, we have constructed power density spectra (PDS) of all 15 (sufficiently long) XMM-Newton observations of the ultraluminous X-ray source NGC 1313 X-1 (L{sub X} ≈ 2 × 10{sup 40} erg s{sup −1}). We detect a strong QPO at a frequency of 0.29 ± 0.01 Hz in data obtained on 2012 December 16. Subsequent searching of all the remaining observations for a 3:2/2:3 frequency pair revealed a feature at 0.46 ± 0.02 Hz on 2003 December 13 (frequency ratio of 1.59 ± 0.09). The global significance of the 0.29 Hz feature considering all frequencies between 0.1 and 4 Hz is >3.5σ. The significance of the 0.46 ± 0.02 Hz QPO is >3.5σ for a search at 2/3 and 3/2 of 0.29 Hz. We also detect lower-frequency QPOs (32.9 ± 2.6 and 79.7 ± 1.2 mHz). All the QPOs are superimposed on a continuum consisting of flat-topped, band-limited noise, breaking into a power law at a frequency of 16 ± 3 mHz and white noise at ≳0.1 Hz. NGC 1313 X-1's PDS is analogous to stellar-mass black holes’ (StMBHs) PDS in the so-called steep power-law state, but with the respective frequencies (both QPOs and break frequencies) scaled down by a factor of ∼1000. Using the inverse mass-to-high-frequency QPO scaling of StMBHs, we estimate NGC 1313 X-1's black hole mass to be 5000 ± 1300 M{sub ⊙}, consistent with an inference from the scaling of the break frequency. However, the implied Eddington ratio, L{sub Edd} > 0.03 ± 0.01, is significantly lower compared to that of StMBHs in the steep power-law state (L{sub Edd} ≳ 0.2)

  1. Mass properties survey of solar array technologies

    NASA Technical Reports Server (NTRS)

    Kraus, Robert

    1991-01-01

    An overview of the technologies, electrical performance, and mass characteristics of many of the presently available and the more advanced developmental space solar array technologies is presented. Qualitative trends and quantitative mass estimates as total array output power is increased from 1 kW to 5 kW at End of Life (EOL) from a single wing are shown. The array technologies are part of a database supporting an ongoing solar power subsystem model development for top level subsystem and technology analyses. The model is used to estimate the overall electrical and thermal performance of the complete subsystem, and then calculate the mass and volume of the array, batteries, power management, and thermal control elements as an initial sizing. The array types considered here include planar rigid panel designs, flexible and rigid fold-out planar arrays, and two concentrator designs, one with one critical axis and the other with two critical axes. Solar cell technologies of Si, GaAs, and InP were included in the analyses. Comparisons were made at the array level; hinges, booms, harnesses, support structures, power transfer, and launch retention mountings were included. It is important to note that the results presented are approximations, and in some cases revised or modified performance and mass estimates of specific designs.

  2. COMPREHENSIVE ANALYSIS OF CORONAL MASS EJECTION MASS AND ENERGY PROPERTIES OVER A FULL SOLAR CYCLE

    SciTech Connect

    Vourlidas, A.; Howard, R. A.; Esfandiari, E.; Patsourakos, S.; Yashiro, S.; Michalek, G.

    2010-10-20

    The LASCO coronagraphs, in continuous operation since 1995, have observed the evolution of the solar corona and coronal mass ejections (CMEs) over a full solar cycle with high-quality images and regular cadence. This is the first time that such a data set becomes available and constitutes a unique resource for the study of CMEs. In this paper, we present a comprehensive investigation of the solar cycle dependence on the CME mass and energy over a full solar cycle (1996-2009) including the first in-depth discussion of the mass and energy analysis methods and their associated errors. Our analysis provides several results worthy of further studies. It demonstrates the possible existence of two event classes: 'normal' CMEs reaching constant mass for >10 R{sub sun} and {sup p}seudo{sup -}CMEs which disappear in the C3 field of view. It shows that the mass and energy properties of CME reach constant levels and therefore should be measured only above {approx}10 R{sub sun}. The mass density (g/R {sup 2}{sub sun}) of CMEs varies relatively little (< order of magnitude) suggesting that the majority of the mass originates from a small range in coronal heights. We find a sudden reduction in the CME mass in mid-2003 which may be related to a change in the electron content of the large-scale corona and we uncover the presence of a 6 month periodicity in the ejected mass from 2003 onward.

  3. Solar Eruptions: Coronal Mass Ejections and Flares

    NASA Technical Reports Server (NTRS)

    Gopalswamy, Nat

    2012-01-01

    This lecture introduces the topic of Coronal mass ejections (CMEs) and solar flares, collectively known as solar eruptions. During solar eruptions, the released energy flows out from the Sun in the form of magnetized plasma and electromagnetic radiation. The electromagnetic radiation suddenly increases the ionization content of the ionosphere, thus impacting communication and navigation systems. Flares can be eruptive or confined. Eruptive flares accompany CMEs, while confined flares hav only electromagnetic signature. CMEs can drive MHD shocks that accelerate charged particles to very high energies in the interplanetary space, which pose radiation hazard to astronauts and space systems. CMEs heading in the direction of Earth arrive in about two days and impact Earth's magnetosphere, producing geomagnetic storms. The magnetic storms result in a number of effects including induced currnts that can disrupt power grids, railroads, and underground pipelines

  4. Energetics of solar coronal mass ejections

    NASA Astrophysics Data System (ADS)

    Subramanian, P.; Vourlidas, A.

    2007-05-01

    Aims:We investigate whether solar coronal mass ejections are driven mainly by coupling to the ambient solar wind or through the release of internal magnetic energy. Methods: We examine the energetics of 39 flux-rope like coronal mass ejections (CMEs) from the Sun using data in the distance range ~2-20 R⊙ from the Large Angle Spectroscopic Coronograph (LASCO) aboard the Solar and Heliospheric Observatory (SOHO). This comprises a complete sample of the best examples of flux-rope CMEs observed by LASCO in 1996-2001. Results: We find that 69% of the CMEs in our sample experience a clearly identifiable driving power in the LASCO field of view. For those CMEs that are driven, we examine if they might be deriving most of their driving power by coupling to the solar wind. We do not find conclusive evidence in favor of this hypothesis. On the other hand, we find that their internal magnetic energy is a viable source of the required driving power. We have estimated upper and lower limits on the power that can possibly be provided by the internal magnetic field of a CME. We find that, on average, the lower limit to the available magnetic power is around 74% of what is required to drive the CMEs, while the upper limit can be as much as an order of magnitude larger.

  5. Collapse of 9 solar mass stars

    NASA Technical Reports Server (NTRS)

    Baron, E.; Cooperstein, J.; Kahana, S.

    1987-01-01

    General relativistic hydrodynamical calculations of the collapse of O + Ne + Mg cores of a 9 solar mass star are reported. Collapse is induced by rapid electron captures as the O + Ne + Mg is burned to nuclear statistical equilibrium. The high entropy in the core after burning leads to a large abundance of free protons which readily capture electrons. This leads to large neutrino losses and a correspondingly small infalling homologous core. The hydrodynamic shock thus forms at a small mass point. The shock stalls before reaching the edge of the O + Ne + Mg core and thereby fails to produce a successful supernova explosion by the direct mechanism. No enhancement in the shock energy due to nuclear burning is found.

  6. Comprehensive Analysis of Coronal Mass Ejection Mass and Energy Properties Over a Full Solar Cycle

    DTIC Science & Technology

    2010-01-01

    the evolution of the solar corona and coronal mass ejections (CMEs) over a full solar cycle with high quality images and regular cadence. This is the...observed the evolution of the solar corona and coronal mass ejections (CMEs) over a full solar cycle with high quality images and regular cadence. This is...1985) and Vourlidas et al. (2002). We discuss several aspects that emerge from the statistical analysis of such a large event sample such as solar

  7. V are Interplanetary Coronal Mass Ejections Observed with the SOlar Mass Ejection Imager

    DTIC Science & Technology

    2007-01-01

    SUBTITLE V arc interplanetary coronal mass ejections observed with the Solar Mass Ejection Imager 5a. CONTRACT NUMBER 5b. GRANT NUMBER a. 5c...doi: 10.1029/2007JA012358 14. ABSTRACT Since February 2003, The Solar Mass Ejection Imager (SMEI) has been observing interplanetary- coronal mass...ejections (ICMEs) at solar elongation angles ^ > 20 degrees. The ICMEs generally appear as loops or arcs in the sky, but five show distinct outward

  8. Stars Just Got Bigger - A 300 Solar Mass Star Uncovered

    NASA Astrophysics Data System (ADS)

    2010-07-01

    raises the challenge to theorists still further. "Either they were born so big or smaller stars merged together to produce them," explains Crowther. Stars between about 8 and 150 solar masses explode at the end of their short lives as supernovae, leaving behind exotic remnants, either neutron stars or black holes. Having now established the existence of stars weighing between 150 and 300 solar masses, the astronomers' findings raise the prospect of the existence of exceptionally bright, "pair instability supernovae" that completely blow themselves apart, failing to leave behind any remnant and dispersing up to ten solar masses of iron into their surroundings. A few candidates for such explosions have already been proposed in recent years. Not only is R136a1 the most massive star ever found, but it also has the highest luminosity too, close to 10 million times greater than the Sun. "Owing to the rarity of these monsters, I think it is unlikely that this new record will be broken any time soon," concludes Crowther. Notes [1] The star A1 in NGC 3603 is a double star, with an orbital period of 3.77 days. The two stars in the system have, respectively, 120 and 92 times the mass of the Sun, which means that they have formed as stars weighing, respectively, 148 and 106 solar masses. [2] The team used the SINFONI, ISAAC and MAD instruments, all attached to ESO's Very Large Telescope at Paranal, Chile. [3] (note added on 26 July 2010) The "bigger" in the title does not imply that these stars are the biggest observed. Such stars, called red supergiants, can have radii up to about a thousand solar radii, while R136a1, which is blue, is about 35 times as large as the Sun. However, R136a1 is the star with the greatest mass known to date. More information This work is presented in an article published in the Monthly Notices of the Royal Astronomical Society ("The R136 star cluster hosts several stars whose individual masses greatly exceed the accepted 150 Msun stellar mass limit", by

  9. Mass drivers. 3: Engineering

    NASA Technical Reports Server (NTRS)

    Arnold, W.; Bowen, S.; Cohen, S.; Fine, K.; Kaplan, D.; Kolm, M.; Kolm, H.; Newman, J.; Oneill, G. K.; Snow, W.

    1979-01-01

    The last of a series of three papers by the Mass-Driver Group of the 1977 Ames Summer Study is presented. It develops the engineering principles required to implement the basic mass-driver. Optimum component mass trade-offs are derived from a set of four input parameters, and the program used to design a lunar launcher. The mass optimization procedures is then incorporated into a more comprehensive mission optimization program called OPT-4, which evaluates an optimized mass-driver reaction engine and its performance in a range of specified missions. Finally, this paper discusses, to the extent that time permitted, certain peripheral problems: heating effects in buckets due to magnetic field ripple; an approximate derivation of guide force profiles; the mechanics of inserting and releasing payloads; the reaction mass orbits; and a proposed research and development plan for implementing mass drivers.

  10. Solar origins of coronal mass ejections

    NASA Technical Reports Server (NTRS)

    Kahler, Stephen

    1987-01-01

    The large scale properties of coronal mass ejections (CMEs), such as morphology, leading edge speed, and angular width and position, have been cataloged for many events observed with coronagraphs on the Skylab, P-78, and SMM spacecraft. While considerable study has been devoted to the characteristics of the SMEs, their solar origins are still only poorly understood. Recent observational work has involved statistical associations of CMEs with flares and filament eruptions, and some evidence exists that the flare and eruptive-filament associated CMEs define two classes of events, with the former being generally more energetic. Nevertheless, it is found that eruptive-filament CMEs can at times be very energetic, giving rise to interplanetary shocks and energetic particle events. The size of the impulsive phase in a flare-associated CME seems to play no significant role in the size or speed of the CME, but the angular sizes of CMEs may correlate with the scale sizes of the 1-8 angstrom x-ray flares. At the present time, He 10830 angstrom observations should be useful in studying the late development of double-ribbon flares and transient coronal holes to yield insights into the CME aftermath. The recently available white-light synoptic maps may also prove fruitful in defining the coronal conditions giving rise to CMEs.

  11. The Solar Mass Ejection Imager (SMEI) Space Experiment

    DTIC Science & Technology

    2015-01-30

    SoloHI for Solar Orbiter [84] and WISPR for Solar Probe Plus [85]) that are scheduled for launch near the end of the decade. In addition, other more...Halain, J- P., and Lamy, P. L., “The Solar and Heliospheric Imager (SoloHI) Instrument for the Solar Orbiter Mission,” Proc. SPIE, 8862, Sep 2013...AFRL-RV-PS- AFRL-RV-PS- TR-2014-0197 TR-2014-0197 THE SOLAR MASS EJECTION IMAGER (SMEI) SPACE EXPERIMENT Richard R. Radick 30 January 2015

  12. Mass motion in upper solar chromosphere detected from solar eclipse observation

    NASA Astrophysics Data System (ADS)

    Li, Zhi; Qu, Zhongquan; Yan, Xiaoli; Dun, Guangtao; Chang, Liang

    2016-05-01

    The eclipse-observed emission lines formed in the upper solar atmosphere can be used to diagnose the atmosphere dynamics which provides an insight to the energy balance of the outer atmosphere. In this paper, we analyze the spectra formed in the upper chromospheric region by a new instrument called Fiber Arrayed Solar Optic Telescope (FASOT) around the Gabon total solar eclipse on November 3, 2013. The double Gaussian fits of the observed profiles are adopted to show enhanced emission in line wings, while red-blue (RB) asymmetry analysis informs that the cool line (about 104 K) profiles can be decomposed into two components and the secondary component is revealed to have a relative velocity of about 16-45 km s^{-1}. The other profiles can be reproduced approximately with single Gaussian fits. From these fittings, it is found that the matter in the upper solar chromosphere is highly dynamic. The motion component along the line-of-sight has a pattern asymmetric about the local solar radius. Most materials undergo significant red shift motions while a little matter show blue shift. Despite the discrepancy of the motion in different lines, we find that the width and the Doppler shifts both are function of the wavelength. These results may help us to understand the complex mass cycle between chromosphere and corona.

  13. The solar wind mass flux problem

    NASA Technical Reports Server (NTRS)

    Leer, E.; Holzer, T. E.

    1991-01-01

    The variation of the proton flux with coronal temperature and density in thermally driven solar wind models is discussed. It is shown that the rapid increase of the proton flux with increasing temperature can be reduced by adiabatic cooling of the expanding plasma. A significant coronal helium abundance can also act as a 'regulator' for the solar wind proton flux.

  14. What accelerator mass spectrometry can do for solar physics

    NASA Astrophysics Data System (ADS)

    Newkirk, Gordon

    1984-11-01

    We review some of the empirical aspects of the solar magnetic activity and the convective dynamo models developed to account for the magnetic cycle. Alternative hypotheses which have recently emerged are sketched. Possible applications of accelerator mass spectrometry to solar physics and the important questions that proxy data on past solar activity might answer are evaluated. The National Center for Atmospheric Research is sponsored by the National Science Foundation.

  15. The Automatic Detection of Coronal Mass Ejections Using the Solar Mass Ejection Imager

    DTIC Science & Technology

    2009-10-30

    Res., 112, A09103, doi: 10.1029/2007JA012358, 2007. Low, B.C., Solar activity and the corona , Solar Phys. 167, p217, 1996. Robbrecht, E., and D...AFRL-RV-HA-TR-2009-1104 Q- o o o p o The Automatic Detection of Coronal Mass Ejections Using the Solar Mass Ejection Imager Timothy A. Howard... Solar Mass Ejection Imager 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6340IF 6. AUTHORS Timothy A. Howard S. James Tappin

  16. Genesis Solar Wind Interstream, Coronal Hole and Coronal Mass Ejection Samples: Update on Availability and Condition

    NASA Technical Reports Server (NTRS)

    Allton, J. H.; Gonzalez, C. P.; Allums, K. K.

    2017-01-01

    Recent refinement of analysis of ACE/SWICS data (Advanced Composition Explorer/Solar Wind Ion Composition Spectrometer) and of onboard data for Genesis Discovery Mission of 3 regimes of solar wind at Earth-Sun L1 make it an appropriate time to update the availability and condition of Genesis samples specifically collected in these three regimes and currently curated at Johnson Space Center. ACE/SWICS spacecraft data indicate that solar wind flow types emanating from the interstream regions, from coronal holes and from coronal mass ejections are elementally and isotopically fractionated in different ways from the solar photosphere, and that correction of solar wind values to photosphere values is non-trivial. Returned Genesis solar wind samples captured very different kinds of information about these three regimes than spacecraft data. Samples were collected from 11/30/2001 to 4/1/2004 on the declining phase of solar cycle 23. Meshik, et al is an example of precision attainable. Earlier high precision laboratory analyses of noble gases collected in the interstream, coronal hole and coronal mass ejection regimes speak to degree of fractionation in solar wind formation and models that laboratory data support. The current availability and condition of samples captured on collector plates during interstream slow solar wind, coronal hole high speed solar wind and coronal mass ejections are de-scribed here for potential users of these samples.

  17. ISOTOPIC MASS FRACTIONATION OF SOLAR WIND: EVIDENCE FROM FAST AND SLOW SOLAR WIND COLLECTED BY THE GENESIS MISSION

    SciTech Connect

    Heber, Veronika S.; Baur, Heinrich; Wieler, Rainer; Bochsler, Peter; McKeegan, Kevin D.; Neugebauer, Marcia; Reisenfeld, Daniel B.; Wiens, Roger C.

    2012-11-10

    NASA's Genesis space mission returned samples of solar wind collected over {approx}2.3 years. We present elemental and isotopic compositions of He, Ne, and Ar analyzed in diamond-like carbon targets from the slow and fast solar wind collectors to investigate isotopic fractionation processes during solar wind formation. The solar wind provides information on the isotopic composition for most volatile elements for the solar atmosphere, the bulk Sun and hence, on the solar nebula from which it formed 4.6 Ga ago. Our data reveal a heavy isotope depletion in the slow solar wind compared to the fast wind composition by 63.1 {+-} 2.1 per mille for He, 4.2 {+-} 0.5 per mille amu{sup -1} for Ne and 2.6 {+-} 0.5 per mille amu{sup -1} for Ar. The three Ne isotopes suggest that isotopic fractionation processes between fast and slow solar wind are mass dependent. The He/H ratios of the collected slow and fast solar wind samples are 0.0344 and 0.0406, respectively. The inefficient Coulomb drag model reproduces the measured isotopic fractionation between fast and slow wind. Therefore, we apply this model to infer the photospheric isotopic composition of He, Ne, and Ar from our solar wind data. We also compare the isotopic composition of oxygen and nitrogen measured in the solar wind with values of early solar system condensates, probably representing solar nebula composition. We interpret the differences between these samples as being due to isotopic fractionation during solar wind formation. For both elements, the magnitude and sign of the observed differences are in good agreement with the values predicted by the inefficient Coulomb drag model.

  18. High temperature - low mass solar blanket

    NASA Technical Reports Server (NTRS)

    Mesch, H. G.

    1979-01-01

    Interconnect materials and designs for use with ultrathin silicon solar cells are discussed, as well as the results of an investigation of the applicability of parallel-gap resistance welding for interconnecting these cells. Data relating contact pull strength and cell electrical degradation to variations in welding parameters such as time, voltage and pressure are presented. Methods for bonding ultrathin cells to flexible substances and for bonding thin (75 micrometers) covers to these cells are described. Also, factors influencing fabrication yield and approaches for increasing yield are discussed. The results of vacuum thermal cycling and thermal soak tests on prototype ultrathin cell test coupons and one solar module blanket are presented.

  19. Interplanetary Coronal Mass Ejections in the Near-Earth Solar Wind During 1996-2002

    NASA Technical Reports Server (NTRS)

    Cane, H. V.; Richardson, I. G.

    2003-01-01

    We summarize the occurrence of interplanetary coronal mass injections (ICMEs) in the near-Earth solar wind during 1996-2002, corresponding to the increasing and maximum phases of solar cycle 23. In particular, we give a detailed list of such events. This list, based on in-situ observations, is not confined to subsets of ICMEs, such as magnetic clouds or those preceded by halo CMEs observed by the SOHO/LASCO coronagraph, and provides an overview of 214 ICMEs in the near-Earth solar wind during this period. The ICME rate increases by about an order of magnitude from solar minimum to solar maximum (when the rate is approximately 3 ICMEs/solar rotation period). The rate also shows a temporary reduction during 1999, and another brief, deeper reduction in late 2000-early 2001, which only approximately track variations in the solar 10 cm flux. In addition, there are occasional periods of several rotations duration when the ICME rate is enhanced in association with high solar activity levels. We find an indication of a periodic variation in the ICME rate, with a prominent period of approximately 165 days similar to that previously reported in various solar phenomena. It is found that the fraction of ICMEs that are magnetic clouds has a solar cycle variation, the fraction being larger near solar minimum. For the subset of events that we could associate with a CME at the Sun, the transit speeds from the Sun to the Earth were highest after solar maximum.

  20. Solar heater/cooler for mass market

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Electrical energy consumption is reduced by half for 2 1/2 story office building. 138 liquid flat plate solar collectors are mounted on building roof, which faces nearly due south. Final project report includes detailed drawings and photographs, operation and maintenance manual, acceptance test plan, and related information.

  1. A 400-solar-mass black hole in the galaxy M82.

    PubMed

    Pasham, Dheeraj R; Strohmayer, Tod E; Mushotzky, Richard F

    2014-09-04

    M82 X-1, the brightest X-ray source in the galaxy M82, has been thought to be an intermediate-mass black hole (100 to 10,000 solar masses) because of its extremely high luminosity and variability characteristics, although some models suggest that its mass may be only about 20 solar masses. The previous mass estimates were based on scaling relations that use low-frequency characteristic timescales which have large intrinsic uncertainties. For stellar-mass black holes, we know that the high-frequency quasi-periodic oscillations (100-450 hertz) in the X-ray emission that occur in a 3:2 frequency ratio are stable and scale in frequency inversely with black hole mass with a reasonably small dispersion. The discovery of such stable oscillations thus potentially offers an alternative and less ambiguous means of mass determination for intermediate-mass black holes, but has hitherto not been realized. Here we report stable, twin-peak (3:2 frequency ratio) X-ray quasi-periodic oscillations from M82 X-1 at frequencies of 3.32 ± 0.06 hertz and 5.07 ± 0.06 hertz. Assuming that we can extrapolate the inverse-mass scaling that holds for stellar-mass black holes, we estimate the black hole mass of M82 X-1 to be 428 ± 105 solar masses. In addition, we can estimate the mass using the relativistic precession model, from which we get a value of 415 ± 63 solar masses.

  2. Solar wind rare gas analysis: Trapped solar wind helium and neon in Surveyor 3 material

    NASA Technical Reports Server (NTRS)

    Buehler, F.; Eberhardt, P.; Geiss, J.; Schwarzmueller, J.

    1972-01-01

    The He-4 and Ne-20 contents in sections of the Surveyor 3 support strut samples were determined by optical and scanning electron microscopy and are compared to the results of the Apollo solar wind composition (SWC) experiments. The He-4/Ne-20 ratio in the samples from the sunlit side of the strut was approximately 300; the ratios determined in Apollo 12 lunar fines and SWC foil were below 100. The He-4/He-3 ratios were also determined, and the ratio obtained from Surveyor 3 material is higher than those found with Apollo 11 and 12 SWC experiments. The effects of spallation by cosmic rays or solar protons, stripping by cosmic ray or energetic solar alpha particles, recycling of solar wind He and radiogenic Ne, He from terrestrial atmosphere, mass discrimination near the moon, mass dependence of trapping probability, diffusion, and contamination by lunar dust are considered.

  3. The X-ray signature of solar coronal mass

    NASA Technical Reports Server (NTRS)

    Harrison, R. A.; Waggett, P. W.; Bentley, R. D.; Phillips, K. J. H.; Bruner, M.

    1985-01-01

    The coronal response to six solar X-ray flares has been investigated. At a time coincident with the projected onset of the white-light coronal mass ejection associated with each flare, there is a small, discrete soft X-ray enhancement. These enhancements (precursors) precede by typically about 20 m the impulsive phase of the solar flare which is dominant by the time the coronal mass ejection has reached an altitude above 0.5 solar radii. Motions of hot X-ray emitting plasma, during the precursors, which may well be a signature of the mass ejection onsets, are identified. Further investigations have also revealed a second class of X-ray coronal transient, during the main phase of the flare. These appear to be associated with magnetic reconnection above post-flare loop systems.

  4. MEASURING THE MASS OF SOLAR SYSTEM PLANETS USING PULSAR TIMING

    SciTech Connect

    Champion, D. J.; Hobbs, G. B.; Manchester, R. N.; Edwards, R. T.; Burke-Spolaor, S.; Sarkissian, J. M.; Backer, D. C.; Bailes, M.; Bhat, N. D. R.; Van Straten, W.; Coles, W.; Demorest, P. B.; Ferdman, R. D.; Purver, M. B.; Folkner, W. M.; Hotan, A. W.; Kramer, M.; Lommen, A. N.; Nice, D. J.; Stairs, I. H.

    2010-09-10

    High-precision pulsar timing relies on a solar system ephemeris in order to convert times of arrival (TOAs) of pulses measured at an observatory to the solar system barycenter. Any error in the conversion to the barycentric TOAs leads to a systematic variation in the observed timing residuals; specifically, an incorrect planetary mass leads to a predominantly sinusoidal variation having a period and phase associated with the planet's orbital motion about the Sun. By using an array of pulsars (PSRs J0437-4715, J1744-1134, J1857+0943, J1909-3744), the masses of the planetary systems from Mercury to Saturn have been determined. These masses are consistent with the best-known masses determined by spacecraft observations, with the mass of the Jovian system, 9.547921(2) x10{sup -4} M {sub sun}, being significantly more accurate than the mass determined from the Pioneer and Voyager spacecraft, and consistent with but less accurate than the value from the Galileo spacecraft. While spacecraft are likely to produce the most accurate measurements for individual solar system bodies, the pulsar technique is sensitive to planetary system masses and has the potential to provide the most accurate values of these masses for some planets.

  5. Automated Detection, Characterisation and Tracking of Solar Coronal Mass Ejections

    NASA Astrophysics Data System (ADS)

    Gallagher, Peter; Carley, Eoin; Byrne, Jason; Morgan, Huw; Refojo, Jose

    Coronal mass ejections (CMEs) are large eruptions of plasma and magnetic flux from the Sun through interplanetary space. If they impact the Earth, they can cause space weather effects that are detrimental to technological systems upon which society is highly dependent. It is therefore important to automatically identify and track CMEs in near-realtime in order to better forecast their possible arrival at Earth. Due to the diffuse nature and comparatively high speeds of CMEs, it is computationally challenging to automatically identify, characterise and track them as they move through the solar corona and inner heliosphere. Here, we review and discuss current state-of-the-art image processing techniques, and how they are being used to automatically generate catalogues of CME properties in near-realtime and for space weather purposes. Furthermore, we discus recent advances in the reconstruction and visualisation of CMEs in 3D, which is crucial to our understanding of their detailed structure and resulting evolution through space.

  6. Global Energetics of Solar Flares. IV. Coronal Mass Ejection Energetics

    NASA Astrophysics Data System (ADS)

    Aschwanden, Markus J.

    2016-11-01

    This study entails the fourth part of a global flare energetics project, in which the mass m cme, kinetic energy E kin, and the gravitational potential energy E grav of coronal mass ejections (CMEs) is measured in 399 M and X-class flare events observed during the first 3.5 years of the Solar Dynamics Observatory (SDO) mission, using a new method based on the EUV dimming effect. EUV dimming is modeled in terms of a radial adiabatic expansion process, which is fitted to the observed evolution of the total emission measure of the CME source region. The model derives the evolution of the mean electron density, the emission measure, the bulk plasma expansion velocity, the mass, and the energy in the CME source region. The EUV dimming method is truly complementary to the Thomson scattering method in white light, which probes the CME evolution in the heliosphere at r ≳ 2 R ⊙, while the EUV dimming method tracks the CME launch in the corona. We compare the CME parameters obtained in white light with the LASCO/C2 coronagraph with those obtained from EUV dimming with the Atmospheric Imaging Assembly onboard the SDO for all identical events in both data sets. We investigate correlations between CME parameters, the relative timing with flare parameters, frequency occurrence distributions, and the energy partition between magnetic, thermal, nonthermal, and CME energies. CME energies are found to be systematically lower than the dissipated magnetic energies, which is consistent with a magnetic origin of CMEs.

  7. Helium (3) Rich Solar Flares

    DOE R&D Accomplishments Database

    Colgate, S. A.; Audouze, J.; Fowler, W. A.

    1977-05-03

    The extreme enrichment of {sup 3} He {sup 4} He greater than or equal to 1 in some solar flares as due to spallation and the subsequent confinement of the products in a high temperature, kT approx. = 200 keV, high density, n{sub e} approx. = 3 x 10{sup 15} cm {sup -3} plasma associated with the magnetic instability producing the flare is interpreted. The pinch or filament is a current of high energy protons that creates the spallation and maintains the temperature that produces the high energy x-ray spectrum and depletes other isotopes D, Li, Be, and B as observed. Finally the high temperature plasma is a uniquely efficient spallation target that is powered by the interaction of stellar convection and self generated magnetic field.

  8. Age and mass of solar twins constrained by lithium abundance

    NASA Astrophysics Data System (ADS)

    Do Nascimento, J. D., Jr.; Castro, M.; Meléndez, J.; Bazot, M.; Théado, S.; Porto de Mello, G. F.; de Medeiros, J. R.

    2009-07-01

    Aims: We analyze the non-standard mixing history of the solar twins HIP 55 459, HIP 79 672, HIP 56 948, HIP 73 815, and HIP 100 963, to determine as precisely as possible their mass and age. Methods: We computed a grid of evolutionary models with non-standard mixing at several metallicities with the Toulouse-Geneva code for a range of stellar masses assuming an error bar of ±50 K in T_eff. We choose the evolutionary model that reproduces accurately the observed low lithium abundances observed in the solar twins. Results: Our best-fit model for each solar twin provides a mass and age solution constrained by their Li content and T_eff determination. HIP 56 948 is the most likely solar-twin candidate at the present time and our analysis infers a mass of 0.994 ± 0.004 {M⊙} and an age of 4.71 ± 1.39 Gyr. Conclusions: Non-standard mixing is required to explain the low Li abundances observed in solar twins. Li depletion due to additional mixing in solar twins is strongly mass dependent. An accurate lithium abundance measurement and non-standard models provide more precise information about the age and mass more robustly than determined by classical methods alone. The models are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/501/687 or via http://andromeda.dfte.ufrn.br

  9. Tracking Coronal Mass Ejections with a Heliospheric Imager: Case Studies from the Solar Mass Ejection Imager

    NASA Astrophysics Data System (ADS)

    Johnston, J. C.; Mizuno, D. R.; Webb, D. F.; Kuchar, T. A.; Howard, T. A.

    2005-05-01

    The Solar Mass Ejection Imager (SMEI) was launched on board the DoD Space Test Program's Coriolis satellite in January 2003. Two-thirds through its planned 3-year lifetime, SMEI has observed Coronal Mass Ejections (CMEs), comets and asteroids as they move through the heliosphere. More than 140 CMEs have been detected with the SMEI instrument, including well-documented "halo" events that led to geomagnetic storm conditions on Earth. These observations demonstrate the potential of a heliospheric imager for space weather specification and prediction purposes. We present several case studies of CMEs as they propagate through the SOHO LASCO and SMEI fields of view, and examine SMEI's "hit" rate for detection of geoeffective CMEs.

  10. Ion implantation of solar cell junctions without mass analysis

    NASA Technical Reports Server (NTRS)

    Fitzgerald, D.; Tonn, D. G.

    1981-01-01

    This paper is a summary of an investigation to determine the feasibility of producing solar cells by means of ion implantation without the use of mass analysis. Ion implants were performed using molecular and atomic phosphorus produced by the vaporization of solid red phosphorus and ionized in an electron bombardment source. Solar cell junctions were ion implanted by mass analysis of individual molecular species and by direct unanalyzed implants from the ion source. The implant dose ranged from 10 to the 14th to 10 to the 16th atoms/sq cm and the energy per implanted atom ranged from 5 KeV to 40 KeV in this study.

  11. Matrix-assisted laser desorption/ionization mass spectrometric analysis of poly(3,4-ethylenedioxythiophene) in solid-state dye-sensitized solar cells: comparison of in situ photoelectrochemical polymerization in aqueous micellar and organic media.

    PubMed

    Zhang, Jinbao; Ellis, Hanna; Yang, Lei; Johansson, Erik M J; Boschloo, Gerrit; Vlachopoulos, Nick; Hagfeldt, Anders; Bergquist, Jonas; Shevchenko, Denys

    2015-04-07

    Solid-state dye-sensitized solar cells (sDSCs) are devoid of such issues as electrolyte evaporation or leakage and electrode corrosion, which are typical for traditional liquid electrolyte-based DSCs. Poly(3,4-ethylenedioxythiophene) (PEDOT) is one of the most popular and efficient p-type conducting polymers that are used in sDSCs as a solid-state hole-transporting material. The most convenient way to deposit this insoluble polymer into the dye-sensitized mesoporous working electrode is in situ photoelectrochemical polymerization. Apparently, the structure and the physicochemical properties of the generated conducting polymer, which determine the photovoltaic performance of the corresponding solar cell, can be significantly affected by the preparation conditions. Therefore, a simple and fast analytical method that can reveal information on polymer chain length, possible chemical modifications, and impurities is strongly required for the rapid development of efficient solar energy-converting devices. In this contribution, we applied matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) for the analysis of PEDOT directly on sDSCs. It was found that the PEDOT generated in aqueous micellar medium possesses relatively shorter polymeric chains than the PEDOT deposited from an organic medium. Furthermore, the micellar electrolyte promotes a transformation of one of the thiophene terminal units to thiophenone. The introduction of a carbonyl group into the PEDOT molecule impedes the growth of the polymer chain and reduces the conductivity of the final polymer film. Both the simplicity of sample preparation (only application of the organic matrix onto the solar cell is needed) and the rapidity of analysis hold the promise of making MALDI MS an essential tool for the physicochemical characterization of conducting polymer-based sDSCs.

  12. Solar flares, coronal mass ejections and solar energetic particle event characteristics

    NASA Astrophysics Data System (ADS)

    Papaioannou, Athanasios; Sandberg, Ingmar; Anastasiadis, Anastasios; Kouloumvakos, Athanasios; Georgoulis, Manolis K.; Tziotziou, Kostas; Tsiropoula, Georgia; Jiggens, Piers; Hilgers, Alain

    2016-12-01

    A new catalogue of 314 solar energetic particle (SEP) events extending over a large time span from 1984 to 2013 has been compiled. The properties as well as the associations of these SEP events with their parent solar sources have been thoroughly examined. The properties of the events include the proton peak integral flux and the fluence for energies above 10, 30, 60 and 100 MeV. The associated solar events were parametrized by solar flare (SF) and coronal mass ejection (CME) characteristics, as well as related radio emissions. In particular, for SFs: the soft X-ray (SXR) peak flux, the SXR fluence, the heliographic location, the rise time and the duration were exploited; for CMEs the plane-of-sky velocity as well as the angular width were utilized. For radio emissions, type III, II and IV radio bursts were identified. Furthermore, we utilized element abundances of Fe and O. We found evidence that most of the SEP events in our catalogue do not conform to a simple two-class paradigm, with the 73% of them exhibiting both type III and type II radio bursts, and that a continuum of event properties is present. Although, the so-called hybrid or mixed events are found to be present in our catalogue, it was not possible to attribute each SEP event to a mixed/hybrid sub-category. Moreover, it appears that the start of the type III burst most often precedes the maximum of the SF and thus falls within the impulsive phase of the associated SF. At the same time, type III bursts take place within ≈5.22 min, on average, in advance from the time of maximum of the derivative of the SXR flux (Neupert effect). We further performed a statistical analysis and a mapping of the logarithm of the proton peak flux at E > 10 MeV, on different pairs of the parent solar source characteristics. This revealed correlations in 3-D space and demonstrated that the gradual SEP events that stem from the central part of the visible solar disk constitute a significant radiation risk. The velocity of

  13. High-power, ultralow-mass solar arrays: FY-77 solar arrays technology readiness assessment report, volume 2

    NASA Technical Reports Server (NTRS)

    Costogue, E. N.; Young, L. E.; Brandhorst, H. W., Jr.

    1978-01-01

    Development efforts are reported in detail for: (1) a lightweight solar array system for solar electric propulsion; (2) a high efficiency thin silicon solar cell; (3) conceptual design of 200 W/kg solar arrays; (4) fluorocarbon encapsulation for silicon solar cell array; and (5) technology assessment of concentrator solar arrays.

  14. STOCHASTICITY AND PERSISTENCE OF SOLAR CORONAL MASS EJECTIONS

    SciTech Connect

    Telloni, D.; Antonucci, E.; Carbone, V.; Lepreti, F.

    2014-01-20

    The study of the statistical properties of coronal mass ejections (CMEs) reveals that their properties depend on the period of solar activity. In particular, when investigating the origin of the waiting time distribution between CMEs, a significant departure from a Poisson process during periods of high solar activity has been found, thus suggesting the existence of at least two physical processes underlying the origin of CMEs. One acts continuously, perhaps related to randomly occurring magnetic reconfigurations of the solar corona at large scales. The other plays a role only during the solar maximum, probably due to the photospheric emergence of magnetic flux as a statistically persistent mechanism, which generates long correlation times among CME events strong enough not to be destroyed by the former random process.

  15. MAGNETIC FIELD STRUCTURES TRIGGERING SOLAR FLARES AND CORONAL MASS EJECTIONS

    SciTech Connect

    Kusano, K.; Bamba, Y.; Yamamoto, T. T.; Iida, Y.; Toriumi, S.; Asai, A.

    2012-11-20

    Solar flares and coronal mass ejections, the most catastrophic eruptions in our solar system, have been known to affect terrestrial environments and infrastructure. However, because their triggering mechanism is still not sufficiently understood, our capacity to predict the occurrence of solar eruptions and to forecast space weather is substantially hindered. Even though various models have been proposed to determine the onset of solar eruptions, the types of magnetic structures capable of triggering these eruptions are still unclear. In this study, we solved this problem by systematically surveying the nonlinear dynamics caused by a wide variety of magnetic structures in terms of three-dimensional magnetohydrodynamic simulations. As a result, we determined that two different types of small magnetic structures favor the onset of solar eruptions. These structures, which should appear near the magnetic polarity inversion line (PIL), include magnetic fluxes reversed to the potential component or the nonpotential component of major field on the PIL. In addition, we analyzed two large flares, the X-class flare on 2006 December 13 and the M-class flare on 2011 February 13, using imaging data provided by the Hinode satellite, and we demonstrated that they conform to the simulation predictions. These results suggest that forecasting of solar eruptions is possible with sophisticated observation of a solar magnetic field, although the lead time must be limited by the timescale of changes in the small magnetic structures.

  16. Coronal mass ejections and solar wind mass fluxes over the heliosphere during solar cycles 23 and 24 (1996-2014)

    NASA Astrophysics Data System (ADS)

    Lamy, P.; Floyd, O.; Quémerais, E.; Boclet, B.; Ferron, S.

    2017-01-01

    Coronal mass ejections (CMEs) play a major role in the heliosphere, and their contribution to the solar wind mass flux, already considered in the Skylab and Solwind eras with conflicting results, is reexamined in the light of 19 years (1996-2014) of SOHO observations with the Large Angle and Spectroscopic Coronagraph (LASCO-C2) for the CMEs and extended for the first time to all latitudes thanks to the whole-heliosphere data from the Solar Wind ANisotropies (SWAN) instrument supplemented by in situ data aggregated in the OMNI database. First, several mass estimates reported in the ARTEMIS (Automated Recognition of Transient Events and Marseille Inventory from Synoptic maps) catalog of LASCO CMEs are compared with determinations based on the combined observations with the twin STEREO/Sun Earth Connection Coronal and Heliospheric Investigation coronagraphs in order to ascertain their validity. A simple geometric model of the CMEs is introduced to generate Carrington maps of their mass flux and then to produce annualized synoptic maps. The Lyman α SWAN data are inverted to similarly produce synoptic maps to be compared with those of the CME flux. The ratio of the annualized CME to solar wind mass flux is found to closely track the solar cycle over the heliosphere. In the near-ecliptic region and at latitudes up to ˜55°, this ratio was negligibly small during the solar minima of cycles 22/23 and 23/24 and rose to 6% and 5%, respectively, at the maximum of solar cycles 23 and 24. These maximum ratios increased at higher latitudes, but this result is likely biased by the inherent limitation of determining the true latitude of CMEs.

  17. Solar cycle dependence of Wind/EPACT protons, solar flares and coronal mass ejections

    NASA Astrophysics Data System (ADS)

    Miteva, R.; Samwel, S. W.; Costa-Duarte, M. V.; Malandraki, O. E.

    2017-01-01

    The aim of this work is to compare the occurrence and overall properties of solar energetic particles (SEPs), solar flares and coronal mass ejections (CMEs) over the first seven years in solar cycles (SCs) 23 and 24. For the case of SEP events, we compiled a new proton event catalog using data from the Wind/EPACT instrument. We confirm the previously known reduction of high energy proton events in SC24 compared to the same period in SC23; our analysis shows a decrease of 25-50 MeV protons by about 30%. The similar trend is found for X to C-class solar flares which are less by about 40% and also for faster than 1000 km/s CMEs, which are reduced by about 45%. In contrast, slow CMEs are more numerous in the present solar cycle. We discuss the implications of these results for the population of SEP-productive flares and CMEs.

  18. INFLUENCE OF THE AMBIENT SOLAR WIND FLOW ON THE PROPAGATION BEHAVIOR OF INTERPLANETARY CORONAL MASS EJECTIONS

    SciTech Connect

    Temmer, Manuela; Rollett, Tanja; Moestl, Christian; Veronig, Astrid M.; Vrsnak, Bojan; Odstrcil, Dusan

    2011-12-20

    We study three coronal mass ejection (CME)/interplanetary coronal mass ejection (ICME) events (2008 June 1-6, 2009 February 13-18, and 2010 April 3-5) tracked from Sun to 1 AU in remote-sensing observations of Solar Terrestrial Relations Observatory Heliospheric Imagers and in situ plasma and magnetic field measurements. We focus on the ICME propagation in interplanetary (IP) space that is governed by two forces: the propelling Lorentz force and the drag force. We address the question: which heliospheric distance range does the drag become dominant and the CME adjust to the solar wind flow. To this end, we analyze speed differences between ICMEs and the ambient solar wind flow as a function of distance. The evolution of the ambient solar wind flow is derived from ENLIL three-dimensional MHD model runs using different solar wind models, namely, Wang-Sheeley-Arge and MHD-Around-A-Sphere. Comparing the measured CME kinematics with the solar wind models, we find that the CME speed becomes adjusted to the solar wind speed at very different heliospheric distances in the three events under study: from below 30 R{sub Sun }, to beyond 1 AU, depending on the CME and ambient solar wind characteristics. ENLIL can be used to derive important information about the overall structure of the background solar wind, providing more reliable results during times of low solar activity than during times of high solar activity. The results from this study enable us to obtain greater insight into the forces acting on CMEs over the IP space distance range, which is an important prerequisite for predicting their 1 AU transit times.

  19. Two ten-billion-solar-mass black holes at the centres of giant elliptical galaxies.

    PubMed

    McConnell, Nicholas J; Ma, Chung-Pei; Gebhardt, Karl; Wright, Shelley A; Murphy, Jeremy D; Lauer, Tod R; Graham, James R; Richstone, Douglas O

    2011-12-08

    Observational work conducted over the past few decades indicates that all massive galaxies have supermassive black holes at their centres. Although the luminosities and brightness fluctuations of quasars in the early Universe suggest that some were powered by black holes with masses greater than 10 billion solar masses, the remnants of these objects have not been found in the nearby Universe. The giant elliptical galaxy Messier 87 hosts the hitherto most massive known black hole, which has a mass of 6.3 billion solar masses. Here we report that NGC 3842, the brightest galaxy in a cluster at a distance from Earth of 98 megaparsecs, has a central black hole with a mass of 9.7 billion solar masses, and that a black hole of comparable or greater mass is present in NGC 4889, the brightest galaxy in the Coma cluster (at a distance of 103 megaparsecs). These two black holes are significantly more massive than predicted by linearly extrapolating the widely used correlations between black-hole mass and the stellar velocity dispersion or bulge luminosity of the host galaxy. Although these correlations remain useful for predicting black-hole masses in less massive elliptical galaxies, our measurements suggest that different evolutionary processes influence the growth of the largest galaxies and their black holes.

  20. Mass fractionation of the lunar surface by solar wind sputtering

    NASA Technical Reports Server (NTRS)

    Switkowski, Z. E.; Haff, P. K.; Tombrello, T. A.; Burnett, D. S.

    1977-01-01

    An investigation is conducted concerning the mass-fractionation effects produced in connection with the bombardment of the moon by the solar wind. Most of the material ejected by sputtering escapes the moon's gravity, but some returning matter settles back onto the lunar surface. This material, which is somewhat richer in heavier atoms than the starting surface, is incorporated into the heavily radiation-damaged outer surfaces of grains. The investigation indicates that sputtering of the lunar surface by the solar wind will give rise to significant surface heavy atom enrichments if the grain surfaces are allowed to come into sputtering equilibrium.

  1. Coronal Mass Ejections and Solar Radio Emissions

    NASA Technical Reports Server (NTRS)

    Gopalswamy, Nat

    2010-01-01

    Coronal mass ejections (CMEs) have important connections to various types of radio emissions from the Sun. The persistent noise storm radiation (type I storm at metric wavelengths, type III storms at longer wavelengths) can be clearly interrupted by the occurrence of a CME in the active region that produces the storm. Sometimes the noise storm completely disappears and other times, it reappears in the active region. Long-lasting type III bursts are associated with CME eruption, thought to be due to the reconnection process taking place beneath the erupting CME. Type II bursts are indicative of electron acceleration in the CME-driven shocks and hence considered to be the direct response of the CME propagation in the corona and interplanetary medium. Finally type IV bursts indicate large-scale post-eruption arcades containing trapped electrons that produce radio emission. This paper summarizes some key results that connect CMEs to various types of radio emission and what we can learn about particle acceleration in the corona) and interplanetary medium. Particular emphasis will be placed on type If bursts because of their connection to interplanetary shocks detected in situ.

  2. Discovery of a 12 billion solar mass black hole at redshift 6.3 and its challenge to the black hole/galaxy co-evolution at cosmic dawn

    NASA Astrophysics Data System (ADS)

    Wu, Xue-Bing; Wang, Feige; Fan, Xiaohui; Yi, Weimin; Zuo, Wenwen; Bian, Fuyan; Jiang, Linhua; McGreer, Ian; Wang, Ran; Yang, Jinyi; Yang, Qian; Thompson, David; Beletsky, Yuri

    2015-08-01

    To date about 40 quasars with redshifts z>6 have been discovered. Each quasar harbors a black hole with a mass of about one billion solar masses. The existence of such black holes when the Universe was less than one billion years after the Big Bang presents significant challenges to theories of the formation and growth of black holes and the black hole/galaxy co-evolution. I will report a recent discovery of an ultra-luminous quasar at redshift z=6.30, which has an observed optical and near-infrared luminosity a few times greater than those of previously known z>6 quasars. With near-infrared spectroscopy, we obtain a black hole mass of about 12 billion solar masses, which is well consistent with the mass derived by assuming an Eddington-limited accretion. This ultra-luminous quasar with a 12 billion solar mass black hole at z>6 provides a unique laboratory to the study of the mass assembly and galaxy formation around the most massive black holes in the early Universe. It raises further challenges to the black hole/galaxy co-evolution in the epoch of cosmic reionization because the black hole needs to grow much faster than the host galaxy.

  3. Negative C3 Launch Options for Solar System Exploration

    NASA Technical Reports Server (NTRS)

    Leifer, S.; Noca, M.

    1998-01-01

    Low thrust trajectory analyses were used to examine the feasibility of using solar electronic propulsion for Earth escape from a negative C3 launch for deep space missions in order to significantly increase the net delivered mass capability of inexpensive launch vehicles.

  4. High-Altitude Air Mass Zero Calibration of Solar Cells

    NASA Technical Reports Server (NTRS)

    Woodyard, James R.; Snyder, David B.

    2005-01-01

    Air mass zero calibration of solar cells has been carried out for several years by NASA Glenn Research Center using a Lear-25 aircraft and Langley plots. The calibration flights are carried out during early fall and late winter when the tropopause is at the lowest altitude. Measurements are made starting at about 50,000 feet and continue down to the tropopause. A joint NASA/Wayne State University program called Suntracker is underway to explore the use of weather balloon and communication technologies to characterize solar cells at elevations up to about 100 kft. The balloon flights are low-cost and can be carried out any time of the year. AMO solar cell characterization employing the mountaintop, aircraft and balloon methods are reviewed. Results of cell characterization with the Suntracker are reported and compared with the NASA Glenn Research Center aircraft method.

  5. Solar Radio Emission as a Prediction Technique for Coronal Mass Ejections' registration

    NASA Astrophysics Data System (ADS)

    Sheiner, Olga; Fridman, Vladimir

    2016-07-01

    The concept of solar Coronal Mass Ejections (CMEs) as global phenomenon of solar activity caused by the global magnetohydrodynamic processes is considered commonly accepted. These processes occur in different ranges of emission, primarily in the optical and the microwave emission being generated near the surface of the sun from a total of several thousand kilometers. The usage of radio-astronomical data for CMEs prediction is convenient and promising. Actually, spectral measurements of solar radio emission cover all heights of solar atmosphere, sensitivity and accuracy of measurements make it possible to record even small energy changes. Registration of the radio emission is provided by virtually all-weather ground-based observations, and there is the relative cheapness to obtain the corresponding information due to a developed system of monitoring observations. On the large statistical material there are established regularities of the existence of sporadic radio emission at the initial stage of CMEs' formation and propagation in the lower layers of the solar atmosphere during the time interval from 2-3 days to 2 hours before registration of CMEs on coronagraph. In this report we present the prediction algorithm and scheme of short-term forecasting developed on the base of statistical analysis regularities of solar radio emission data prior to "isolated" solar Coronal Mass Ejections registered in 1998, 2003, 2009-2013.

  6. On the deficit problem of mass and energy of solar coronal mass ejections connected with interplanetary shocks

    NASA Technical Reports Server (NTRS)

    Ivanchuk, V. I.; Pishkalo, N. I.

    1995-01-01

    Mean values of a number of parameters of the most powerful coronal mass ejections (CMEs) and interplanetary shocks generated by these ejections are estimated using an analysis of data obtained by the cosmic coronagraphs and spacecrafts, and geomagnetic storm measurements. It was payed attention that the shock mass and mechanical energy, averaging 5 x 10(exp 16) grm and 2 x 10(exp 32) erg respectively, are nearly 10 times larger than corresponding parameters of the ejections. So, the CME energy deficit problem seems to exist really. To solve this problem one can make an assumption that the process of the mass and energy growth of CMEs during their propagation out of the Sun observed in the solar corona is continued in supercorona too up to distances of 10-30 solar radii. This assumption is confirmed by the data analysis of five events observed using zodiacal light photometers of the HELIOS- I and HELIOS-2 spacecrafts. The mass growth rate is estimated to be equal to (1-7) x 10(exp 11) grm/sec. It is concluded that the CME contribution to mass and energy flows in the solar winds probably, is larger enough than the value of 3-5% adopted usually.

  7. The 1991 Solar World Congress: Proceedings of the Biennial Congress of the International Solar Energy Society, volume 3, part 1

    NASA Astrophysics Data System (ADS)

    Arden, M. E.; Burley, Susan M. A.; Coleman, Martha

    Proceedings of the 1991 Solar World Congress, volume 3, part 1 are presented. Topics covered include: solar building design; zero-energy building designs; emerging architecture; vernacular architecture; passive commercial buildings; daylighting; atriums; passive strategies and materials; transparent insulation; convection and mass; comfort; passive cooling; and passive computer analysis.

  8. Reconnection in the lower solar atmosphere and coronal mass ejections

    NASA Astrophysics Data System (ADS)

    Wang, Jingxiu

    2006-01-01

    In 1985, a phenomenon in the solar photosphere, called magnetic flux cancellation, was first described in detail by Livi et al. (1985) [The cancellation of magnetic flux. I On the quiet sun, Aust. J. Phys. 38, 855 873, 1985] and Martin et al. (1985) [The cancellation of magnetic flux. II In a decaying active region, Aust. J. Phys. 38, 929 959, 1985]. Since then, it has been revealed that flux cancellation is intrinsically correlated to most, if not all, types of solar activity, such as flare, filament formation and eruption, and ubiquitous small-scale activity, e.g., X-ray bright point, explosive event, mini-filament eruption and so on. Only recently, it was discovered that flux cancellation appeared to be a key part of magnetic evolution leading to the initiation of coronal mass ejections (CMEs) [Zhang et al., Magnetic flux cancellation associated withthe major solar event on 2000 July 14. Astrophys. J. 548, L99 102, 2001; Zhang et al., 2001b. Filament-associated halo coronal mass ejection, Chin. J. Astron. Astrophys., 1, 85 98, 2001; Zhang and Wang, Filament eruptions and halo coronal mass ejections, Astrophys. J. 554, 474 487, 2001]. On the other hand, the nature of flux cancellation has been a topic of persistent interest and debate. We review the observational properties of magnetic flux cancellation and the relevant theoretical studies, describe the vector magnetic field changes in flux cancellation in CME-associated active regions (ARs), and demonstrate that the well-observed flux cancellations fit nicely the scenario of magnetic reconnection in the lower solar atmosphere. It is suggested that magnetic reconnection in the lower solar atmosphere is a ubiquitous process on the Sun. It is a key element in the magnetic evolution of CMEs.

  9. Formation of the low-mass solar nebula

    NASA Technical Reports Server (NTRS)

    Ruzmaikina, T. V.; Khatuncev, I. V.; Konkina, T. V.

    1993-01-01

    We study an accretional stage of the formation and early evolution of the solar nebula with relatively small angular momentum. We investigate the evolution of the disk and its vertical structure, particularly the shock front between disk and infalling material. Calculations start at a moment when a low-mass star-like core surrounded by small embryo disk have been formed at the center of the presolar nebula and the bulk of mass remained in the envelope. The forming solar nebula is approximated as a thin viscous disk surrounded by accreting envelope. The distribution of temperature in the infalling envelope is determined by solving spherically symmetric equations of radiative transfer. As the energy source, we take into account all energy released within the centrifugal radius of the infalling matter. Other aspects of this study are discussed.

  10. Mass fractionation of the lunar surface by solar wind sputtering

    NASA Technical Reports Server (NTRS)

    Switkowski, Z. E.; Haff, P. K.; Tombrello, T. A.; Burnett, D. S.

    1975-01-01

    The sputtering of the lunar surface by the solar wind is examined as a possible mechanism of mass fractionation. Simple arguments based on current theories of sputtering and the ballistics of the sputtered atoms suggest that most ejected atoms will have sufficiently high energy to escape lunar gravity. However, the fraction of atoms which falls back to the surface is enriched in the heavier atomic components relative to the lighter ones. This material is incorporated into the heavily radiation-damaged outer surfaces of grains where it is subject to resputtering. Over the course of several hundred years an equilibrium surface layer, enriched in heavier atoms, is found to form. The dependence of the calculated results upon the sputtering rate and on the details of the energy spectrum of sputtered particles is investigated. It is concluded that mass fractionation by solar wind sputtering is likely to be an important phenomenon on the lunar surface.

  11. Solar energetic proton events and coronal mass ejections near solar minimum

    NASA Technical Reports Server (NTRS)

    Kahler, S. W.; Cliver, E. W.; Cane, H. V.; Mcguire, R. E.; Reames, D. V.; Sheeley, N. R., Jr.; Howard, R. A.

    1987-01-01

    We have examined the association of coronal mass ejections (CME's) with solar energetic (9-23 MeV) proton (SEP) events during the 1983-1985 approach to solar minimum. Twenty-two of 25 SEP events were associated with CME's, a result comparable to that previously found for the period 1979-1982 around solar maximum. Peak SEP fluxes were correlated with CME speeds but not with CME angular sizes. In addition, many associated CME's lay well out of the ecliptic plane. In a reverse study using all west hemisphere CME's of speeds exceeding 800 km/s and covering the period 1979-1985, we found that 29 of 31 events originating on the solar disk or limb were associated with observed SEP's. However, in contrast to the previous study, we found no cases of SEP events associated with magnetically well connected flares of short duration that lacked CME's.

  12. Axisymmetric Ab Initio Core-Collapse Supernova Simulations of 12--25 Solar Mass Stars

    SciTech Connect

    Bruenn, S. W.; Mezzacappa, Anthony; Hix, William Raphael; Lentz, E. J.; Messer, Bronson; Lingerfelt, Eric J; Blondin, J. M.; Endeve, Eirik; Marronetti, Pedro; Yakunin, Konstantin

    2013-01-01

    We present an overview of four ab initio axisymmetric core-collapse supernova simulations employing detailed spectral neutrino transport computed with our CHIMERA code and initiated from Woosley & Heger (2007) progenitors of mass 12, 15, 20, and 25 M_sun. All four models exhibit shock revival over ~ 200 ms (leading to the possibility of explosion), driven by neutrino energy deposition. Hydrodynamic instabilities that impart substantial asymmetries to the shock aid these revivals, with convection appearing first in the 12 solar mass model and the standing accretion shock instability (SASI) appearing first in the 25 solar mass model. Three of the models have developed pronounced prolate morphologies (the 20 solar mass model has remained approximately spherical). By 500 ms after bounce the mean shock radii in all four models exceed 3,000 km and the diagnostic explosion energies are 0.33, 0.66, 0.65, and 0.70 Bethe (B=10^{51} ergs) for the 12, 15, 20, and 25 solar mass models, respectively, and are increasing. The three least massive of our models are already sufficiently energetic to completely unbind the envelopes of their progenitors (i.e., to explode), as evidenced by our best estimate of their explosion energies, which first become positive at 320, 380, and 440 ms after bounce. By 850 ms the 12 solar mass diagnostic explosion energy has saturated at 0.38 B, and our estimate for the final kinetic energy of the ejecta is ~ 0.3 B, which is comparable to observations for lower-mass progenitors.

  13. Mass flow velocity distribution in the solar chromosphere

    NASA Technical Reports Server (NTRS)

    Tripp, D. A.

    1981-01-01

    A study of chromospheric lines (those of Si-II and Si-III) was made using the data from high resolution telescope and spectrograph (HRTS). The optically thick line profiles such as lambda 1206 due to Si-III and lambda 1265 and lambda 1533 due to Si-II were to be investigated in detail using the techniques of spectrum synthesis in an attempt to model the mass flow velocity distribution in the region of the solar atmosphere.

  14. Solar cycle variation of some mass dependent characteristics of upflowing beams of terrestrial ions

    NASA Technical Reports Server (NTRS)

    Collin, H. L.; Peterson, W. K.; Shelley, E. G.

    1987-01-01

    Examination of the S3-3 and DE ion composition data spread over a solar cycle indicates that some characteristics of energetic upflowing terrestrial ion beams above the auroral zone show dependence on solar cycle. At solar maximum the different ion beam mass components have comparable mean energies, and O(+) dominates the beam composition. The ion energies are consistent with having been acquired from the potential drop below the satellite inferred from the electron loss cone distributions. At solar minimum the beam composition is dominated by H(+), but the O(+) has a higher mean energy and is hotter than the H(+) component. Also, the O(+) has more energy than it could itself have acquired from the potential drop. These observations are qualitatively consistent with the ion beams having acquired their energies from a parallel electric field and being partially thermalized through the two-stream instability between the two ion species, with this effect being modulated by the beam composition.

  15. Early solar mass loss, opacity uncertainties, and the solar abundance problem

    SciTech Connect

    Guzik, Joyce Ann; Keady, John; Kilcrease, David

    2009-01-01

    Solar models calibrated with the new element abundance mixture of Asplund et al. published in 2005 no longer produce good agreement with the sound speed, convection zone depth, and convection zone helium abundance inferred from solar oscillation data. Attempts to modify the input physics of the standard model, for example, by including enhanced diffusion, increased opacities, accretion, convective overshoot, or gravity waves have not restored the good agreement attained with the prior abundances. Here we present new models including early mass loss via a stronger solar wind. Early mass loss has been investigated prior to the solar abundance problem to deplete lithium and resolve the 'faint early sun problem'. We find that mass loss modifies the core structure and deepens the convection zone, and so improves agreement with oscillation data using the new abundances: however the amount of mass loss must be small to avoid destroying all of the surface lithium, and agreement is not fully restored. We also considered the prospects for increasing solar interior opacities. In order to increase mixture opacities by the 30% required to mitigate the abundance problem, the opacities of individual elements (e.g., O, N, C, and Fe) must be revised by a factor of two to three for solar interior conditions: we are investigating the possibility of broader calculated line wings for bound-bound transitions at the relevant temperatures to enhance opacity. We find that including all of the elements in the AGS05 opacity mixture (through uranium at atomic number Z=92) instead of only the 17 elements in the OPAL opacity mixture increases opacities by a negligible 0.2%.

  16. Early Solar Mass Loss, Opacity Uncertainties, and the Solar Abundance Problem

    NASA Astrophysics Data System (ADS)

    Guzik, Joyce Ann; Keady, J. J.; Kilcrease, D. P.

    2009-09-01

    Solar models calibrated with the new element abundance mixture of Asplund et al. published in 2005 no longer produce good agreement with the sound speed, convection zone depth, and convection zone helium abundance inferred from solar oscillation data. Attempts to modify the input physics of the standard model, for example, by including enhanced diffusion, increased opacities, accretion, convective overshoot, or gravity waves have not restored the good agreement attained with the prior abundances. Here we present new models including early mass loss via a stronger solar wind. Early mass loss has been investigated prior to the solar abundance problem to deplete lithium and resolve the `faint early sun problem'. We find that mass loss modifies the core structure and deepens the convection zone, and so improves agreement with oscillation data using the new abundances; however the amount of mass loss must be small to avoid destroying all of the surface lithium, and agreement is not fully restored. We also considered the prospects for increasing solar interior opacities. In order to increase mixture opacities by the 30% required to mitigate the abundance problem, the opacities of individual elements (e.g., O, N, C, and Fe) must be revised by a factor of two to three for solar interior conditions; we are investigating the possibility of broader calculated line wings for bound-bound transitions at the relevant temperatures to enhance opacity. We find that including all of the elements in the AGS05 opacity mixture (through uranium at atomic number Z = 92) instead of only the 17 elements in the OPAL opacity mixture increases opacities by a negligible 0.2%.

  17. Dynamical limits on dark mass in the outer solar system

    SciTech Connect

    Hogg, D.W.; Quinlan, G.D.; Tremaine, S. MIT, Cambridge, MA )

    1991-06-01

    Simplified model solar systems with known observational errors are considered in conducting a dynamical search for dark mass and its minimum detectable amount, and in determining the significance of observed anomalies. The numerical analysis of the dynamical influence of dark mass on the orbits of outer planets and comets is presented in detail. Most conclusions presented are based on observations of the four giant planets where the observational errors in latitude and longitude are independent Gaussian variables with a standard deviation. Neptune's long orbital period cannot be predicted by modern ephemerides, and no evidence of dark mass is found in considering this planet. Studying the improvement in fit when observations are fitted to models that consider dark mass is found to be an efficient way to detect dark mass. Planet X must have a mass of more than about 10 times the minimum detectable mass to locate the hypothetical planet. It is suggested that the IRAS survey would have already located the Planet X if it is so massive and close that it dynamically influences the outer planets. Orbital residuals from comets are found to be more effective than those from planets in detecting the Kuiper belt. 35 refs.

  18. Tracking Nonradial Motions and Azimuthal Expansions of Interplanetary CMEs with the Solar Mass Ejection Imager

    SciTech Connect

    Kahler, Stephen

    2010-03-25

    The trajectories of interplanetary CMEs (ICMEs) are modified by their interactions with solar wind streams. These interactions can result in non-radial deflections of ICME trajectories and changes to their rates of azimuthal expansion. The Solar Mass Ejection Imager (SMEI), launched earlier in 2003 January, has provided heliospheric images of several hundred ICMEs during the declining portion of solar cycle 23. We selected three SMEI ICMEs, each traversing a range of solar elongation angles epsilon>20 deg. , and measured the time changes of their leading-edge profiles plotted against position angle, PA. The parabolic fits to those profiles yielded the propagation directions of the ICMEs as well as their leading-edge curvatures and time profiles. The selected ICMEs were associated with LASCO CMEs, so we tracked the PA variations in their propagation over 1 to 3-day periods. We found good fits for two of the ICMEs, but one yielded generally poor fits.

  19. C3-class Solar Flare Eruption

    NASA Video Gallery

    Just as sunspot 1105 was turning away from Earth on Sept. 8, the active region erupted, producing a C3-class solar flare (peak @ 2330 UT) and a fantastic prominence. This is a three color closeup o...

  20. Energetic Correlation Between Solar Flares and Coronal Mass Ejections

    NASA Technical Reports Server (NTRS)

    Dennis, Brian R.; Medlin, Drew A.; Haga, Leah; Schwartz, Richard a.; Tolbert, A. Kimberly

    2007-01-01

    We find a strong correlation between the kinetic energies (KEs) of the coronal mass ejections (CMEs) and the radiated energies of the associated solar flares for the events that occurred during the period of intense solar activity between 18 October and 08 November 2003. CME start times, speeds, mass and KEs were taken from Gopalswamy et al. (2005), who used SOHO/LASCO observations. The GOES observations of the associated flares were analyzed to find the peak soft X-ray (SXR) flux, the radiated energy in SXRs (L(sub sxR)), and the radiated energy from the emitting plasma across all wavelengths (L(sub hot)). RHESSI observations were also used to find the energy in non-thermal electrons, ions, and the plasma thermal energy for some events. For two events, SORCE/TIM observations of the total solar irradiance during a flare were also available to give the total radiated flare energy (L(sub total)).W e find that the total flare energies of the larger events are of the same order of magnitude as the CME KE with a stronger correlation than has been found in the past for other time intervals.

  1. Prompt solar proton events and coronal mass ejections

    NASA Technical Reports Server (NTRS)

    Kahler, S. W.; Hildner, E.; Van Hollebeke, M. A. I.

    1978-01-01

    Data from the HAO white-light coronagraph and the X-ray telescope on Skylab have been used to investigate the coronal manifestations of 18 prompt solar proton events observed on the IMP 7 spacecraft during the Skylab period. Evidence is found that a mass-ejection event is a necessary condition for the occurrence of a prompt proton event. Mass-ejection events can be observed directly in the white-light coronagraph when they occur near the limb and inferred from the presence of a long-decay X-ray event when they occur on the disk. It is suggested that: (1) the occurrence of mass-ejection events facilitates the escape of protons - whether accelerated at low or high altitudes - to the interplanetary medium; and (2) there may exist a proton acceleration region above or around the outward moving ejecta far above the flare site.

  2. Mass and heat transfer model of Tubular Solar Still

    SciTech Connect

    Ahsan, Amimul; Fukuhara, Teruyuki

    2010-07-15

    In this paper, a new mass and heat transfer model of a Tubular Solar Still (TSS) was proposed incorporating various mass and heat transfer coefficients taking account of the humid air properties inside the still. The heat balance of the humid air and the mass balance of the water vapor in the humid air were formulized for the first time. As a result, the proposed model enabled to calculate the diurnal variations of the temperature, water vapor density and relative humidity of the humid air, and to predict the hourly condensation flux besides the temperatures of the water, cover and trough, and the hourly evaporation flux. The validity of the proposed model was verified using the field experimental results carried out in Fukui, Japan and Muscat, Oman in 2008. The diurnal variations of the calculated temperatures and water vapor densities had a good agreement with the observed ones. Furthermore, the proposed model can predict the daily and hourly production flux precisely. (author)

  3. A Historic View of Solar Coronal Mass Ejections (CMEs)

    NASA Technical Reports Server (NTRS)

    SaintCyr, Orville C.

    2010-01-01

    We present a historic overview of CME observations, ending with concepts for future measurement capabilities. One of the first detections of what we now call a CME was provided by instrumentation on OSO-7 and reported by Tousey (1973); but the phrase "corona) mass ejection" was coined after the Skylab/ATM coronagraph detected dozens of the transients over its nine month observing run (e.g., Munro et al., 1979). Pre-discovery identification of likely CMEs were then reported in historic eclipse photographs and drawings (e.g., Eddy, 1974; Cliver, 1989). Multi-year observations followed with groundbased MLSO MK3/4 coronagraph (1980-present), and spacebased missions: Solwind (1979-1985), SMM (1980-1989), SOHO LASCO/EIT (1996-present), SMEI (2003-present), and STEREO SECCHI (2006-present). The Spartan 201 coronagraph flew in space multiple times. The influential Gosling (1993) "solar flare myth" manuscript identified CMEs as the cause of the most severe geomagnetic storms, thus cementing their importance in Sun-Earth connection studies. A new window into CMEs was opened with the launch of SOHO in 1995 when the UVCS spectrometer began returning plasma diagnostics of a significant number of events (e.g., Ciaravella et al., 2006). What about the future for CME research? Statistical properties of the UVCS CME observations are forthcoming; the STEREO mission should continue to return views of CMEs from unique vantage points; and the recent launch of SDO should provide new insights into the small spatial scale dynamics of activity associated with CMEs. Several new observing techniques have been demonstrated at total eclipses, and inclusion on spacebased platforms in the future could also prove valuable for understanding CMEs. A common element of several recent proposals is to image the white-light corona with extremely high spatial resolution. The momentary glimpses of the corona during total solar eclipses have shown fine structure that is not captured by global models, and

  4. The Fraction of Interplanetary Coronal Mass Ejections That Are Magnetic Clouds: Evidence for a Solar Cycle Variation

    NASA Technical Reports Server (NTRS)

    Richardson, I. G.; Cane, H. V.

    2004-01-01

    "Magnetic clouds" (MCs) are a subset of interplanetary coronal mass ejections (ICMEs) characterized by enhanced magnetic fields with an organized rotation in direction, and low plasma beta. Though intensely studied, MCs only constitute a fraction of all the ICMEs that are detected in the solar wind. A comprehensive survey of ICMEs in the near- Earth solar wind during the ascending, maximum and early declining phases of solar cycle 23 in 1996 - 2003 shows that the MC fraction varies with the phase of the solar cycle, from approximately 100% (though with low statistics) at solar minimum to approximately 15% at solar maximum. A similar trend is evident in near-Earth observations during solar cycles 20 - 21, while Helios 1/2 spacecraft observations at 0.3 - 1.0 AU show a weaker trend and larger MC fraction.

  5. AN IMPROVEMENT ON MASS CALCULATIONS OF SOLAR CORONAL MASS EJECTIONS VIA POLARIMETRIC RECONSTRUCTION

    SciTech Connect

    Dai, Xinghua; Wang, Huaning; Huang, Xin; Du, Zhanle; He, Han

    2015-03-01

    The mass of a coronal mass ejection (CME) is calculated from the measured brightness and assumed geometry of Thomson scattering. The simplest geometry for mass calculations is to assume that all of the electrons are in the plane of the sky (POS). With additional information like source region or multiviewpoint observations, the mass can be calculated more precisely under the assumption that the entire CME is in a plane defined by its trajectory. Polarization measurements provide information on the average angle of the CME electrons along the line of sight of each CCD pixel from the POS, and this can further improve the mass calculations as discussed here. A CME event initiating on 2012 July 23 at 2:20 UT observed by the Solar Terrestrial Relations Observatory is employed to validate our method.

  6. Associations between coronal mass ejections and solar energetic proton events

    NASA Technical Reports Server (NTRS)

    Kahler, S. W.; Sheeley, N. R., Jr.; Howard, R. A.; Michels, D. J.; Koomen, M. J.; Mcguire, R. E.; Von Rosenvinge, T. T.; Reames, D. V.

    1984-01-01

    A comparison between proton events and coronal mass ejections (CMEs) based on nearly three years of observations around the recent maximum of solar activity is presented. Peak proton fluxes are found to correlate with both the speeds and the angular sizes of the associated CMEs. It is shown that CME speeds do not significantly correlate with CME angular sizes, so that peak proton fluxes are correlated with two independent CME parameters. With larger angular sizes, CMEs are more likely to be loops and fans rather than jets and spikes and are more likely to intersect the ecliptic.

  7. Studying Geoeffective Interplanetary Coronal Mass Ejections Between the Sun and Earth: Space Weather Implications of Solar Mass Ejection Imager Observations

    DTIC Science & Technology

    2009-05-14

    during the Mav 12th, 1997 ICME, /. Ahnos. Sol. Terr. Phys., 66, 1295-1309. Billings, D. E. (1966), A Guide to the Solar Corona , Academic, San Diego...SUBTITLE Studying geoeffective interplanetary coronal mass ejections Between the Sun and Earth: Space weather implications of Solar Mass Ejection...DISTRIBUTION . „ . ru^en.1 nomicmcni Approved for Public Release; Distribution Unlimited. *Boston College, Chestnut Hill, MA, **AFRL, National Solar Ob

  8. Physical properties and evolutionary time scales of disks around solar-type and intermediate mass stars

    NASA Technical Reports Server (NTRS)

    Strom, Stephen E.; Edwards, Suzan

    1993-01-01

    Recent observations of circumstellar disks and their evolutionary timescales are reviewed. It is concluded that disks appear to be a natural outcome of the star-formation process. The disks surrounding young stars initially are massive, with optically thick structures comprised of gas and micron-sized grains. Disk masses are found to range from 0.01 to 0.2 solar masses for solar-type PMS stars, and from 0.01 to 6 solar masses for young, intermediate mass stars. Massive, optically thick accretion disks have accretion rates between 10 exp -8 and 10 exp -6 solar masses/yr for solar type PMS stars and between 10 exp -6 and 10 exp -4 solar masses/yr for intermediate stars. The results suggest that a significant fraction of the mass comprising the star may have passed through a circumstellar accretion disk.

  9. Investigation of the Large Scale Evolution and Topology of Coronal Mass Ejections in the Solar Wind

    NASA Technical Reports Server (NTRS)

    Riley, Peter

    1999-01-01

    This investigation is concerned with the large-scale evolution and topology of Coronal Mass Ejections (CMEs) in the solar wind. During this reporting period we have analyzed a series of low density intervals in the ACE (Advanced Composition Explorer) plasma data set that bear many similarities to CMEs. We have begun a series of 3D, MHD (Magnetohydrodynamics) coronal models to probe potential causes of these events. We also edited two manuscripts concerning the properties of CMEs in the solar wind. One was re-submitted to the Journal of Geophysical Research.

  10. The distribution of mass and angular momentum in the solar system

    SciTech Connect

    Marochnik, L.S.; Mukhin, L.M.; Sagdeev, R.Z. )

    1989-01-01

    This book describes the contribution of the comets in the Oort cloud to the angular momentum of the solar system. Topics covered include: Nuclear mass of the new comets observed, Mass of the Oort cloud, Mass distribution in the solar system, Zone of comet formation, Angular momentum of the Oort cloud, and Angular momentum of the Hills cloud.

  11. Three-dimensional global MHD modeling of a coronal mass ejection interacting with the solar wind

    NASA Astrophysics Data System (ADS)

    An, J.; Inoue, S.; Magara, T.; Lee, H.; Kang, J.; Hayashi, K.; Tanaka, T.; Den, M.

    2013-12-01

    We developed a three-dimensional (3D) magnetohydrodynamic (MHD) code to reproduce the structure of the solar wind, the propagation of a coronal mass ejection (CME), and the interaction between them. This MHD code is based on the finite volume method and total diminishing (TVD) scheme with an unstructured grid system. In particular, this grid system can avoid the singularity at the north and south poles and relax tight CFL conditions around the poles, both of which would arise in the spherical coordinate system (Tanaka 1995). In this study, we constructed a model of the solar wind driven by the physical values at 50 solar radii obtained from the MHD tomographic method (Hayashi et al. 2003) where an interplanetary scintillation (IPS) observational data is used. By comparing the result to the observational data obtained from the near-Earth OMNI dataset, we confirmed that our simulation reproduces the velocity, temperature and density profiles obtained from the near-Earth OMNI dataset. We then insert a spheromak-type CME (Kataoka et al. 2009) into our solar-wind model and investigate the propagation process of the CME interacting with the solar wind. In particular, we discuss how the magnetic twist accumulated in a CME affects the CME-solar wind interaction.

  12. Solar Energetic Particle Acceleration by a Shock Wave Accompanying a Coronal Mass Ejection in the Solar Atmosphere

    NASA Astrophysics Data System (ADS)

    Petukhova, A. S.; Petukhov, I. S.; Petukhov, S. I.; Ksenofontov, L. T.

    2017-02-01

    Solar energetic particle acceleration by a shock wave accompanying a coronal mass ejection (CME) is studied. The description of the accelerated particle spectrum evolution is based on the numerical calculation of the diffusive transport equation with a set of realistic parameters. The relation between the CME and shock speeds, which depend on the initial CME radius, is determined. Depending on the initial CME radius, its speed, and the magnetic energy of the scattering Alfvén waves, the accelerated particle spectrum is established 10–60 minutes from the beginning of CME motion. The maximum energies of particles reach 0.1–10 GeV. The CME radii of 3–5 {R}ȯ and the shock radii of 5–10 {R}ȯ agree with observations. The calculated particle spectra agree with the observed ones in events registered by ground-based detectors if the turbulence spectrum in the solar corona significantly differs from the Kolmogorov one.

  13. The structures, mass motions and footpoints of solar filaments

    NASA Astrophysics Data System (ADS)

    Venkataramanasastry, Aparna

    This thesis focuses on identifying the mechanism by which solar filaments acquire mass. Some of the speculations for how a filament gets its mass are 1) injection of mass from the chromosphere into the filament structure, and 2) condensation of mass from the corona into the region of the filament channel. Mass motion at the footpoints of the filaments is studied to detect mass entering and leaving the filament body. The magnetic properties of the footpoints of the filaments are also studied. Recommendations are drawn by comparing observational properties obtained in this study with the features used in some of the previously developed models. The datasets used for this study are high-resolution image sets of centerline and Doppler wings of Halpha, obtained using the Dutch Open Telescope (DOT). The data were obtained on Oct 30, 2010. The data set contains three filaments in an active region in the northern hemisphere of the Sun. The images in each wavelength are aligned and made into movies to find the footpoints of the filaments through which the mass goes into and comes out of the filaments from and to the chromosphere, respectively. The magnetic properties of the footpoints are studied by overlaying the magnetogram images with the DOT images by using full-disk Halpha images for matching the features in the two. Of the three filaments, one of the filaments is observed to be stable throughout the duration of the observations; another filament erupts after about two hours of the beginning of observations; and the third filament is in its early stages of formation. The ends of the stable filament are clearly observed whereas the ends of the erupting filament and the forming filament are observed clearly intermittently during the duration of the observations. The animations of the region near the ends of filament 1 reveal definite injection and draining of mass via the footpoints into and out of the filament. The mass motion into and out of the filaments are observed

  14. Rotational periods of solar-mass young stars in Orion

    NASA Astrophysics Data System (ADS)

    Marilli, E.; Frasca, A.; Covino, E.; Alcalá, J. M.; Catalano, S.; Fernández, M.; Arellano Ferro, A.; Rubio-Herrera, E.; Spezzi, L.

    2007-03-01

    Context: The evolution of the angular momentum in young low-mass stars is still a debated issue. The stars presented here were discovered as X-ray sources in the ROSAT All-Sky Survey (RASS) of the Orion complex and subsequently optically identified thanks to both low and high resolution spectroscopy. Aims: The determination of the rotational periods in young low-mass stars of different age is fundamental for the understanding of the angular momentum evolution. Methods: We performed a photometric monitoring program on a sample of 40 solar-mass young stars in the Orion star-forming region, almost all previously identified as weak T Tauri stars (WTTS) candidates. Photometric B and V data were collected from 1999 to 2006 at Catania Astrophysical Observatory (OAC). Data were also acquired in December 1998 at Calar Alto Observatory (CA) and in 1999, 2000, and 2003 at San Pedro Martir (SPM). From the observed rotational modulation, induced by starspots, we derived the rotation periods, using both the Lomb-Scargle periodogram and the CLEAN deconvolution algorithms. Results: In total, we were able to determine the rotation periods for 39 stars, spanning from about 0.5 to 13 days, showing a rather flat distribution with a peak around 1-2 days. Though some of these stars were found to be spectroscopic binaries, only the systems with shorter orbital periods and circular orbits turned out to be synchronized. In the other cases, the rotational period is shorter than the period of pseudo-synchronization at periastron. Conclusions: .The new data provide further evidence for the spin up of solar-mass stars predicted by models of angular momentum evolution of pre-main sequence (PMS) stars. Based on observations collected at the Catania Astrophysical Observatory (Italy), at the Estación de Observación de Calar Alto (Spain), and San Pedro Martir Observatory (México). Appendix A is only available in electronic form at http://www.aanda.org

  15. Optimization of solar cells for air mass zero operation and a study of solar cells at high temperatures, phase 2

    NASA Technical Reports Server (NTRS)

    Hovel, H.; Woodall, J. M.

    1976-01-01

    Crystal growth procedures, fabrication techniques, and theoretical analysis were developed in order to make GaAlAs-GaAs solar cell structures which exhibit high performance at air mass 0 illumination and high temperature conditions.

  16. Reduction of Martian Sample Return Mission Launch Mass with Solar Sail Propulsion

    NASA Technical Reports Server (NTRS)

    Russell, Tiffany E.; Heaton, Andrew; Thomas, Scott; Thomas, Dan; Young, Roy; Baysinger, Mike; Capizzo, Pete; Fabisinski, Leo; Hornsby, Linda; Maples, Dauphne; Miernik, Janie

    2013-01-01

    Solar sails have the potential to provide mass and cost savings for spacecraft traveling within the inner solar system. Companies like L'Garde have demonstrated sail manufacturability and various in-space deployment methods. The purpose of this study was to evaluate a current Mars sample return architecture and to determine how cost and mass would be reduced by incorporating a solar sail propulsion system. The team validated the design proposed by L'Garde, and scaled the design based on a trajectory analysis. Using the solar sail design reduced the required mass, eliminating one of the three launches required in the original architecture.

  17. Reduction of Martian Sample Return Mission Launch Mass with Solar Sail Propulsion

    NASA Technical Reports Server (NTRS)

    Russell, Tiffany E.; Heaton, Andy F.; Young, Roy; Baysinger, Mike; Schnell, Andrew R.

    2013-01-01

    Solar sails have the potential to provide mass and cost savings for spacecraft traveling within the innter solar system. Companies like L'Garde have demonstrated sail manufacturability and various i-space development methods. The purpose of this study was to evaluate a current Mars sample return architecture and to determine how cost and mass would be reduced by incorporating a solar sail propulsion system. The team validated the design proposed by L'Garde, and scaled the design based on a trajectory analysis. Using the solar sail design reduced the required mass, eliminating one of the three launches required in the original architecture.

  18. Evidence for a solar cause of the Pleistocene mass extinction.

    NASA Astrophysics Data System (ADS)

    Laviolette, Paul A.

    2011-06-01

    The hypothesis is presented that an abrupt rise in atmospheric radiocarbon concentration evident in the Cariaco Basin varve record at 12,837±10 cal yrs BP contemporaneous with the Rancholabrean termination, may have been produced by a super-sized solar proton event (SPE) having a fluence of ~1.3 X 10^11 protons/cm^2. A SPE of this magnitude would have been large enough to deliver a lethal radiation dose of at least 3 - 6 Sv to the Earth's surface, and hence could have been a principal cause of the final termination of the Pleistocene megafauna and several genera of smaller mammals and birds. The event time-correlates with a large magnitude acidity spike found at 1708.65 m in the GISP2 Greenland ice record, which is associated with high NO-3 ion concentrations and a rapid rise in 10^Be deposition rate, all of which are indicators of a sudden cosmic ray influx. The depletion of nitrate ion within this acidic ice layer suggests that the snowpack surface at that time was exposed to intense UV for a prolonged period which is consistent with a temporary destruction of the polar ozone layer by solar cosmic rays. The acidity event also coincides with a large magnitude, abrupt climatic excursion and is associated with elevated ammonium ion concentrations, an indicator of global fires.

  19. A mass of less than 15 solar masses for the black hole in an ultraluminous X-ray source.

    PubMed

    Motch, C; Pakull, M W; Soria, R; Grisé, F; Pietrzyński, G

    2014-10-09

    Most ultraluminous X-ray sources have a typical set of properties not seen in Galactic stellar-mass black holes. They have luminosities of more than 3 × 10(39) ergs per second, unusually soft X-ray components (with a typical temperature of less than about 0.3 kiloelectronvolts) and a characteristic downturn in their spectra above about 5 kiloelectronvolts. Such puzzling properties have been interpreted either as evidence of intermediate-mass black holes or as emission from stellar-mass black holes accreting above their Eddington limit, analogous to some Galactic black holes at peak luminosity. Recently, a very soft X-ray spectrum was observed in a rare and transient stellar-mass black hole. Here we report that the X-ray source P13 in the galaxy NGC 7793 is in a binary system with a period of about 64 days and exhibits all three canonical properties of ultraluminous sources. By modelling the strong optical and ultraviolet modulations arising from X-ray heating of the B9Ia donor star, we constrain the black hole mass to be less than 15 solar masses. Our results demonstrate that in P13, soft thermal emission and spectral curvature are indeed signatures of supercritical accretion. By analogy, ultraluminous X-ray sources with similar X-ray spectra and luminosities of up to a few times 10(40) ergs per second can be explained by supercritical accretion onto massive stellar-mass black holes.

  20. A SOLAR CORONAL JET EVENT TRIGGERS A CORONAL MASS EJECTION

    SciTech Connect

    Liu, Jiajia; Wang, Yuming; Shen, Chenglong; Liu, Kai; Pan, Zonghao; Wang, S.

    2015-11-10

    In this paper, we present multi-point, multi-wavelength observations and analysis of a solar coronal jet and coronal mass ejection (CME) event. Employing the GCS model, we obtained the real (three-dimensional) heliocentric distance and direction of the CME and found it to propagate at a high speed of over 1000 km s{sup −1}. The jet erupted before the CME and shared the same source region. The temporal and spacial relationship between these two events lead us to the possibility that the jet triggered the CME and became its core. This scenario hold the promise of enriching our understanding of the triggering mechanism of CMEs and their relations to coronal large-scale jets. On the other hand, the magnetic field configuration of the source region observed by the Solar Dynamics Observatory (SDO)/HMI instrument along with the off-limb inverse Y-shaped configuration observed by SDO/AIA in the 171 Å passband provide the first detailed observation of the three-dimensional reconnection process of a large-scale jet as simulated in Pariat et al. The eruption process of the jet highlights the importance of filament-like material during the eruption of not only small-scale X-ray jets, but likely also of large-scale EUV jets. Based on our observations and analysis, we propose the most probable mechanism for the whole event, with a blob structure overlaying the three-dimensional structure of the jet, to describe the interaction between the jet and the CME.

  1. Evidence for mass outflow in the low solar corona over a large sunspot

    NASA Technical Reports Server (NTRS)

    Neupert, Werner M.; Brosius, Jeffrey W.; Thomas, Roger J.; Thompson, William T.

    1992-01-01

    Spatially resolved EUV coronal emission-line profiles have been obtained in a solar active region, including a large sunspot, using an EUV imaging spectrograph. Relative Doppler velocities were measured in the lines of Mg IX, Fe XV, and Fe XVI with a sensitivity of 2-3 km/s at 350 A. The only significant Doppler shift occurred over the umbra of the large sunspot, in the emission line of Mg IX (at Te of about 1.1 x 10 exp 6 K). The maximum shift corresponded to a peak velocity toward the observer of 14 +/- 3 km/s relative to the mean of measurements in this emission line made elsewhere over the active region. The magnetic field in the low corona was aligned to within 10 deg of the line of sight at the location of maximum Doppler shift. Depending on the closure of the field, such a mass flow could either contribute to the solar wind or reappear as a downflow of material in distant regions on the solar surface. The site of the source, near a major photospheric field boundary, was consistent with origins of low-speed solar wind typically inferred from interplanetary plasma observations.

  2. Nominal Values for Selected Solar and Planetary Quantities: IAU 2015 Resolution B3

    NASA Astrophysics Data System (ADS)

    Prša, Andrej; Harmanec, Petr; Torres, Guillermo; Mamajek, Eric; Asplund, Martin; Capitaine, Nicole; Christensen-Dalsgaard, Jørgen; Depagne, Éric; Haberreiter, Margit; Hekker, Saskia; Hilton, James; Kopp, Greg; Kostov, Veselin; Kurtz, Donald W.; Laskar, Jacques; Mason, Brian D.; Milone, Eugene F.; Montgomery, Michele; Richards, Mercedes; Schmutz, Werner; Schou, Jesper; Stewart, Susan G.

    2016-08-01

    In this brief communication we provide the rationale for and the outcome of the International Astronomical Union (IAU) resolution vote at the XXIXth General Assembly in Honolulu, Hawaii, in 2015, on recommended nominal conversion constants for selected solar and planetary properties. The problem addressed by the resolution is a lack of established conversion constants between solar and planetary values and SI units: a missing standard has caused a proliferation of solar values (e.g., solar radius, solar irradiance, solar luminosity, solar effective temperature, and solar mass parameter) in the literature, with cited solar values typically based on best estimates at the time of paper writing. As precision of observations increases, a set of consistent values becomes increasingly important. To address this, an IAU Working Group on Nominal Units for Stellar and Planetary Astronomy formed in 2011, uniting experts from the solar, stellar, planetary, exoplanetary, and fundamental astronomy, as well as from general standards fields to converge on optimal values for nominal conversion constants. The effort resulted in the IAU 2015 Resolution B3, passed at the IAU General Assembly by a large majority. The resolution recommends the use of nominal solar and planetary values, which are by definition exact and are expressed in SI units. These nominal values should be understood as conversion factors only, not as the true solar/planetary properties or current best estimates. Authors and journal editors are urged to join in using the standard values set forth by this resolution in future work and publications to help minimize further confusion.

  3. Two-step forecast of geomagnetic storm using coronal mass ejection and solar wind condition.

    PubMed

    Kim, R-S; Moon, Y-J; Gopalswamy, N; Park, Y-D; Kim, Y-H

    2014-04-01

    To forecast geomagnetic storms, we had examined initially observed parameters of coronal mass ejections (CMEs) and introduced an empirical storm forecast model in a previous study. Now we suggest a two-step forecast considering not only CME parameters observed in the solar vicinity but also solar wind conditions near Earth to improve the forecast capability. We consider the empirical solar wind criteria derived in this study (Bz  ≤ -5 nT or Ey  ≥ 3 mV/m for t≥ 2 h for moderate storms with minimum Dst less than -50 nT) and a Dst model developed by Temerin and Li (2002, 2006) (TL model). Using 55 CME-Dst pairs during 1997 to 2003, our solar wind criteria produce slightly better forecasts for 31 storm events (90%) than the forecasts based on the TL model (87%). However, the latter produces better forecasts for 24 nonstorm events (88%), while the former correctly forecasts only 71% of them. We then performed the two-step forecast. The results are as follows: (i) for 15 events that are incorrectly forecasted using CME parameters, 12 cases (80%) can be properly predicted based on solar wind conditions; (ii) if we forecast a storm when both CME and solar wind conditions are satisfied (∩), the critical success index becomes higher than that from the forecast using CME parameters alone, however, only 25 storm events (81%) are correctly forecasted; and (iii) if we forecast a storm when either set of these conditions is satisfied (∪), all geomagnetic storms are correctly forecasted.

  4. Two-step forecast of geomagnetic storm using coronal mass ejection and solar wind condition

    PubMed Central

    Kim, R-S; Moon, Y-J; Gopalswamy, N; Park, Y-D; Kim, Y-H

    2014-01-01

    To forecast geomagnetic storms, we had examined initially observed parameters of coronal mass ejections (CMEs) and introduced an empirical storm forecast model in a previous study. Now we suggest a two-step forecast considering not only CME parameters observed in the solar vicinity but also solar wind conditions near Earth to improve the forecast capability. We consider the empirical solar wind criteria derived in this study (Bz ≤ −5 nT or Ey ≥ 3 mV/m for t≥ 2 h for moderate storms with minimum Dst less than −50 nT) and a Dst model developed by Temerin and Li (2002, 2006) (TL model). Using 55 CME-Dst pairs during 1997 to 2003, our solar wind criteria produce slightly better forecasts for 31 storm events (90%) than the forecasts based on the TL model (87%). However, the latter produces better forecasts for 24 nonstorm events (88%), while the former correctly forecasts only 71% of them. We then performed the two-step forecast. The results are as follows: (i) for 15 events that are incorrectly forecasted using CME parameters, 12 cases (80%) can be properly predicted based on solar wind conditions; (ii) if we forecast a storm when both CME and solar wind conditions are satisfied (∩), the critical success index becomes higher than that from the forecast using CME parameters alone, however, only 25 storm events (81%) are correctly forecasted; and (iii) if we forecast a storm when either set of these conditions is satisfied (∪), all geomagnetic storms are correctly forecasted. PMID:26213515

  5. MAXIMUM CORONAL MASS EJECTION SPEED AS AN INDICATOR OF SOLAR AND GEOMAGNETIC ACTIVITIES

    SciTech Connect

    Kilcik, A.; Yurchyshyn, V. B.; Abramenko, V.; Goode, P. R.; Gopalswamy, N.; Ozguc, A.; Rozelot, J. P.

    2011-01-20

    We investigate the relationship between the monthly averaged maximal speeds of coronal mass ejections (CMEs), international sunspot number (ISSN), and the geomagnetic Dst and Ap indices covering the 1996-2008 time interval (solar cycle 23). Our new findings are as follows. (1) There is a noteworthy relationship between monthly averaged maximum CME speeds and sunspot numbers, Ap and Dst indices. Various peculiarities in the monthly Dst index are correlated better with the fine structures in the CME speed profile than that in the ISSN data. (2) Unlike the sunspot numbers, the CME speed index does not exhibit a double peak maximum. Instead, the CME speed profile peaks during the declining phase of solar cycle 23. Similar to the Ap index, both CME speed and the Dst indices lag behind the sunspot numbers by several months. (3) The CME number shows a double peak similar to that seen in the sunspot numbers. The CME occurrence rate remained very high even near the minimum of the solar cycle 23, when both the sunspot number and the CME average maximum speed were reaching their minimum values. (4) A well-defined peak of the Ap index between 2002 May and 2004 August was co-temporal with the excess of the mid-latitude coronal holes during solar cycle 23. The above findings suggest that the CME speed index may be a useful indicator of both solar and geomagnetic activities. It may have advantages over the sunspot numbers, because it better reflects the intensity of Earth-directed solar eruptions.

  6. The high performance solar array GSR3

    NASA Astrophysics Data System (ADS)

    Mamode, A.; Bartevian, J.; Bastard, J. L.; Auffray, P.; Plagne, A.

    A foldout solar array for communication satellites was developed. A wing composed of 4 panels of 1.6 x 1.5 m and a Y-shaped yoke, and a wing with 3 panels of 2.4 x 2.4 m were made. End of life performance goal is greater than 35 W/kg with BSR 180 micron solar cells, and 50 W/kg using 50 micron BSFR cells. Analysis shows that all identified requirements can be covered with current skin made of open weave very high modulus carbon fiber; reinforcements of unidirectional carbon fiber; honeycomb in current section; hold-down inserts made of wound carbon fibers; titanium hinge fitting; and Kapton foil (25 or 50 micron thickness). Tests confirm performance predictions.

  7. Numerical study of the propagation characteristics of coronal mass ejections in a structured ambient solar wind

    NASA Astrophysics Data System (ADS)

    Zhou, Yufen; Feng, Xueshang

    2017-02-01

    Using a three-dimensional (3-D) magnetohydrodynamics (MHD) model, we analyze and study the propagation characteristics of coronal mass ejections (CMEs) launched at different positions in a realistic structured ambient solar wind. Here the ambient solar wind structure during the Carrington rotation 2095 is selected, which is the characteristics of activity rising phase. CMEs with a simple spherical plasmoid structure are initiated at different solar latitudes with respect to the heliospheric current sheet (HCS) and the Earth in the same ambient solar wind. Then, we numerically obtained the evolution process of the CMEs from the Sun to the interplanetary space. When the Earth and the CME launch position are located on the same side of the HCS, the arrival time of the shock at the Earth is faster than that when the Earth and the CME launch position are located on the opposite side of the HCS. The disturbance amplitudes for the same side event are also larger than those for the opposite side event. This may be due to the fact that the HCS between the CME and the Earth for the opposite side event hinders its propagation and weaken it. The CMEs tend to deflect toward the HCS in the latitudinal direction near the corona and then propagate almost parallel to the HCS in the interplanetary space. This deflecting tendency may be caused by the dynamic action of near-Sun magnetic pressure gradient force on the ejected coronal plasma.

  8. Scaling Relations in Coronal Mass Ejections and Energetic Proton Events Associated with Solar Superflares

    NASA Astrophysics Data System (ADS)

    Takahashi, Takuya; Mizuno, Yoshiyuki; Shibata, Kazunari

    2016-12-01

    In order to discuss the potential impact of solar “superflares” on space weather, we investigated statistical relations among energetic proton peak flux with energy higher than 10 MeV (F p ), CME speed near the Sun (V CME) obtained by Solar and Heliospheric Observatory/LASCO coronagraph, and flare soft X-ray peak flux in the 1-8 Å band (F SXR) during 110 major solar proton events recorded from 1996 to 2014. The linear regression fit results in the scaling relations {V}{CME}\\propto {F}{SXR}α , {F}p\\propto {F}{SXR}β , and {F}p\\propto {V}{CME}γ with α = 0.30 ± 0.04, β = 1.19 ± 0.08, and γ = 4.35 ± 0.50, respectively. On the basis of simple physical assumptions, on the other hand, we derive scaling relations expressing CME mass (M CME), CME speed, and energetic proton flux in terms of total flare energy (E flare) as {M}{CME}\\propto {E}{flare}2/3, {V}{CME}\\propto {E}{flare}1/6, and {F}p\\propto {E}{flare}5/6\\propto {V}{CME}5, respectively. We then combine the derived scaling relations with observation and estimated the upper limit of V CME and F p to be associated with possible solar superflares.

  9. Coronal mass ejections and the injection profiles of solar energetic particle events

    NASA Technical Reports Server (NTRS)

    Kahler, S. W.; Reames, D. V.; Sheeley, N. R., Jr.

    1990-01-01

    Previous studies using Skylab and Solwind coronagraph observations have shown that almost all E greater than 10 MeV solar energetic proton (SEP) events are associated with the occurrence of a coronal mass ejection (CME). These earlier studies did not address the relationship between the position of the associated CME and the timing of the injection of particles into the interplanetary medium. Ten cases are selected in which a SEP event observed with the GSFC detectors on the IMP 8 or ISEE 3 spacecraft was correlated to a CME well observed by the Solwind coronagraph. The height of the leading edge of the CME is compared with the particle injection profiles for several energy ranges using the solar release times for the particles. The derived injection profiles are found to be increasing and sometimes reaching maximum while the associated CMEs are at heights of 2-10 Ro.

  10. The 3D structure of Coronal Mass Ejections

    NASA Astrophysics Data System (ADS)

    Patsourakos, Spiros

    2016-07-01

    Coronal Mass Ejections (CMEs) represent one of the most powerful energy release phenomena in the entire solar system and are a major driver of space weather. Prior to 2006, our observational access to CMEs was limited to single viewpoint remote sensing observations in the inner/outer corona, and in-situ observations further away, e.g. at 1 AU. Taking all these factors together, turned out to be a major obstacle in our understanding and characterizing of the 3D structure and evolution of CMEs. The situation improved dramatically with the availability of multi-viewpoint imaging observations of CMEs, all way through from the Sun to 1 AU, from the STEREO mission since 2006, combined with observations from other missions (SOHO, Hinode, SDO, IRIS). With this talk we will discuss several key recent results in CME science resulting from the analysis of multi-viewpoint observations. This includes: (1) shape and structure; (2) kinematics and energetics; (3) trajectories, deflections and rotations; (4) arrival times and velocities at 1 AU; (5) magnetic field structure; (6) relationships with coronal and interplanetary shocks and solar energetic particles. The implications of these results in terms of CME theories and models will be also addressed. We will conclude with a discussion of important open issues in our understanding of CMEs and how these could be addressed with upcoming (Solar Orbiter, Solar Probe Plus) and under-study missions (e.g., L5).

  11. Radio Tracking of a White-Light Coronal Mass Ejection from Solar Corona to Interplanetary Medium.

    PubMed

    Reiner; Kaiser; Plunkett; Prestage; Manning

    2000-01-20

    For a solar flare/coronal mass ejection (CME) event on 1999 May 3, type II radio emissions were observed from the metric through the hectometric wavelength regimes. By comparing the dynamics of the CME with that implied by the frequency range and frequency drift rates of the type II radio emissions, it is concluded that the decametric-hectometric type II radio emissions were associated with the CME. The dynamics implied by the metric type II radio burst suggest a distinct coronal shock, associated with the flare, which only produced radio emissions in the low corona.

  12. Neutrino mass model with S3 symmetry and seesaw interplay

    NASA Astrophysics Data System (ADS)

    Pramanick, Soumita; Raychaudhuri, Amitava

    2016-12-01

    We develop a seesaw model for neutrino masses and mixing with an S3×Z3 symmetry. It involves an interplay of type-I and type-II seesaw contributions of which the former is subdominant. The S3×Z3 quantum numbers of the fermion and scalar fields are chosen such that the type-II seesaw generates a mass matrix which incorporates the atmospheric mass splitting and sets θ23=π /4 . The solar splitting and θ13 are absent, while the third mixing angle can achieve any value, θ120. Specific choices of θ120 are of interest, e.g., 35.3° (tribimaximal), 45.0° (bimaximal), 31.7° (golden ratio), and 0° (no solar mixing). The role of the type-I seesaw is to nudge all the above into the range indicated by the data. The model results in novel interrelationships between these quantities due to their common origin, making it readily falsifiable. For example, normal (inverted) ordering is associated with θ23 in the first (second) octant. C P violation is controlled by phases in the right-handed neutrino Majorana mass matrix, Mν R . In their absence, only normal ordering is admissible. When Mν R is complex, the Dirac C P phase, δ , can be large, i.e., ˜±π /2 , and inverted ordering is also allowed. The preliminary results from T2K and NOVA which favor normal ordering and δ ˜-π /2 are indicative, in this model, of a lightest neutrino mass of 0.05 eV or more.

  13. The solar thermal report. Volume 3, Number 5

    SciTech Connect

    1982-09-01

    This report is published by the Jet Propulsion Laboratory for the DOE Solar Thermal Technology Division to provide an account of work sponsored by the Division and to aid the community of people interested in solar thermal technology in gaining access to technical information. Contents include articles entitled the following: Solar system supplies thermal energy for producing chemicals at USS plant; Solar thermal power module designed for small community market; Roof-mounted trough system supplies process heat for Caterpillar plant; Solar thermal update -- 10 MW(e) pilot plant and 3-MW(t) total energy system; Solar steam processes crude oil; New York investigates solar ponds as a source of thermal energy; On-farm solar -- Finding new uses for the sun; and Topical index of solar thermal report articles.

  14. The Solar Atmosphere at Three Temperatures During a Coronal Mass Ejection

    NASA Technical Reports Server (NTRS)

    Zhitnik, I.; Pertzov, A.; Oparin, S.; Oraevsky, V.; Slemzin, V.; Sobelman, I.; Feynman, J.; Goldstein, B.

    1998-01-01

    On April 14, 1994 a major coronal mass ejection (CME) occured while the solar atmosphere was being observed in XUV by the Terek C instrument aboard the CORONAS spacecraft. We here compare the TEREK data before and after the CME with the Yohkoh soft x-ray data and the National Solar Observatory He I 10830 data from April 13 and 14.

  15. LITHIUM ABUNDANCE AS A PREDICTOR OF MASS AND AGE IN SOLAR-ANALOG STARS

    SciTech Connect

    Li, T. D.; Bi, S. L.; Liu, K.; Tian, Z. J.; Ge, Z. S.; Chen, Y. Q.

    2012-02-20

    In order to estimate the mass and age of stars, we construct a grid of stellar models for eight solar-analog stars including diffusion and rotation-induced mixing for the given ranges of stellar mass, metallicity, and rotational rate. By combining stellar models with observational data including lithium abundance, we obtain more accurate estimations of mass and age for solar-analog stars. The results indicate that stars HIP 56948, HIP 73815, and HIP 78399 are three possible solar twins. Furthermore, we find that lithium depletion due to extra-mixing in solar analogs strongly depends on mass, metallicity, and rotational history. Therefore, lithium abundance can be used as a good constraint in stellar modeling.

  16. Self-sustained strong mass transfer without Roche lobe overflow - Cygnus X-3

    NASA Technical Reports Server (NTRS)

    Tavani, Marco; Ruderman, Malvin; Shaham, Jacob

    1989-01-01

    It is proposed that the binary evolution of Cyg X-3 is driven by a self-excited wind from a solar composition companion star sustained by radiation from a neutron star primary. Observations would then imply that the companion is a white dwarf underfilling its Roche lobe, with mass between 0.01 and 0.03 solar masses. Cyg X-3 could then be in the late stage of very low mass X-ray binary evolution expected to result in a millisecond pulsar binary similar to the eclipsing system PSR 1957 + 20.

  17. Self-sustained strong mass transfer without Roche lobe overflow - Cygnus X-3

    NASA Astrophysics Data System (ADS)

    Tavani, Marco; Ruderman, Malvin; Shaham, Jacob

    1989-07-01

    It is proposed that the binary evolution of Cyg X-3 is driven by a self-excited wind from a solar composition companion star sustained by radiation from a neutron star primary. Observations would then imply that the companion is a white dwarf underfilling its Roche lobe, with mass between 0.01 and 0.03 solar masses. Cyg X-3 could then be in the late stage of very low mass X-ray binary evolution expected to result in a millisecond pulsar binary similar to the eclipsing system PSR 1957 + 20.

  18. Passive solar design handbook. Volume 3: Passive solar design analysis

    NASA Astrophysics Data System (ADS)

    Jones, R. W.; Bascomb, J. D.; Kosiewicz, C. E.; Lazarus, G. S.; McFarland, R. D.; Wray, W. O.

    1982-07-01

    Simple analytical methods concerning the design of passive solar heating systems are presented with an emphasis on the average annual heating energy consumption. Key terminology and methods are reviewed. The solar load ratio (SLR) is defined, and its relationship to analysis methods is reviewed. The annual calculation, or Load Collector Ratio (LCR) method, is outlined. Sensitivity data are discussed. Information is presented on balancing conservation and passive solar strategies in building design. Detailed analysis data are presented for direct gain and sunspace systems, and details of the systems are described. Key design parameters are discussed in terms of their impact on annual heating performance of the building. These are the sensitivity data. The SLR correlations for the respective system types are described. The monthly calculation, or SLR method, based on the SLR correlations, is reviewed. Performance data are given for 9 direct gain systems and 15 water wall and 42 Trombe wall systems.

  19. DENSITY DIAGNOSTICS OF CORONAL MASS EJECTION CORES WITH THE SOLAR DYNAMICS OBSERVATORY/ATMOSPHERIC IMAGING ASSEMBLY

    SciTech Connect

    Landi, E.; Miralles, M. P.

    2014-01-01

    In this Letter, we investigate the application of the intensity ratio from pairs of narrow-band images from the Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory, the Extreme Ultraviolet (EUV) Imager (EUVI) on board the Sun Earth Connection Coronal and Heliospheric Investigation, and the EUV Imaging Telescope (EIT) on board the Solar and Heliospheric Observatory, to density diagnostics of optically thin plasmas. By inspecting the filtered spectra allowed by each instrument's effective area, we find that ratios between AIA images in the 171 Å and 193 Å channels can be used to determine the plasma electron density at transition region temperatures. This diagnostic potential is due to a pair of O V transitions which dominate the effective spectra of these two channels at temperatures around ≈2.5-3.0 × 10{sup 5} K. The temperature and electron density ranges where the 171/193 ratio is density sensitive are relevant for the cores of accelerating coronal mass ejections (CMEs) in the inner solar corona. We discuss how AIA series of images can be used for simultaneous temperature and density diagnostics of CME cores.

  20. Realization of improved efficiency on nanostructured multicrystalline silicon solar cells for mass production.

    PubMed

    Lin, X X; Zeng, Y; Zhong, S H; Huang, Z G; Qian, H Q; Ling, J; Zhu, J B; Shen, W Z

    2015-03-27

    We report the realization of both excellent optical and electrical properties of nanostructured multicrystalline silicon solar cells by a simple and industrially compatible technique of surface morphology modification. The nanostructures are prepared by Ag-catalyzed chemical etching and subsequent NaOH treatment with controllable geometrical parameters and surface area enhancement ratio. We have examined in detail the influence of different surface area enhancement ratios on reflectance, carrier recombination characteristics and cell performance. By conducting a quantitative analysis of these factors, we have successfully demonstrated a higher-than-traditional output performance of nanostructured multicrystalline silicon solar cells with a low average reflectance of 4.93%, a low effective surface recombination velocity of 6.59 m s(-1), and a certified conversion efficiency of 17.75% on large size (156 × 156 mm(2)) silicon cells, which is ∼0.3% higher than the acid textured counterparts. The present work opens a potential prospect for the mass production of nanostructured solar cells with improved efficiencies.

  1. Two-Step Forecast of Geomagnetic Storm Using Coronal Mass Ejection and Solar Wind Condition

    NASA Technical Reports Server (NTRS)

    Kim, R.-S.; Moon, Y.-J.; Gopalswamy, N.; Park, Y.-D.; Kim, Y.-H.

    2014-01-01

    To forecast geomagnetic storms, we had examined initially observed parameters of coronal mass ejections (CMEs) and introduced an empirical storm forecast model in a previous study. Now we suggest a two-step forecast considering not only CME parameters observed in the solar vicinity but also solar wind conditions near Earth to improve the forecast capability. We consider the empirical solar wind criteria derived in this study (Bz = -5 nT or Ey = 3 mV/m for t = 2 h for moderate storms with minimum Dst less than -50 nT) (i.e. Magnetic Field Magnitude, B (sub z) less than or equal to -5 nanoTeslas or duskward Electrical Field, E (sub y) greater than or equal to 3 millivolts per meter for time greater than or equal to 2 hours for moderate storms with Minimum Disturbance Storm Time, Dst less than -50 nanoTeslas) and a Dst model developed by Temerin and Li (2002, 2006) (TL [i.e. Temerin Li] model). Using 55 CME-Dst pairs during 1997 to 2003, our solar wind criteria produce slightly better forecasts for 31 storm events (90 percent) than the forecasts based on the TL model (87 percent). However, the latter produces better forecasts for 24 nonstorm events (88 percent), while the former correctly forecasts only 71 percent of them. We then performed the two-step forecast. The results are as follows: (i) for 15 events that are incorrectly forecasted using CME parameters, 12 cases (80 percent) can be properly predicted based on solar wind conditions; (ii) if we forecast a storm when both CME and solar wind conditions are satisfied (n, i.e. cap operator - the intersection set that is comprised of all the elements that are common to both), the critical success index becomes higher than that from the forecast using CME parameters alone, however, only 25 storm events (81 percent) are correctly forecasted; and (iii) if we forecast a storm when either set of these conditions is satisfied (?, i.e. cup operator - the union set that is comprised of all the elements of either or both

  2. Probing the eV-Mass Range for Solar Axions with CAST

    SciTech Connect

    Vogel, J K; Pivovaroff, M J; Soufli, R; van Bibber, K; CAST, C

    2010-11-11

    The CERN Axion Solar Telescope (CAST) is searching for solar axions which could be produced in the core of the Sun via the so-called Primakoff effect. Not only would these hypothetical particles solve the strong CP problem, but they are also one of the favored candidates for dark matter. In order to look for axions originating from the Sun, CAST uses a decommissioned LHC prototype magnet. In its 10 m long magnetic field region of 9 Tesla, axions could be reconverted into X-ray photons. Different X-ray detectors are installed on both ends of the magnet, which is mounted on a structure built to follow the Sun during sunrise and sunset for a total of about 3 hours per day. The analysis of the data acquired during the first phase of the experiment with vacuum in the magnetic field region yielded the most restrictive experimental upper limit on the axion-to-photon coupling constant for axion masses up to about 0.02 eV. In order to extend the sensitivity of the experiment to a wider mass range, the CAST experiment continues its search for axions with helium in the magnet bores. In this way it is possible to restore coherence of conversion for larger masses. Changing the pressure of the helium gas enables the experiment to scan different axion masses in the range of up to about 1.2 eV. Especially at high pressures, a precise knowledge of the gas density distribution is crucial to obtain accurate results. In the first part of this second phase of CAST, {sup 4}He was used and the axion mass region was extended up to 0.39 eV, a part of phase space favored by axion models. In CAST's ongoing {sup 3}He phase the studied mass range is now being extended further. In this contribution the final results of CAST's {sup 4}He phase will be presented and the current status of the {sup 3}He run will be given. This includes latest results as well as prospects of future axion experiments.

  3. Mass-loading of the solar wind at 67P/Churyumov-Gerasimenko. Observations and modelling

    NASA Astrophysics Data System (ADS)

    Behar, E.; Lindkvist, J.; Nilsson, H.; Holmström, M.; Stenberg-Wieser, G.; Ramstad, R.; Götz, C.

    2016-11-01

    Context. The first long-term in-situ observation of the plasma environment in the vicinity of a comet, as provided by the European Rosetta spacecraft. Aims: Here we offer characterisation of the solar wind flow near 67P/Churyumov-Gerasimenko (67P) and its long term evolution during low nucleus activity. We also aim to quantify and interpret the deflection and deceleration of the flow expected from ionization of neutral cometary particles within the undisturbed solar wind. Methods: We have analysed in situ ion and magnetic field data and combined this with hybrid modeling of the interaction between the solar wind and the comet atmosphere. Results: The solar wind deflection is increasing with decreasing heliocentric distances, and exhibits very little deceleration. This is seen both in observations and in modeled solar wind protons. According to our model, energy and momentum are transferred from the solar wind to the coma in a single region, centered on the nucleus, with a size in the order of 1000 km. This interaction affects, over larger scales, the downstream modeled solar wind flow. The energy gained by the cometary ions is a small fraction of the energy available in the solar wind. Conclusions: The deflection of the solar wind is the strongest and clearest signature of the mass-loading for a small, low-activity comet, whereas there is little deceleration of the solar wind.

  4. Advanced solar concentrator mass production, operation, and maintenance cost assessment

    NASA Technical Reports Server (NTRS)

    Niemeyer, W. A.; Bedard, R. J.; Bell, D. M.

    1981-01-01

    The object of this assessment was to estimate the costs of the preliminary design at: production rates of 100 to 1,000,000 concentrators per year; concentrators per aperture diameters of 5, 10, 11, and 15 meters; and various receiver/power conversion package weights. The design of the cellular glass substrate Advanced Solar Concentrator is presented. The concentrator is an 11 meter diameter, two axis tracking, parabolic dish solar concentrator. The reflective surface of this design consists of inner and outer groups of mirror glass/cellular glass gores.

  5. Solar Wind Mass-Loading Due to Dust in the Vicinity of the Sun

    NASA Astrophysics Data System (ADS)

    Rasca, A.; Horanyi, M.

    2012-12-01

    Collisionless shocks due to mass-loading were first discussed to describe the solar wind flow around a cometary atmosphere, showing its choking effects on the flow. Recent observations have led to an increased interest in mass-loading occurring in the solar corona, due to sun-grazing comets and also due to collisional debris production by sunward migrating interplanetary dust particles. Using one-dimensional simulations with a hydrodynamic model we have shown the impact on the solar wind from abrupt mass-loading in the coronal region. Full three-dimensional MHD simulations using the Block-Adaptive-Tree-Solarwind-Roe-Upwind-Scheme (BATS-R-US) accomplish more to mimic specific events applicable to modeling the mass-loaded coronal wind caused by the presence of a sun-grazing comet, for example.

  6. Interactions of Dust Grains with Coronal Mass Ejections and Solar Cycle Variations of the F-Coronal Brightness

    NASA Technical Reports Server (NTRS)

    Ragot, B. R.; Kahler, S. W.

    2003-01-01

    The density of interplanetary dust increases sunward to reach its maximum in the F corona, where its scattered white-light emission dominates that of the electron K corona above about 3 Solar Radius. The dust will interact with both the particles and fields of antisunward propagating coronal mass ejections (CMEs). To understand the effects of the CME/dust interactions we consider the dominant forces, with and without CMEs. acting on the dust in the 3-5 Solar Radius region. Dust grain orbits are then computed to compare the drift rates from 5 to 3 Solar Radius. for periods of minimum and maximum solar activity, where a simple CME model is adopted to distinguish between the two periods. The ion-drag force, even in the quiet solar wind, reduces the drift time by a significant factor from its value estimated with the Poynting-Robertson drag force alone. The ion-drag effects of CMEs result in even shorter drift times of the large (greater than or approx. 3 microns) dust grains. hence faster depletion rates and lower dust-pain densities, at solar maxima. If dominated by thermal emission, the near-infrared brightness will thus display solar cycle variations close to the dust plane of symmetry. While trapping the smallest of the grains, the CME magnetic fields also scatter the grains of intermediate size (0.1-3 microns) in latitude. If light scattering by small grains close to the Sun dominates the optical brightness. the scattering by the CME magnetic fields will result in a solar cycle variation of the optical brightness distribution not exceeding 100% at high latitudes, with a higher isotropy reached at solar maxima. A good degree of latitudinal isotropy is already reached at low solar activity since the magnetic fields of the quiet solar wind so close to the Sun are able to scatter the small (less than or approx. 3 microns) grains up to the polar regions in only a few days or less, producing strong perturbations of their trajectories in less than half their orbital

  7. The Effects of Post-Main-Sequence Solar Mass Loss on the Stability of Our Planetary System

    NASA Astrophysics Data System (ADS)

    Duncan, Martin J.; Lissauer, Jack J.

    1998-08-01

    We present the results of extensive long-term integrations of systems of planets with orbits initially identical to subsets of the planets within our Solar System, but with the Sun's mass decreased relative to the masses of the planets. For systems based on the giant planets, we find an approximate power-law correlation between the time elapsed until a pair of planetary orbits cross and the solar-to-planetary-mass ratio, provided that this ratio is ≲0.4 times its current value. However, deviations from this relationship at larger ratios suggest that this correlation may not be useful in predicting the lifetime of the current system. Detailed simulations of the evolution of planetary orbits through the solar mass loss phase at the end of the Sun's main-sequence lifetime suggest that the orbits of those terrestrial planets that survive the Sun's red giant phase are likely to remain stable for (possibly much) longer than a billion years and those of the giant planets are likely to remain stable for (possibly much) more than ten billion years. Pluto is likely to escape from its current 2:3 mean-motion resonance with Neptune within a few billion years beyond the Sun's main sequence lifetime if subject only to gravitational forces; its prognosis is likely to be even poorer when nongravitational forces are included. Implications for the effects of stellar mass loss on the stability of other planetary systems are discussed.

  8. First 3D view of solar eruptions

    NASA Astrophysics Data System (ADS)

    2004-07-01

    CME as seen by LASCO Figure 1. A classical three-part CME inside the LASCO C3 field of view, showing a bright frontal loop (shaped like a lightbulb)surrounding a dark cavity with a bright core. This CME is headed roughly 90 degrees away from Earth. The uniform disk in the centre of the image is where the occulter is placed, blocking out all direct sunlight. The approximate size of the Sun is indicated by the white circle in the middle. Click here CME as seen by LASCO Figure 2. A similar CME heading almost directly towards Earth, observed by LASCO C2 which has a smaller field of view than C3. The size of the Sun is indicated by the larger circle, and the x-marked circle on the Sun shows the origin of the CME. Panel a shows the total intensity (darker means more intensity) as imaged directly by LASCO. Only the narrow lower end of the 'lightbulb' shape is visible - the widest portion has expanded beyond the field of view, whereas the front part and the core are too dim to be seen or hidden behind the occulter. Panel d is a topographic map of the material shown in panel a. The distance from the plane of the Sun to the material is colour coded - the scale in units of solar radii is shown on the side. Panels b and c show the intensity as it would have appeared to an observer positioned to the side of the Sun or directly above it, respectively. Click here CMEs are the most powerful eruptions in the Solar System, with thousands of millions of tonnes of electrified gas being blasted from the Sun's atmosphere into space at millions of kilometres per hour. Researchers believe that CMEs are launched when solar magnetic fields become strained and suddenly 'snap' to a new configuration, like a rubber band that has been twisted to the breaking point. To fully understand the origin of these powerful blasts and the process that launches them from the Sun, scientists need to see the structure of CMEs in three dimensions. "Views in three dimensions will help us to better predict CME

  9. Neutrino Mass Seesaw Version 3: Recent Developments

    SciTech Connect

    Ma, Ernest

    2009-04-20

    The origin of neutrino mass is usually attributed to a seesaw mechanism, either through a heavy Majorana fermion singlet (version 1) or a heavy scalar triplet (version 2). Recently, the idea of using a heavy Majorana fermion triplet (version 3) has gained some attention. This is a review of the basic idea involved, its U(1) gauge extension, and some recent developments.

  10. Precise /sup 3/H-/sup 3/He mass difference for neutrino mass determination

    SciTech Connect

    Lippmaa, E.; Pikver, R.; Suurmaa, E.; Past, J.; Puskar, J.; Koppel, I.; Tammik, A.

    1985-01-28

    The precise /sup 3/H-/sup 3/He atomic mass difference has been measured by high-resolution (10/sup -8/) ion cyclotron resonance in a 4.7-T magnetic field. The result of 18 599 +- 2 eV favors a nonzero electron antineutrino mass.

  11. Explaining solar neutrinos with heavy Higgs masses in partial split supersymmetry

    SciTech Connect

    Diaz, Marco Aurelio; Garay, Francisca; Koch, Benjamin

    2009-12-01

    Partial Split Supersymmetry with violation of R-parity as a model for neutrino masses is explored. It is shown that at the one-loop level the model can give predictions that are in agreement with all present experimental values for the neutrino sector. An analytical result is that the small solar neutrino mass difference can be naturally explained in the decoupling limit for the heavy Higgs mass eigenstates.

  12. Activity associated with coronal mass ejections at solar minimum - SMM observations from 1984-1986

    NASA Technical Reports Server (NTRS)

    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.

  13. A low-mass faraday cup experiment for the solar wind

    NASA Technical Reports Server (NTRS)

    Lazarus, A. J.; Steinberg, J. T.; Mcnutt, R. L., Jr.

    1993-01-01

    Faraday cups have proven to be very reliable and accurate instruments capable of making 3-D velocity distribution measurements on spinning or 3-axis stabilized spacecraft. Faraday cup instrumentation continues to be appropriate for heliospheric missions. As an example, the reductions in mass possible relative to the solar wind detection system about to be flown on the WIND spacecraft were estimated. Through the use of technology developed or used at the MIT Center for Space Research but were not able to utilize for WIND: surface-mount packaging, field-programmable gate arrays, an optically-switched high voltage supply, and an integrated-circuit power converter, it was estimated that the mass of the Faraday Cup system could be reduced from 5 kg to 1.8 kg. Further redesign of the electronics incorporating hybrid integrated circuits as well as a decrease in the sensor size, with a corresponding increase in measurement cycle time, could lead to a significantly lower mass for other mission applications. Reduction in mass of the entire spacecraft-experiment system is critically dependent on early and continual collaborative efforts between the spacecraft engineers and the experimenters. Those efforts concern a range of issues from spacecraft structure to data systems to the spacecraft power voltage levels. Requirements for flight qualification affect use of newer, lighter electronics packaging and its implementation; the issue of quality assurance needs to be specifically addressed. Lower cost and reduced mass can best be achieved through the efforts of a relatively small group dedicated to the success of the mission. Such a group needs a fixed budget and greater control over quality assurance requirements, together with a reasonable oversight mechanism.

  14. Predictions for Dusty Mass Loss from Asteroids During Close Encounters with Solar Probe Plus

    NASA Astrophysics Data System (ADS)

    Cranmer, Steven R.

    2016-11-01

    The Solar Probe Plus ( SPP) mission will explore the Sun's corona and innermost solar wind starting in 2018. The spacecraft will also come close to a number of Mercury-crossing asteroids with perihelia less than 0.3 AU. At small heliocentric distances, these objects may begin to lose mass, thus becoming "active asteroids" with comet-like comae or tails. This paper assembles a database of 97 known Mercury-crossing asteroids that may be encountered by SPP, and it presents estimates of their time-dependent visible-light fluxes and mass loss rates. Assuming a similar efficiency of sky background subtraction as was achieved by STEREO , we find that approximately 80 % of these asteroids are bright enough to be observed by the Wide-field Imager for SPP (WISPR). A model of gas/dust mass loss from these asteroids is developed and calibrated against existing observations. This model is used to estimate the visible-light fluxes and spatial extents of spherical comae. Observable dust clouds occur only when the asteroids approach the Sun closer than 0.2 AU. The model predicts that during the primary SPP mission between 2018 and 2025, there should be 113 discrete events (for 24 unique asteroids) during which the modeled comae have angular sizes resolvable by WISPR. The largest of these correspond to asteroids 3200 Phaethon, 137924, 155140, and 289227, all with angular sizes of roughly 15-30 arcminutes. We note that the SPP trajectory may still change, but no matter the details there should still be multiple opportunities for fruitful asteroid observations.

  15. Global Energetics of Solar Flares. V. Energy Closure in Flares and Coronal Mass Ejections

    NASA Astrophysics Data System (ADS)

    Aschwanden, Markus J.; Caspi, Amir; Cohen, Christina M. S.; Holman, Gordon; Jing, Ju; Kretzschmar, Matthieu; Kontar, Eduard P.; McTiernan, James M.; Mewaldt, Richard A.; O’Flannagain, Aidan; Richardson, Ian G.; Ryan, Daniel; Warren, Harry P.; Xu, Yan

    2017-02-01

    In this study we synthesize the results of four previous studies on the global energetics of solar flares and associated coronal mass ejections (CMEs), which include magnetic, thermal, nonthermal, and CME energies in 399 solar M- and X-class flare events observed during the first 3.5 yr of the Solar Dynamics Observatory (SDO) mission. Our findings are as follows. (1) The sum of the mean nonthermal energy of flare-accelerated particles ({E}{nt}), the energy of direct heating ({E}{dir}), and the energy in CMEs ({E}{CME}), which are the primary energy dissipation processes in a flare, is found to have a ratio of ({E}{nt}+{E}{dir}+{E}{CME})/{E}{mag}=0.87+/- 0.18, compared with the dissipated magnetic free energy {E}{mag}, which confirms energy closure within the measurement uncertainties and corroborates the magnetic origin of flares and CMEs. (2) The energy partition of the dissipated magnetic free energy is: 0.51 ± 0.17 in nonthermal energy of ≥slant 6 {keV} electrons, 0.17 ± 0.17 in nonthermal ≥slant 1 {MeV} ions, 0.07 ± 0.14 in CMEs, and 0.07 ± 0.17 in direct heating. (3) The thermal energy is almost always less than the nonthermal energy, which is consistent with the thick-target model. (4) The bolometric luminosity in white-light flares is comparable to the thermal energy in soft X-rays (SXR). (5) Solar energetic particle events carry a fraction ≈ 0.03 of the CME energy, which is consistent with CME-driven shock acceleration. (6) The warm-target model predicts a lower limit of the low-energy cutoff at {e}c≈ 6 {keV}, based on the mean peak temperature of the differential emission measure of T e = 8.6 MK during flares. This work represents the first statistical study that establishes energy closure in solar flare/CME events.

  16. The 3-D solar radioastronomy and the structure of the corona and the solar wind. [solar probes of solar activity

    NASA Technical Reports Server (NTRS)

    Steinberg, J. L.; Caroubalos, C.

    1976-01-01

    The mechanism causing solar radio bursts (1 and 111) is examined. It is proposed that a nonthermal energy source is responsible for the bursts; nonthermal energy is converted into electromagnetic energy. The advantages are examined for an out-of-the-ecliptic solar probe mission, which is proposed as a means of stereoscopically viewing solar radio bursts, solar magnetic fields, coronal structure, and the solar wind.

  17. Solar Flares and Coronal Mass Ejections Are Aspects of Same Event

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    Solar flares and coronal mass ejections from the Sun are intertwined aspects of the same event, rather than two separate events, it was announced at a meeting of the American Astronomical Society's Solar Physics Division on 18 June. The finding resolves ``a chicken-and-egg type of problem as to which came first,'' according to Peter Gallagher, solar physicist with the NASA Goddard Space Flight Center. He said that the problem had been debated for several decades. Gallagher is research scientist for two of the three spacecraft involved with the findings: NASA's Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI), and NASA's Transition Region and Coronal Explorer, (TRACE). The third spacecraft is the Solar and Heliospheric Observatory spacecraft (SOHO), which is a cooperative effort of NASA and the European Space Agency.

  18. Nanoetching process on silicon solar cell wafers during mass production for surface texture improvement.

    PubMed

    Ahn, Chisung; Kulkarni, Atul; Ha, Soohyun; Cho, Yujin; Kim, Jeongin; Park, Heejin; Kim, Taesung

    2014-12-01

    Major challenge in nanotechnology is to improve the solar cells efficiency. This can be achieved by controlling the silicon solar cell wafer surface structure. Herein, we report a KOH wet etching process along with an ultrasonic cleaning process to improve the surface texture of silicon solar cell wafers. We evaluated the KOH temperature, concentration, and ultra-sonication time. It was observed that the surface texture of the silicon solar wafer changed from a pyramid shape to a rectangular shape under edge cutting as the concentration of the KOH solution was increased. We controlled the etching time to avoid pattern damage and any further increase of the reflectance. The present study will be helpful for the mass processing of silicon solar cell wafers with improved reflectance.

  19. Coronal Mass Ejections and Solar Proton Events During the Great March 1989 Disturbances

    NASA Technical Reports Server (NTRS)

    Feynman, J.

    1995-01-01

    The great active region of March 1989 was the most prolific in X- rays in the preceding 15 years, and produced very large bright optical solar flares. The accompanying solar energetic particle event was one of the four most intense episodes since 1963. These increases in particle fluxes are compared to the major X-ray and optical flares and to the major coronal mass ejections in order to test hypothesis.

  20. Western Wind and Solar Integration Study Phase 3: Technical Overview

    SciTech Connect

    2015-11-01

    Technical fact sheet outlining the key findings of Phase 3 of the Western Wind and Solar Integration Study (WWSIS-3). NREL and GE find that with good system planning, sound engineering practices, and commercially available technologies, the Western grid can maintain reliability and stability during the crucial first minute after grid disturbances with high penetrations of wind and solar power.

  1. Solar wind H-3 and C-14 abundances and solar surface processes. [in lunar soil

    NASA Technical Reports Server (NTRS)

    Fireman, E. L.; Defelice, J.; Damico, J.

    1976-01-01

    Tritium is measured as a function of depth in a Surveyor 3 sample. The upper limit for solar-wind-implanted tritium gives an H-3/H-1 limit for the solar wind of 10 to the -11th power. The temperature-release patterns of C-14 from lunar soils are measured. The C-14 release pattern from surface soils differs from a trench-bottom soil and gives positive evidence for the presence of C-14 in the solar wind with a C-14/H-1 ratio of approximately 6 by 10 to the -11th power. This C-14 content fixes a minimal magnitude for nuclear processes on the solar surface averaged over the past 10,000 yr. The H-3 and C-14 contents combine to require that either the mixing rate above the photosphere be rapid or that the H-3 produced by nuclear reactions be destroyed by secondary nuclear reactions before escaping in the solar wind.

  2. Coronal roots of solar wind streams: 3-D MHD modeling

    NASA Technical Reports Server (NTRS)

    Pisanko, Yu. V.

    1995-01-01

    Weak (discontinuous) solutions of the 3-D MHD equations look like a promising tool to model the transonic solar wind with structural elements: current sheets, coronal plumes etc. Using the observational information about various coronal emissions one can include these structural elements into the 3-D MHD solar wind model by embedding the discontinuities of given type. Such 3-D MHD structured solar wind is calculated self-consistently: variants are examined via numerical experiments. In particular, the behavior of coronal plumes in the transonic solar wind flow, is modeled. The input information for numerical modeling (for example, the magnetic field map at the very base of the solar corona) can be adjusted so that fast stream arises over the center of the coronal hole, over the coronal hole boundaries and, even, over the region with closed magnetic topology. 3-D MHD equations have the analytical solution which can serve as a model of supersonic trans-alfvenic solar wind in the (5-20) solar radii heliocentric distance interval. The transverse, nonradial total (gas + magnetic field) pressure balance in the flow is the corner-stone of this solution. The solution describes the filamentation (ray-like structure of the solar corona) and streaming (formation of high-speed streams with velocities up to 800 km/sec) as a consequence of the magnetic field spatial inhomogeneous structure and trans-alfvenic character of the flow. The magnetic field works in the model as a 'controller' for the solar wind streaming and filamentation.

  3. Development of mass-producible line-focus tracking concentrating solar collectors. Category 2: Control systems

    NASA Astrophysics Data System (ADS)

    Hickman, T. E.

    1984-08-01

    The system design criteria and concept of a mass producible modular electronic control system for solar industrial process heating installations are discussed. The control system consists of: the master controller; the weather tower, including a solar tracking angle reference; and overtemperature switch, group control box, tracker/controller, and drive motor for each group of single axis tracking parabolic trough solar collectors. System automatic operation is outlined for unattended installations. The production approach and cost estimates, both based on a production rate of 5 million ft(2) of collector aperature per year, are discussed here. The potential for further development of the system is also presented.

  4. Influence of a stellar wind on the evolution of a star of 30 solar masses

    NASA Technical Reports Server (NTRS)

    Stothers, R.; Chin, C.

    1980-01-01

    A coarse grid of theoretical evolutionary tracks was calculated for a 30 solar mass star to determine the role of mass loss in the evolution of the star during core He burning. The Cox-Stewart opacities were applied, and the rate of mass loss, criterion for convection, and initial chemical composition were taken into consideration. Using the Schwarzschild criterion, the star undergoes little mass loss during core He burning and remains a blue supergiant separated from main sequence stars on the H-R diagram. The stellar remnant consists of the original He core and may appear bluer than equally luminous main sequence stars; a variety of possible evolutionary tracks can be obtained for an initial solar mass of 30 with proper choices of free parameters.

  5. Mass study for modular approaches to a solar electric propulsion module

    NASA Technical Reports Server (NTRS)

    Sharp, G. R.; Cake, J. E.; Oglebay, J. C.; Shaker, F. J.

    1977-01-01

    The propulsion module comprises six to eight 30-cm thruster and power processing units, a mercury propellant storage and distribution system, a solar array ranging in power from 18 to 25 kW, and the thermal and structure systems required to support the thrust and power subsystems. Launch and on-orbit configurations are presented for both modular approaches. The propulsion module satisfies the thermal design requirements of a multimission set including: Mercury, Saturn, and Jupiter orbiters, a 1-AU solar observatory, and comet and asteroid rendezvous. A detailed mass breakdown and a mass equation relating the total mass to the number of thrusters and solar array power requirement is given for both approaches.

  6. Binary Cepheids: Separations and Mass Ratios in 5 Solar Mass Binaries

    DTIC Science & Technology

    2013-10-01

    material: color figures 1. INTRODUCTION Binary-star studies are valuable for what they provide directly (e.g., stellar masses), as well as for the...the high stellar density in the cluster, this could be a chance alignment. 3.2.2. Approximate Orbital Periods We used the angular separations in Table...subsequent evolution of the system will be drastically altered. For Cepheids we have a good estimation of where this effect sets in. Z Lac—not in our sample

  7. The central engine of quasars and AGNs - Scaling to solar mass black holes

    NASA Technical Reports Server (NTRS)

    Kazanas, D.

    1988-01-01

    The model of the previous paper (Ellison and Kazanas, hereafter EK) can be readily scaled to model systems with black holes 3-10 solar masses, such as those expected to exist in certain Galactic X-ray binaries. The model can account in a straightforward way for the bimodal behavior of Cyg X-1 and the other Galactic black hole candidates (White and Marshall 1984; White, et al., 1984). It is argued that the change in the spectrum with luminosity is due to the drastic increase of both the source compactness and luminosity with small changes in the accretion rate, and conversion of most of the energy into electron-positron pairs which render the source optically thick and modify its spectrum. It is also argued that similar effects may be observed in AGNs.

  8. Exploring Mass Loss, Low-Z Accretion, and Convective Overshoot in Solar Models to Mitigate the Solar Abundance Problem

    NASA Astrophysics Data System (ADS)

    Guzik, Joyce Ann; Mussack, Katie

    2010-04-01

    Solar models using the new lower abundances of Asplund et al. or Caffau et al. do not agree as well with helioseismic inferences as models that use the higher Grevesse & Noels or Grevesse & Sauval abundances. Adopting the new abundances leads to models with sound-speed discrepancies of up to 1.4% below the base of the convection zone (CZ) compared to discrepancies of less than 0.4% with the old abundances; a CZ that is too shallow; and a CZ helium abundance that is too low. Here we briefly review recent attempts to restore agreement, and we evaluate three changes to the models: early mass loss, accretion of low-Z material, and convective overshoot. One goal of these attempts is to explore models that could preserve the structure in the interior obtained with the old abundances while accommodating the new abundances at the surface. Although the mass-losing and accretion models show some improvement in agreement with seismic constraints, a satisfactory resolution to the solar abundance problem remains to be found. In addition, we perform a preliminary analysis of models with the Caffau et al. abundances that shows that the sound-speed discrepancy is reduced to only about 0.6% at the CZ base, compared to 1.4% for the Asplund et al. abundances and 0.4% for the Grevesse & Noels abundances. Furthermore, including mass loss in models with the Caffau et al. abundances may improve sound-speed agreement and help resolve the solar lithium problem.

  9. Energy considerations for solar prominences with mass inflow

    NASA Astrophysics Data System (ADS)

    Anzer, U.; Heinzel, P.

    2000-06-01

    In this Letter we study the inflow of enthalpy and ionisation energy into solar prominences. We use 1D stationary slab models for the prominence to calculate this inflow. We compare the resulting energy gain with the integrated radiative losses obtained for such slab models. We find that for reasonable inflow velocities many of our models can be in energy equilibrium; only the very massive prominences will either require some additional heating or they have to cool down to low central temperatures. We also discuss the possibility or heating the prominence by vertical downflows.

  10. Origin of the High-speed Jets Fom Magnetic Flux Emergence in the Solar Transition Region as well as Their Mass and Energy Contribuctions to the Solar Wind

    NASA Astrophysics Data System (ADS)

    Liping, Y.; He, J.; Peter, H.; Tu, C. Y.; Feng, X. S.

    2015-12-01

    In the solar atmosphere, the jets are ubiquitous and found to be at various spatia-temporal scales. They are significant to understand energy and mass transport in the solar atmosphere. Recently, the high-speed transition region jets are reported from the observation. Here we conduct a numerical simulation to investigate the mechanism in their formation, as well as their mass and energy contributions to the solar wind. Driven by the supergranular convection motion, the magnetic reconnection between the magnetic loop and the background open flux occurring in the transition region is simulated with a two-dimensional MHD model. The simulation results show that not only a fast hot jet, much resemble the found transition region jets, but also a adjacent slow cool jet, mostly like classical spicules, is launched. The force analysis shows that the fast hot jet is continually driven by the Lorentz force around the reconnection region, while the slow cool jet is induced by an initial kick through the Lorentz force associated with the emerging magnetic flux. Also, the features of the driven jets change with the amount of the emerging magnetic flux, giving the varieties of both jets.With the developed one-dimensional hydrodynamic solar wind model, the time-dependent pulses are imposed at the bottom to simulate the jet behaviors. The simulation results show that without other energy source, the injected plasmas are accelerated effectively to be a transonic wind with a substantial mass flux. The rapid acceleration occurs close to the Sun, and the resulting asymptotic speeds, number density at 0.3 AU, as well as mass flux normalized to 1 AU are compatible with in site observations. As a result of the high speed, the imposed pulses lead to a train of shocks traveling upward. By tracing the motions of the injected plasma, it is found that these shocks heat and accelerate the injected plasma to make part of them propagate upward and eventually escape. The parametric study shows

  11. OBSERVATION OF HEATING BY FLARE-ACCELERATED ELECTRONS IN A SOLAR CORONAL MASS EJECTION

    SciTech Connect

    Glesener, Lindsay; Bain, Hazel M.; Krucker, Säm; Lin, Robert P.

    2013-12-20

    We report a Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) observation of flare-accelerated electrons in the core of a coronal mass ejection (CME) and examine their role in heating the CME. Previous CME observations have revealed remarkably high thermal energies that can far surpass the CME's kinetic energy. A joint observation by RHESSI and the Atmospheric Imaging Assembly of a partly occulted flare on 2010 November 3 allows us to test the hypothesis that this excess energy is collisionally deposited by flare-accelerated electrons. Extreme ultraviolet (EUV) images show an ejection forming the CME core and sheath, with isothermal multifilter analysis revealing temperatures of ∼11 MK in the core. RHESSI images reveal a large (∼100 × 50 arcsec{sup 2}) hard X-ray (HXR) source matching the location, shape, and evolution of the EUV plasma, indicating that the emerging CME is filled with flare-accelerated electrons. The time derivative of the EUV emission matches the HXR light curve (similar to the Neupert effect observed in soft and HXR time profiles), directly linking the CME temperature increase with the nonthermal electron energy loss, while HXR spectroscopy demonstrates that the nonthermal electrons contain enough energy to heat the CME. This is the most direct observation to date of flare-accelerated electrons heating a CME, emphasizing the close relationship of the two in solar eruptive events.

  12. The Slow and Fast Solar Wind Boundary, Corotating Interaction Regions, and Coronal Mass Ejection observations with Solar Probe Plus and Solar Orbiter (Invited)

    NASA Astrophysics Data System (ADS)

    Velli, M. M.

    2013-12-01

    The Solar Probe Plus and Solar Orbiter missions have as part of their goals to understand the source regions of the solar wind and of the heliospheric magnetic field. In the heliosphere, the solar wind is made up of interacting fast and slow solar wind streams as well as a clearly intermittent source of flow and field, arising from coronal mass ejections (CMEs). In this presentation a summary of the questions associated with the distibution of wind speeds and magnetic fields in the inner heliosphere and their origin on the sun will be summarized. Where and how does the sharp gradient in speeds develop close to the Sun? Is the wind source for fast and slow the same, and is there a steady component or is its origin always intermittent in nature? Where does the heliospheric current sheet form and how stable is it close to the Sun? What is the distribution of CME origins and is there a continuum from large CMEs to small blobs of plasma? We will describe our current knowledge and discuss how SPP and SO will contribute to a more comprehensive understanding of the sources of the solar wind and magnetic fields in the heliosphere.

  13. Q2/Q3 2016 Solar Industry Update

    SciTech Connect

    Feldman, David; Boff, Daniel; Margolis, Robert

    2016-10-11

    This technical presentation provides an update on the major trends that occurred in the solar industry in the Q2 and Q3 of 2016. Major topics of focus include global and U.S. supply and demand, module and system price, investment trends and business models, and updates on U.S. government programs supporting the solar industry.

  14. Q3/Q4 2016 Solar Industry Update

    SciTech Connect

    Feldman, David; Boff, Daniel; Margolis, Robert

    2016-12-21

    This technical presentation provides an update on the major trends that occurred in the solar industry in the Q3 and Q4 of 2016. Major topics of focus include global and U.S. supply and demand, module and system price, investment trends and business models, and updates on U.S. government programs supporting the solar industry.

  15. 3D ELECTRON DENSITY DISTRIBUTIONS IN THE SOLAR CORONA DURING SOLAR MINIMA: ASSESSMENT FOR MORE REALISTIC SOLAR WIND MODELING

    SciTech Connect

    Patoul, Judith de; Foullon, Claire; Riley, Pete E-mail: c.foullon@exeter.ac.uk

    2015-11-20

    Knowledge of the electron density distribution in the solar corona put constraints on the magnetic field configurations for coronal modeling and on initial conditions for solar wind modeling. We work with polarized SOHO/LASCO-C2 images from the last two recent minima of solar activity (1996–1997 and 2008–2010), devoid of coronal mass ejections. The goals are to derive the 4D electron density distributions in the corona by applying a newly developed time-dependent tomographic reconstruction method and to compare the results between the two solar minima and with two magnetohydrodynamic models. First, we confirm that the values of the density distribution in thermodynamic models are more realistic than in polytropic ones. The tomography provides more accurate distributions in the polar regions, and we find that the density in tomographic and thermodynamic solutions varies with the solar cycle in both polar and equatorial regions. Second, we find that the highest-density structures do not always correspond to the predicted large-scale heliospheric current sheet or its helmet streamer but can follow the locations of pseudo-streamers. We deduce that tomography offers reliable density distributions in the corona, reproducing the slow time evolution of coronal structures, without prior knowledge of the coronal magnetic field over a full rotation. Finally, we suggest that the highest-density structures show a differential rotation well above the surface depending on how they are magnetically connected to the surface. Such valuable information on the rotation of large-scale structures could help to connect the sources of the solar wind to their in situ counterparts in future missions such as Solar Orbiter and Solar Probe Plus.

  16. Fermion masses in the economical 3-3-1 model

    SciTech Connect

    Dong, P. V.; Huong, Tr. T.; Huong, D. T.; Long, H. N.

    2006-09-01

    We show that, in frameworks of the economical 3-3-1 model, all fermions get masses. At the tree level, one up-quark and two down-quarks are massless, but the one-loop corrections give all quarks the consistent masses. This conclusion is in contradiction to the previous analysis in which the third scalar triplet has been introduced. This result is based on the key properties of the model: First, there are three quite different scales of vacuum expectation values: {omega}{approx}O(1) TeV, v{approx_equal}246 GeV, and u{approx}O(1) GeV. Second, there exist two types of Yukawa couplings with different strengths: the lepton-number conserving couplings h's and the lepton-number violating ones s's satisfying the condition in which the second are much smaller than the first ones: s<masses of the exotic quarks also have different scales, namely, the U exotic quark (q{sub U}=2/3) gains mass m{sub U}{approx_equal}700 GeV, while the D{sub {alpha}} exotic quarks (q{sub D{sub {alpha}}}=-1/3) have masses in the TeV scale: m{sub D{sub {alpha}}}(set-membership sign)10-80 TeV.

  17. Ionization states of helium in He-3-rich solar energetic particle events

    NASA Technical Reports Server (NTRS)

    Klecker, B.; Hovestadt, D.; Moebius, E.; Scholer, M.; Gloeckler, G.; Ipavich, F. M.

    1983-01-01

    Results of a systematic study of the ionic charge state of helium in the energy range 0.6-1.0 MeV/nucleon for He-3-rich solar energetic particle events during the time period August 1978 to October 1979 are reported. The data have been obtained with the Max-Planck-Institut/University of Maryland experiment on ISEE-3. Whereas for solar energetic particle events with no enrichment of He-3 relative to He-4 surprisingly large abundances of singly ionized helium have been reported recently, He-3-rich solar energetic particle events do not show significant abundances of He-3(+). This result is consistent with current theories explaining large compositional anomalies by mass per charge dependent selective heating of the minor ion species.

  18. Solar POWER-UP: Year 3

    SciTech Connect

    Halverson, K.F.; Maddox, J.; Hoffner, J.; Libby, L.; Noto, V.; Norsworthy, L.

    1995-11-01

    Solar POWER-UP, an educational program that introduces fifth grade students to photovoltaics, is in its third year and has enjoyed successful pilot testing in three states. Students in New Mexico, Louisiana and Texas have experienced the hands-on science project that requires them to work in cooperative teams designing and building solar-powered model race cars. Each school has adapted the program to suite the needs of its students. Maximum use and reuse of components are built into the project. An integral part of this project is the close working partnership developed among classroom teachers and engineers who assist in technical aspects of the unit.

  19. Dynamic model of heat and mass transfer in rectangular adsorber of a solar adsorption machine

    NASA Astrophysics Data System (ADS)

    Chekirou, W.; Boukheit, N.; Karaali, A.

    2016-10-01

    This paper presents the study of a rectangular adsorber of solar adsorption cooling machine. The modeling and the analysis of the adsorber are the key point of such studies; because of the complex coupled heat and mass transfer phenomena that occur during the working cycle. The adsorber is heated by solar energy and contains a porous medium constituted of activated carbon AC-35 reacting by adsorption with methanol. To study the solar collector type effect on system's performances, the used model takes into account the variation of ambient temperature and solar intensity along a simulated day, corresponding to a total daily insolation of 26.12 MJ/m2 with ambient temperature average of 27.7 °C, which is useful to know the daily thermal behavior of the rectangular adsorber.

  20. Models of material ejection. [of solar coronal mass

    NASA Technical Reports Server (NTRS)

    Steinolfson, R. S.

    1990-01-01

    Some recently developed models related to the formation of a coronal mass ejection (CME) are reviewed. The models individually consider the stability of a prominence, the eruption of a coupled prominence and CME configuration with driven reconnection below the prominence, magnetic arcade equilibrium, and coronal evolution due to shear motion. No effort is made to critique the various models. Their relevance to actual observed material ejections will ultimately be determined by detailed comparison with present and future observations.

  1. Destruction of Sun-grazing comet C/2011 N3 (SOHO) within the low solar corona.

    PubMed

    Schrijver, C J; Brown, J C; Battams, K; Saint-Hilaire, P; Liu, W; Hudson, H; Pesnell, W D

    2012-01-20

    Observations of comets in Sun-grazing orbits that survive solar insolation long enough to penetrate into the Sun's inner corona provide information on the solar atmosphere and magnetic field as well as on the makeup of the comet. On 6 July 2011, the Solar Dynamics Observatory (SDO) observed the demise of comet C/2011 N3 (SOHO) within the low solar corona in five wavelength bands in the extreme ultraviolet (EUV). The comet penetrated to within 0.146 solar radius (~100,000 kilometers) of the solar surface before its EUV signal disappeared. Before that, material released into the coma--at first seen in absorption--formed a variable EUV-bright tail. During the final 10 minutes of observation by SDO's Atmospheric Imaging Assembly, ~6 × 10(8) to 6 × 10(10) grams of total mass was lost (corresponding to an effective nucleus diameter of ~10 to 50 meters), as estimated from the tail's deceleration due to interaction with the surrounding coronal material; the EUV absorption by the comet and the brightness of the tail suggest that the mass was at the high end of this range. These observations provide evidence that the nucleus had broken up into a family of fragments, resulting in accelerated sublimation in the Sun's intense radiation field.

  2. 4-Neutrino mass schemes and the likelihood of (3+1)-mass spectra

    NASA Astrophysics Data System (ADS)

    Grimus, W.; Schwetz, T.

    2001-04-01

    We examine the (3+1)-class of 4-neutrino mass spectra within a rigorous statistical analysis based on the Bayesian approach to probability. The data of the Bugey, CDHS and KARMEN experiments are combined by using a likelihood function. Our statistical approach allows us to incorporate solar and atmospheric neutrino data and also the result of the CHOOZ experiment via inequalities which involve elements of the neutrino mixing matrix and are derived from these data. For any short-baseline Δ m^2 we calculate a bound on the LSND transition amplitude A_{μ;e} and find that, in the Δ m^2 A_{μ;e} plane, there is no overlap between the 99% CL region allowed by the latest LSND analysis and the region allowed by our bound on A_{μ;e} at 95% CL; there are some small overlap regions if we take the bound at 99% CL. Therefore, we conclude that, with the existing data, the (3+1)-neutrino mass spectra are not very likely. However, treating the (2+2)-spectra with our method, we find that they are well compatible with all data.

  3. The ARA Mark 3 solar array design and development

    NASA Technical Reports Server (NTRS)

    vanHassel, Rob H. A.

    1996-01-01

    The ARA (Advanced Rigid Array) Mark3 solar array of Fokker Space BV is currently in its final stages of qualification (wing tests to be completed in March, 1996; unit/part tests in April, 1996). With regard to its predecessor, the ARA Mark2, the design has not only been improved in terms of mechanical and electrical performance, but also with regard to production cost and throughput time. This 'state of the art' array is designed to fit the needs of a wide variety of geostationary telecommunications satellites and is qualified for launch on the complete range of medium/large size commercial launchers (Ariane IV & V, Atlas, Delta, Proton, Long March, H2). The first mission to fly the new ARA Mk3 array is Hot Bird 2 (customer: Eutelsat, prime contractor: Matra Marconi Space; launch: mid-1996). In this configuration, its end of life (EOL) power-to-mass ratio is 42 W/kg, with an operational life of more than 12 years. The main mechanisms on a solar array are typically found in the deployment system and in the hold down and release system. During the design and development phase of these mechanisms, extensive engineering and qualification tests have been performed. This paper presents the key design features of these mechanisms and the improvements that were made with regard to their predecessors. It also describes the qualification philosophy on unit/part and wing level. Finally, some of the development items that turned out to be critical, as well as the lessons learned from them, are discussed.

  4. The ARA Mark 3 solar array design and development

    SciTech Connect

    Vanhassel, R.H.A.

    1996-05-01

    The ARA (Advanced Rigid Array) Mark 3 solar array of Fokker Space BV is currently in its final stages of qualification (wing tests to be completed in March, 1996; unit/part tests in April, 1996). With regard to its predecessor, the ARA Mark 2, the design has not only been improved in terms of mechanical and electrical performance, but also with regard to production cost and throughput time. This `state of the art` array is designed to fit the needs of a wide variety of geostationary telecommunications satellites and is qualified for launch on the complete range of medium/large size commercial launchers (Ariane IV & V, Atlas, Delta, Proton, Long March, H2). The first mission to fly the new ARA Mk3 array is Hot Bird 2 (customer: Eutelsat, prime contractor: Matra Marconi Space; launch: mid-1996). In this configuration, its end of life (EOL) power-to-mass ratio is 42 W/kg, with an operational life of more than 12 years. The main mechanisms on a solar array are typically found in the deployment system and in the hold down and release system. During the design and development phase of these mechanisms, extensive engineering and qualification tests have been performed. This paper presents the key design features of these mechanisms and the improvements that were made with regard to their predecessors. It also describes the qualification philosophy on unit/part and wing level. Finally, some of the development items that turned out to be critical, as well as the lessons learned from them, are discussed.

  5. Interactions of Dust Grains with Coronal Mass Ejections and Solar Cycle Variations of the F-Coronal Brightness

    NASA Astrophysics Data System (ADS)

    Ragot, B. R.; Kahler, S. W.

    2003-09-01

    The density of interplanetary dust increases sunward to reach its maximum in the F corona, where its scattered white-light emission dominates that of the electron K corona above about 3 Rsolar. The dust will interact with both the particles and fields of antisunward propagating coronal mass ejections (CMEs). To understand the effects of the CME/dust interactions we consider the dominant forces, with and without CMEs, acting on the dust in the 3-5 Rsolar region. Dust grain orbits are then computed to compare the drift rates from 5 to 3 Rsolar for periods of minimum and maximum solar activity, where a simple CME model is adopted to distinguish between the two periods. The ion-drag force, even in the quiet solar wind, reduces the drift time by a significant factor from its value estimated with the Poynting-Robertson drag force alone. The ion-drag effects of CMEs result in even shorter drift times of the large (>~3 μm) dust grains, hence faster depletion rates and lower dust-grain densities, at solar maxima. If dominated by thermal emission, the near-infrared brightness will thus display solar cycle variations close to the dust plane of symmetry. While trapping the smallest of the grains, the CME magnetic fields also scatter the grains of intermediate size (0.1-3 μm) in latitude. If light scattering by small grains close to the Sun dominates the optical brightness, the scattering by the CME magnetic fields will result in a solar cycle variation of the optical brightness distribution not exceeding 10% at high latitudes, with a higher isotropy reached at solar maxima. A good degree of latitudinal isotropy is already reached at low solar activity since the magnetic fields of the quiet solar wind so close to the Sun are able to scatter the small (<~3 μm) grains up to the polar regions in only a few days or less, producing strong perturbations of their trajectories in less than half their orbital periods. Finally, we consider possible observable consequences of

  6. HAT-P-26b: A Neptune-mass Exoplanet with Primordial Solar Heavy Element Abundance

    NASA Astrophysics Data System (ADS)

    Wakeford, Hannah; Sing, David; Deming, Drake; Kataria, Tiffany; Lopez, Eric

    2016-10-01

    A trend in giant planet mass and atmospheric heavy elemental abundance was first noted last century from observations of planets in our own solar system. These four data points from Jupiter, Saturn, Uranus, and Neptune have served as a corner stone of planet formation theory. Here we add another point in the mass-metallicity trend from a detailed observational study of the extrasolar planet HAT-P-26b, which inhabits the critical mass regime near Neptune and Uranus. Neptune-sized worlds are among the most common planets in our galaxy and frequently exist in orbital periods very different from that of our own solar system ice giants. Atmospheric studies are the principal window into these worlds, and thereby into their formation and evolution, beyond those of our own solar system. Using the Hubble Space Telescope and Spitzer, from the optical to the infrared, we conducted a detailed atmospheric study of the Neptune-mass exoplanet HAT-P-26b over 0.5 to 4.5 μm. We detect prominent H2O absorption at 1.4 μm to 525 ppm in the atmospheric transmission spectrum. We determine that HAT-P-26b's atmosphere is not rich in heavy elements (≈1.8×solar), which goes distinctly against the solar system mass-metallicity trend. This likely indicates that HAT-P-26b's atmosphere is primordial and obtained its gaseous envelope late in its disk lifetime with little contamination from metal-rich planetesimals.

  7. HAT-P-26b: A Neptune-mass Exoplanet with Primordial Solar Heavy Element Abundance

    NASA Astrophysics Data System (ADS)

    Wakeford, Hannah R.; Sing, David K.; Kataria, Tiffany; Deming, Drake; Nikolov, Nikolay; Lopez, Eric; Tremblin, Pascal; Skalid Amundsen, David; Lewis, Nikole K.; Mandell, Avi; Fortney, Jonathan J.; Knutson, Heather; Benneke, Björn; Evans, Tom M.

    2017-01-01

    A trend in giant planet mass and atmospheric heavy elemental abundance was first noted last century from observations of planets in our own solar system. These four data points from Jupiter, Saturn, Uranus, and Neptune have served as a corner stone of planet formation theory. Here we add another point in the mass-metallicity trend from a detailed observational study of the extrasolar planet HAT-P-26b, which inhabits the critical mass regime near Neptune and Uranus. Neptune-sized worlds are among the most common planets in our galaxy and frequently exist in orbital periods very different from that of our own solar system ice giants. Atmospheric studies are the principal window into these worlds, and thereby into their formation and evolution, beyond those of our own solar system. Using the Hubble Space Telescope and Spitzer, from the optical to the infrared, we conducted a detailed atmospheric study of the Neptune-mass exoplanet HAT-P-26b over 0.5 to 4.5 μm. We detect prominent H2O absorption at 1.4 μm to 525 ppm in the atmospheric transmission spectrum. We determine that HAT-P-26b’s atmosphere is not rich in heavy elements (≈1.8×solar), which goes distinctly against the solar system mass-metallicity trend. This likely indicates that HAT-P-26b’s atmosphere is primordial and obtained its gaseous envelope late in its disk lifetime with little contamination from metal-rich planetesimals.

  8. A 2000 Solar Mass Rotating Molecular Disk Around NGC 6334A

    NASA Technical Reports Server (NTRS)

    Kraemer, Kathleen E.; Jackson, James M.; Paglione, A. D.; Bolatto, Alberto D.

    1997-01-01

    We present millimeter and centimeter wave spectroscopic observations of the H II region NGC 6334A. We have mapped the source in several transitions of CO, CS, and NH3. The molecular emission shows a distinct flattened structure in the east-west direction. This structure is probably a thick molecular disk or torus (2.2 x 0.9 pc) responsible for the bipolarity of the near-infrared (NIR) and radio continuum emission which extends in two "lobes" to the north and south of the shell-like H II region. The molecular disk is rotating from west to east (omega approximately equals 2.4 km/s.pc) about an axis approximately parallel to the radio and NIR emission lobes. By assuming virial equilibrium, we find that the molecular disk contains approximately 2000 solar mass. Single-component gas excitation model calculations show that the molecular gas in the disk is warmer and denser (T(sub k) approximately equals 60 K, n approximately equals 3000/cc) than the gas to the north and south (T(sub k) approximately equals 50 K, n approximately equals 400/cc). High resolution (approximately 5 sec) NH3 (3, 3) images of NGC 6334A reveal several small (approximately 0.1 pc) clumps, one of which lies southwest of the radio continuum shell, and is spatially coincident with a near-infrared source, IRS 20. A second NH3 clump is coincident with an H2O maser and the center of a molecular outflow. The dense gas tracers, CS J = 5 approaches 4 and 7 approaches 6, peak near IRS 20 and the H2O maser, not at NGC 6334A. IRS 20 has a substantial far-infrared (FIR) luminosity L(sub FIR) approximately 10(exp 5) solar luminosity, which indicates the presence of an O 7.5 star but has no detected radio continuum (F(sub 6 cm) < 0.02 Jy). The combination of dense gas, a large FIR luminosity and a lack of radio continuum can best be explained if IRS 20 is a protostar. A third clump of NH3 emission lies to the west of IRS 20 but is not associated with any other molecular or continuum features. The star formation

  9. Mass breakdown model of solar-photon sail shuttle: The case for Mars

    NASA Astrophysics Data System (ADS)

    Vulpetti, Giovanni; Circi, Christian

    2016-02-01

    The main aim of this paper is to set up a many-parameter model of mass breakdown to be applied to a reusable Earth-Mars-Earth solar-photon sail shuttle, and analyze the system behavior in two sub-problems: (1) the zero-payload shuttle, and (2) given the sailcraft sail loading and the gross payload mass, find the sail area of the shuttle. The solution to the subproblem-1 is of technological and programmatic importance. The general analysis of subproblem-2 is presented as a function of the sail side length, system mass, sail loading and thickness. In addition to the behaviors of the main system masses, useful information for future work on the sailcraft trajectory optimization is obtained via (a) a detailed mass model for the descent/ascent Martian Excursion Module, and (b) the fifty-fifty solution to the sailcraft sail loading breakdown equation. Of considerable importance is the evaluation of the minimum altitude for the rendezvous between the ascent rocket vehicle and the solar-photon sail propulsion module, a task performed via the Mars Climate Database 2014-2015. The analysis shows that such altitude is 300 km; below it, the atmospheric drag prevails over the solar-radiation thrust. By this value, an example of excursion module of 1500 kg in total mass is built, and the sailcraft sail loading and the return payload are calculated. Finally, the concept of launch opportunity-wide for a shuttle driven by solar-photon sail is introduced. The previous fifty-fifty solution may be a good initial guess for the trajectory optimization of this type of shuttle.

  10. Impurity characterization of solar wind collectors for the genesis discovery mission by resonance ionization mass spectrometry.

    SciTech Connect

    Calaway, W. F.

    1999-02-01

    NASA's Genesis Discovery Mission is designed to collect solar matter and return it to earth for analysis. The mission consists of launching a spacecraft that carries high purity collector materials, inserting the spacecraft into a halo orbit about the L1 sun-earth libration point, exposing the collectors to the solar wind for two years, and then returning the collectors to earth. The collectors will then be made available for analysis by various methods to determine the elemental and isotopic abundance of the solar wind. In preparation for this mission, potential collector materials are being characterized to determine baseline impurity levels and to assess detection limits for various analysis techniques. As part of the effort, potential solar wind collector materials have been analyzed using resonance ionization mass spectrometry (RIMS). RIMS is a particularly sensitivity variation of secondary neutral mass spectrometry that employs resonantly enhanced multiphoton ionization (REMPI) to selectively postionize an element of interest, and thus discriminates between low levels of that element and the bulk material. The high sensitivity and selectivity of RIMS allow detection of very low concentrations while consuming only small amounts of sample. Thus, RIMS is well suited for detection of many heavy elements in the solar wind, since metals heavier than Fe are expected to range in concentrations from 1 ppm to 0.2 ppt. In addition, RIMS will be able to determine concentration profiles as a function of depth for these implanted solar wind elements effectively separating them from terrestrial contaminants. RIMS analyses to determine Ti concentrations in Si and Ge samples have been measured. Results indicate that the detection limit for RIMS analysis of Ti is below 100 ppt for 10{sup 6} averages. Background analyses of the mass spectra indicate that detection limits for heavier elements will be similar. Furthermore, detection limits near 1 ppt are possible with higher

  11. Energy efficiency and comfort conditions in passive solar buildings: Effect of thermal mass at equatorial high altitudes

    NASA Astrophysics Data System (ADS)

    Ogoli, David Mwale

    This dissertation is based on the philosophy that architectural design should not just be a function of aesthetics, but also of energy-efficiency, advanced technologies and passive solar strategies. A lot of published literature is silent regarding buildings in equatorial highland regions. This dissertation is part of the body of knowledge that attempts to provide a study of energy in buildings using thermal mass. The objectives were to establish (1) effect of equatorial high-altitude climate on thermal mass, (2) effect of thermal mass on moderating indoor temperatures, (3) effect of thermal mass in reducing heating and cooling energy, and (4) the amount of time lag and decrement factor of thermal mass. Evidence to analyze the effect of thermal mass issues came from three sources. First, experimental physical models involving four houses were parametrically conducted in Nairobi, Kenya. Second, energy computations were made using variations in thermal mass for determining annual energy usage and costs. Third, the data gathered were observed, evaluated, and compared with currently published research. The findings showed that: (1) Equatorial high-altitude climates that have diurnal temperature ranging about 10--15°C allow thermal mass to moderate indoor temperatures; (2) Several equations were established that indicate that indoor mean radiant temperatures can be predicted from outdoor temperatures; (3) Thermal mass can reduce annual energy for heating and cooling by about 71%; (4) Time lag and decrement of 200mm thick stone and concrete thermal mass can be predicted by a new formula; (5) All windows on a building should be shaded. East and west windows when shaded save 51% of the cooling energy. North and south windows when fully shaded account for a further 26% of the cooling energy; (6) Insulation on the outside of a wall reduces energy use by about 19.6% below the levels with insulation on the inside. The basic premise of this dissertation is that decisions that

  12. Solar flare associated coronal mass ejections causing geo-effectiveness and Forbush decreases

    NASA Astrophysics Data System (ADS)

    Bhatt, Beena; Chandra, Harish

    2017-02-01

    In the present study, we have selected 35 halo Coronal Mass Ejections (CMEs) associated with solar flares, Geomagnetic Storms (GSs) and Forbush decrease (Fd) chosen from 1st January 2000 to 31st December 2007 (i.e., the descending phase of solar cycle 23) observed by the Large Angle Spectrometric Coronagraph (LASCO) on board the SOHO spacecraft. Statistical analyses are performed to look at the distribution of solar flares associated with halo CMEs causing GSs and Fd and investigated the relationship between solar flare and halo CME parameters with GSs and Fd. Forbush decrease is the phenomenon of rapid decrease in cosmic ray intensity following the CME. Our analysis indicates that during 2000 to 2007 the northern region produced 44 % of solar flares associated with halo CMEs, GSs, and Fd, whereas 56 % solar flares associated with halo CMEs, GSs, and Fd were produced in the southern region. The northern and the southern hemispheres between 10° to 20° latitudinal belts are found to be more effective in producing events leading to Fd. From our selected events, we found that about 60 % of super-intense storms (Dst ≤ -200 nT) caused by halo CMEs are associated with X-class flares. Fast halo CMEs associated with X-class flares originating from 0° to 25° latitudes are better potential candidates in producing super-intense GSs than the slow halo CMEs associated with other classes of flares.

  13. Identification of Interplanetary Coronal Mass Ejections at 1 AU Using Multiple Solar Wind Plasma Composition Anomalies

    NASA Technical Reports Server (NTRS)

    Richardson, I. G.; Cane, H. V.

    2004-01-01

    We investigate the use of multiple simultaneous solar wind plasma compositional anomalies, relative to the composition of the ambient solar wind, for identifying interplanetary coronal mass ejection (ICME) plasma. We first summarize the characteristics of several solar wind plasma composition signatures (O(+7)/O(+6), Mg/O, Ne/O, Fe charge states, He/p) observed by the ACE and WIND spacecraft within the ICMEs during 1996 - 2002 identsed by Cane and Richardson. We then develop a set of simple criteria that may be used to identify such compositional anomalies, and hence potential ICMEs. To distinguish these anomalies from the normal variations seen in ambient solar wind composition, which depend on the wind speed, we compare observed compositional signatures with those 'expected' in ambient solar wind with the same solar wind speed. This method identifies anomalies more effectively than the use of fixed thresholds. The occurrence rates of individual composition anomalies within ICMEs range from approx. 70% for enhanced iron and oxygen charge states to approx. 30% for enhanced He/p (> 0.06) and Ne/O, and are generally higher in magnetic clouds than other ICMEs. Intervals of multiple anomalies are usually associated with ICMEs, and provide a basis for the identification of the majority of ICMEs. We estimate that Cane and Richardson, who did not refer to composition data, probably identitied approx. 90% of the ICMEs present. However, around 10% of their ICMEs have weak compositional anomalies, suggesting that the presence of such signatures does not provide a necessary requirement for an ICME. We note a remarkably similar correlation between the Mg/O and O(7)/O(6) ratios in hourly-averaged data both within ICMEs and the ambient solar wind. This 'universal' relationship suggests that a similar process (such as minor ion heating by waves inside coronal magnetic field loops) produces the first-ionization potential bias and ion freezing-in temperatures in the source regions

  14. Advanced Heat/Mass Exchanger Technology for Geothermal and Solar Renewable Energy Systems

    SciTech Connect

    Greiner, Miles; Childress, Amy; Hiibel, Sage; Kim, Kwang; Park, Chanwoo; Wirtz, Richard

    2014-12-16

    Northern Nevada has abundant geothermal and solar energy resources, and these renewable energy sources provide an ample opportunity to produce economically viable power. Heat/mass exchangers are essential components to any energy conversion system. Improvements in the heat/mass exchange process will lead to smaller, less costly (more efficient) systems. There is an emerging heat transfer technology, based on micro/nano/molecular-scale surface science that can be applied to heat/mass exchanger design. The objective is to develop and characterize unique coating materials, surface configurations and membranes capable of accommodating a 10-fold increase in heat/mass exchanger performance via phase change processes (boiling, condensation, etc.) and single phase convective heat/mass transfer.

  15. Coronal mass ejections and other extreme characteristics of the 2003 October-November solar eruptions

    NASA Astrophysics Data System (ADS)

    Gopalswamy, N.; Yashiro, S.; Liu, Y.; Michalek, G.; Vourlidas, A.; Kaiser, M. L.; Howard, R. A.

    2005-09-01

    Fast coronal mass ejections (CMEs), X-class flares, solar energetic particle (SEP) events, and interplanetary shocks were abundantly observed during the episode of intense solar activity in late October and early November 2003. Most of the 80 CMEs originated from three active regions (NOAA ARs 484, 486, and 488). We compare the statistical properties of these CMEs with those of the general population of CMEs observed during cycle 23. We find that (1) the 2003 October-November CMEs were fast and wide on the average and hence were very energetic, (2) nearly 20 percent of the ultrafast CMEs (speed ≥2000 km s-1) of cycle 23 occurred during the October-November interval, including the fastest CME of the study period (˜2700 km s-1 on 4 November 2003 at 1954 UT), (3) the rate of full-halo CMEs was nearly four times the average rate during cycle 23, (4) at least sixteen shocks were observed near the Sun, while eight of them were intercepted by spacecraft along the Sun-Earth line, (5) the CMEs were highly geoeffective: the resulting geomagnetic storms were among the most intense of cycle 23, (6) the CMEs were associated with very large SEP events, including the largest event of cycle 23. These extreme properties were commensurate with the size and energy of the associated active regions. This study suggests that the speed of CMEs may not be much higher than ˜3000 km s-1, consistent with the free energy available in active regions. An important practical implication of such a speed limit is that the Sun-Earth travel times of CME-driven shocks may not be less than ˜0.5 day. Two of the shocks arrived at Earth in <24 hours, the first events in ˜30 years and only the 14th and 15th documented cases of such events since 1859.

  16. TETHER-CUTTING RECONNECTION BETWEEN TWO SOLAR FILAMENTS TRIGGERING OUTFLOWS AND A CORONAL MASS EJECTION

    SciTech Connect

    Chen, Huadong; Zhang, Jun; Li, Leping; Ma, Suli

    2016-02-20

    Triggering mechanisms of solar eruptions have long been a challenge. A few previous case studies have indicated that preceding gentle filament merging via magnetic reconnection may launch following intense eruption, according to the tether-cutting (TC) model. However, the detailed process of TC reconnection between filaments has not been exhibited yet. In this work, we report the high-resolution observations from the Interface Region Imaging Spectrometer (IRIS) of TC reconnection between two sheared filaments in NOAA active region 12146. The TC reconnection commenced on ∼15:35 UT on 2014 August 29 and triggered an eruptive GOES C4.3-class flare ∼8 minutes later. An associated coronal mass ejection appeared in the field of view of the Solar and Heliospheric Observatory/LASCO C2 about 40 minutes later. Thanks to the high spatial resolution of IRIS data, bright plasma outflows generated by the TC reconnection are clearly observed, which moved along the subarcsecond fine-scale flux tube structures in the erupting filament. Based on the imaging and spectral observations, the mean plane-of-sky and line-of-sight velocities of the TC reconnection outflows are separately measured to be ∼79 and 86 km s{sup −1}, which derives an average real speed of ∼120 km s{sup −1}. In addition, it is found that spectral features, such as peak intensities, Doppler shifts, and line widths in the TC reconnection region are evidently enhanced compared to those in the nearby region just before the flare.

  17. Intense Pulsed Light Sintering of CH3NH3PbI3 Solar Cells.

    PubMed

    Lavery, Brandon W; Kumari, Sudesh; Konermann, Hannah; Draper, Gabriel L; Spurgeon, Joshua; Druffel, Thad

    2016-04-06

    Perovskite solar cells utilizing a two-step deposited CH3NH3PbI3 thin film were rapidly sintered using an intense pulsed light source. For the first time, a heat treatment has shown the capability of sintering methylammonium lead iodide perovskite and creating large crystal sizes approaching 1 μm without sacrificing surface coverage. Solar cells with an average efficiency of 11.5% and a champion device of 12.3% are reported. The methylammonium lead iodide perovskite was subjected to 2000 J of energy in a 2 ms pulse of light generated by a xenon lamp, resulting in temperatures significantly exceeding the degradation temperature of 150 °C. The process opens up new opportunities in the manufacturability of perovskite solar cells by eliminating the rate-limiting annealing step, and makes it possible to envision a continuous roll-to-roll process similar to the printing press used in the newspaper industry.

  18. Analysis of Epsilon Aurigae light curve from the Solar Mass Ejection Imager

    NASA Astrophysics Data System (ADS)

    Clover, John; Jackson, B. V.; Buffington, A.; Hick, P. P.; Kloppenborg, B.; Stencel, R.

    2011-01-01

    The Solar Mass Ejection Imager (SMEI) was launched aboard the Coriolis spacecraft in 2003. It is equipped with 3 CCD cameras to measure the brightness of Thomson-scattered electrons in the heliosphere. Each CCD images a strip of the sky that is 3°x60°. The three cameras are mounted on the satellite with their fields of view aligned end-to-end so that SMEI sweeps nearly the entire sky each 102 minute orbit. SMEI has now accumulated stellar time series for about 5700 bright stars, including epsilon Aurigae, for each orbit where data is available. SMEI data provide nearly year-round coverage of epsilon Aurigae. The baffled SMEI optics provide more accurate photometric data than ground-based observations, particularly at mid-eclipse when epsilon Aurigae is close to the Sun. We present an analysis of the brightness variations of the epsilon Aurigae system, before and during the eclipse. The University of Denver participants are grateful for support under NSFgrant 10-16678 and the bequest of William Hershel Womble in support of astronomy at the University of Denver.

  19. Analysis of ISEE-3/ICE solar wind data

    NASA Technical Reports Server (NTRS)

    Coplan, Michael A.

    1989-01-01

    Under the grant that ended November 11, 1988 work was accomplished in a number of areas, as follows: (1) Analysis of solar wind data; (2) Analysis of Giacobini/Zinner encounter data; (3) Investigation of solar wind and magnetospheric electron velocity distributions; and (4) Experimental investigation of the electronic structure of clusters. Reprints and preprints of publications resulting from this work are included in the appendices.

  20. Anomalous Expansion of Coronal Mass Ejections During Solar Cycle 24 and Its Space Weather Implications

    NASA Technical Reports Server (NTRS)

    Gopalswamy, Nat; Akiyama, Sachiko; Yashiro, Seiji; Xie, Hong; Makela, Pertti; Michalek, Grzegorz

    2014-01-01

    The familiar correlation between the speed and angular width of coronal mass ejections (CMEs) is also found in solar cycle 24, but the regression line has a larger slope: for a given CME speed, cycle 24 CMEs are significantly wider than those in cycle 23. The slope change indicates a significant change in the physical state of the heliosphere, due to the weak solar activity. The total pressure in the heliosphere (magnetic + plasma) is reduced by approximately 40%, which leads to the anomalous expansion of CMEs explaining the increased slope. The excess CME expansion contributes to the diminished effectiveness of CMEs in producing magnetic storms during cycle 24, both because the magnetic content of the CMEs is diluted and also because of the weaker ambient fields. The reduced magnetic field in the heliosphere may contribute to the lack of solar energetic particles accelerated to very high energies during this cycle.

  1. Identification of Interplanetary Coronal Mass Ejections at Ulysses Using Multiple Solar Wind Signatures

    NASA Astrophysics Data System (ADS)

    Richardson, I. G.

    2014-10-01

    Previous studies have discussed the identification of interplanetary coronal mass ejections (ICMEs) near the Earth based on various solar wind signatures. In particular, methods have been developed of identifying regions of anomalously low solar wind proton temperatures ( T p) and plasma compositional anomalies relative to the composition of the ambient solar wind that are frequently indicative of ICMEs. In this study, similar methods are applied to observations from the Ulysses spacecraft that was launched in 1990 and placed in a heliocentric orbit over the poles of the Sun. Some 279 probable ICMEs are identified during the spacecraft mission, which ended in 2009. The identifications complement those found independently in other studies of the Ulysses data, but a number of additional events are identified. The properties of the ICMEs detected at Ulysses and those observed near the Earth and in the inner heliosphere are compared.

  2. General working principles of CH3NH3PbX3 perovskite solar cells.

    PubMed

    Gonzalez-Pedro, Victoria; Juarez-Perez, Emilio J; Arsyad, Waode-Sukmawati; Barea, Eva M; Fabregat-Santiago, Francisco; Mora-Sero, Ivan; Bisquert, Juan

    2014-02-12

    Organometal halide perovskite-based solar cells have recently realized large conversion efficiency over 15% showing great promise for a new large scale cost-competitive photovoltaic technology. Using impedance spectroscopy measurements we are able to separate the physical parameters of carrier transport and recombination in working devices of the two principal morphologies and compositions of perovskite solar cells, viz. compact thin films of CH3NH3PbI(3-x)Clx and CH3NH3PbI3 infiltrated on nanostructured TiO2. The results show nearly identical spectral characteristics indicating a unique photovoltaic operating mechanism that provides long diffusion lengths (1 μm). Carrier conductivity in both devices is closely matched, so that the most significant differences in performance are attributed to recombination rates. These results highlight the central role of the CH3NH3PbX3 semiconductor absorber in carrier collection and provide a new tool for improved optimization of perovskite solar cells. We report for the first time a measurement of the diffusion length in a nanostructured perovskite solar cell.

  3. Geodynamo, solar wind, and magnetopause 3.4 to 3.45 billion years ago.

    PubMed

    Tarduno, John A; Cottrell, Rory D; Watkeys, Michael K; Hofmann, Axel; Doubrovine, Pavel V; Mamajek, Eric E; Liu, Dunji; Sibeck, David G; Neukirch, Levi P; Usui, Yoichi

    2010-03-05

    Stellar wind standoff by a planetary magnetic field prevents atmospheric erosion and water loss. Although the early Earth retained its water and atmosphere, and thus evolved as a habitable planet, little is known about Earth's magnetic field strength during that time. We report paleointensity results from single silicate crystals bearing magnetic inclusions that record a geodynamo 3.4 to 3.45 billion years ago. The measured field strength is approximately 50 to 70% that of the present-day field. When combined with a greater Paleoarchean solar wind pressure, the paleofield strength data suggest steady-state magnetopause standoff distances of < or = 5 Earth radii, similar to values observed during recent coronal mass ejection events. The data also suggest lower-latitude aurora and increases in polar cap area, as well as heating, expansion, and volatile loss from the exosphere that would have affected long-term atmospheric composition.

  4. Ion composition experiment. [ISEE-C solar wind ion mass spectroscopy

    NASA Technical Reports Server (NTRS)

    Coplan, M. A.; Ogilvie, K. W.; Bochsler, P. A.; Geiss, J.

    1978-01-01

    An investigation using a novel ion mass spectrometer for measuring the ionic composition of the solar wind from the ISEE-C spacecraft is described. The resolution and dynamic range of the instrument are sufficient to be able to resolve up to twelve individual ions or groups of ions. This will permit the solution of a number of fundamental problems related to solar abundances and the formation of the solar wind. The spectrometer is composed of a stigmatic Wien filter and hemispherical electrostatic energy analyzer. The use of curved electric field plates in the filter results in a substantial saving of weight with respect to a conventional filter of the same resolution and angular acceptance. The spectrometer is controlled by a microprocessor based on a special purpose computer which has three modes of operations: full and partial survey modes and a search mode. In the search mode, the instrument locks on to the solar wind. This allows four times the time resolution of the full survey mode and yields a full mass spectrum every 12.6 min.

  5. FINE MAGNETIC STRUCTURE AND ORIGIN OF COUNTER-STREAMING MASS FLOWS IN A QUIESCENT SOLAR PROMINENCE

    SciTech Connect

    Shen, Yuandeng; Liu, Yu; Xu, Zhi; Liu, Zhong; Liu, Ying D.; Chen, P. F.; Su, Jiangtao

    2015-11-20

    We present high-resolution observations of a quiescent solar prominence that consists of a vertical and a horizontal foot encircled by an overlying spine and has ubiquitous counter-streaming mass flows. While the horizontal foot and the spine were connected to the solar surface, the vertical foot was suspended above the solar surface and was supported by a semicircular bubble structure. The bubble first collapsed, then reformed at a similar height, and finally started to oscillate for a long time. We find that the collapse and oscillation of the bubble boundary were tightly associated with a flare-like feature located at the bottom of the bubble. Based on the observational results, we propose that the prominence should be composed of an overlying horizontal spine encircling a low-lying horizontal and vertical foot, in which the horizontal foot consists of shorter field lines running partially along the spine and has ends connected to the solar surface, while the vertical foot consists of piling-up dips due to the sagging of the spine fields and is supported by a bipolar magnetic system formed by parasitic polarities (i.e., the bubble). The upflows in the vertical foot were possibly caused by the magnetic reconnection at the separator between the bubble and the overlying dips, which intruded into the persistent downflow field and formed the picture of counter-streaming mass flows. In addition, the counter-streaming flows in the horizontal foot were possibly caused by the imbalanced pressure at the both ends.

  6. Understanding the Global Structure and Evolution of Coronal Mass Ejections in the Solar Wind

    NASA Technical Reports Server (NTRS)

    Riley, Pete

    2004-01-01

    This report summarizes the technical progress made during the first six months of the second year of the NASA Living with a Star program contract Understanding the global structure and evolution of coronal mass ejections in the solar wind, between NASA and Science Applications International Corporation, and covers the period November 18, 2003 - May 17,2004. Under this contract SAIC has conducted numerical and data analysis related to fundamental issues concerning the origin, intrinsic properties, global structure, and evolution of coronal mass ejections in the solar wind. During this working period we have focused on a quantitative assessment of 5 flux rope fitting techniques. In the following sections we summarize the main aspects of this work and our proposed investigation plan for the next reporting period. Thus far, our investigation has resulted in 6 refereed scientific publications and we have presented the results at a number of scientific meetings and workshops.

  7. Influence of mass moment of inertia on normal modes of preloaded solar array mast

    NASA Technical Reports Server (NTRS)

    Armand, Sasan C.; Lin, Paul

    1992-01-01

    Earth-orbiting spacecraft often contain solar arrays or antennas supported by a preloaded mast. Because of weight and cost considerations, the structures supporting the spacecraft appendages are extremely light and flexible; therefore, it is vital to investigate the influence of all physical and structural parameters that may influence the dynamic behavior of the overall structure. The study primarily focuses on the mast for the space station solar arrays, but the formulations and the techniques developed in this study apply to any large and flexible mast in zero gravity. Furthermore, to determine the influence on the circular frequencies, the mass moment of inertia of the mast was incorporated into the governing equation of motion for bending. A finite element technique (MSC/NASTRAN) was used to verify the formulation. Results indicate that when the mast is relatively flexible and long, the mass moment inertia influences the circular frequencies.

  8. INTERACTION BETWEEN TWO CORONAL MASS EJECTIONS IN THE 2013 MAY 22 LARGE SOLAR ENERGETIC PARTICLE EVENT

    SciTech Connect

    Ding, Liu-Guan; Xu, Fei; Gu, Bin; Zhang, Ya-Nan; Li, Gang; Jiang, Yong; Le, Gui-Ming; Shen, Cheng-Long; Wang, Yu-Ming; Chen, Yao

    2014-10-01

    We investigate the eruption and interaction of two coronal mass ejections (CMEs) during the large 2013 May 22 solar energetic particle event using multiple spacecraft observations. Two CMEs, having similar propagation directions, were found to erupt from two nearby active regions (ARs), AR11748 and AR11745, at ∼08:48 UT and ∼13:25 UT, respectively. The second CME was faster than the first CME. Using the graduated cylindrical shell model, we reconstructed the propagation of these two CMEs and found that the leading edge of the second CME caught up with the trailing edge of the first CME at a height of ∼6 solar radii. After about two hours, the leading edges of the two CMEs merged at a height of ∼20 solar radii. Type II solar radio bursts showed strong enhancement during this two hour period. Using the velocity dispersion method, we obtained the solar particle release (SPR) time and the path length for energetic electrons. Further assuming that energetic protons propagated along the same interplanetary magnetic field, we also obtained the SPR time for energetic protons, which were close to that of electrons. These release times agreed with the time when the second CME caught up with the trailing edge of the first CME, indicating that the CME-CME interaction (and shock-CME interaction) plays an important role in the process of particle acceleration in this event.

  9. 3D model atmospheres and the solar photospheric oxygen abundance

    NASA Astrophysics Data System (ADS)

    Caffau, E.; Ludwig, H.-G.

    2008-10-01

    In recent years the photospheric solar oxygen abundance experienced a significant downward revision. However, a low photospheric abundance is incompatible with the value in the solar interior inferred from helioseismology. For contributing to the dispute whether the solar oxygen abundance is “high” or “low”, we re-derived its photospheric abundance independently of previous analyses. We applied 3D (CO5BOLD) as well as 1D model atmospheres. We considered standard disc-centre and disc-integrated spectral atlases, as well as newly acquired solar intensity spectra at different heliocentric angles. We determined the oxygen abundances from equivalent width and/or line profile fitting of a number of atomic lines. As preliminary result, we find an oxygen abundance in the range 8.73 8.79, encompassing the value obtained by Holweger (2001), and somewhat higher than the value obtained by Asplund et al. (2005).

  10. Non-mass-analyzed ion implantation equipment for high volume solar cell production

    NASA Technical Reports Server (NTRS)

    Armini, A. J.; Bunker, S. N.; Spitzer, M. B.

    1982-01-01

    Equipment designed for junction formation in silicon solar cells is described. The equipment, designed for a production level of approximately one megawatt per year, consists of an ion implanter and annealer. Low cost is achieved by foregoing the use of mass analysis during the implantation, and by the use of a belt furnace for annealing. Results of process development, machine design and cost analysis are presented.

  11. Solar neutrino limit on axions and keV-mass bosons

    SciTech Connect

    Gondolo, Paolo; Raffelt, Georg G.

    2009-05-15

    The all-flavor solar neutrino flux measured by the Sudbury Neutrino Observatory constrains nonstandard energy losses to less than about 10% of the Sun's photon luminosity, superseding a helioseismological argument and providing new limits on the interaction strength of low-mass particles. For the axion-photon coupling strength we find g{sub a{gamma}}<7x10{sup -10} GeV{sup -1}. We also derive explicit limits on the Yukawa coupling to electrons of pseudoscalar, scalar, and vector bosons with keV-scale masses.

  12. 43 CFR 3106.4-3 - Mass transfers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Mass transfers. 3106.4-3 Section 3106.4-3... or Otherwise § 3106.4-3 Mass transfers. (a) A mass transfer may be utilized in lieu of the provisions... large number of Federal leases to the same transferee. (b) Three originally executed copies of the...

  13. 43 CFR 3106.4-3 - Mass transfers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Mass transfers. 3106.4-3 Section 3106.4-3... or Otherwise § 3106.4-3 Mass transfers. (a) A mass transfer may be utilized in lieu of the provisions... large number of Federal leases to the same transferee. (b) Three originally executed copies of the...

  14. 43 CFR 3106.4-3 - Mass transfers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Mass transfers. 3106.4-3 Section 3106.4-3... or Otherwise § 3106.4-3 Mass transfers. (a) A mass transfer may be utilized in lieu of the provisions... large number of Federal leases to the same transferee. (b) Three originally executed copies of the...

  15. 43 CFR 3106.4-3 - Mass transfers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Mass transfers. 3106.4-3 Section 3106.4-3... or Otherwise § 3106.4-3 Mass transfers. (a) A mass transfer may be utilized in lieu of the provisions... large number of Federal leases to the same transferee. (b) Three originally executed copies of the...

  16. Nonuniform viscosity in the solar nebula and large masses of Jupiter and Saturn

    NASA Astrophysics Data System (ADS)

    Jin, L.

    2004-08-01

    I report a novel theory that nonuniform viscous frictional force in the solar nebula accounts for the largest mass of Jupiter and Saturn and their largest amount of H and He among the planets, two outstanding facts that are unsolved puzzles in our understanding of origin of the Solar System. It is shown that the nebula model of uniform viscosity does not match the present planet masses. By studying current known viscosity mechanisms, I show that viscosity is more efficient in the inner region inside Mercury and the outer region outside Jupiter-Saturn than the intermediate region. The more efficient viscosity drives faster radial inflow of material during the nebula evolution. Because the inflow in the outer region is faster than the intermediate region, the material tends to accumulate in Jupiter-Saturn region which is between the outer and intermediate region. It is demonstrated that the gas trapping time of Jovian planets is longer than the inflow time in the outer region. Therefore the gas already flows to Jupiter-Saturn region before Uranus and Neptune can capture significant gas. But the inflow in the Jupiter-Saturn region is so slow that they can capture large amount of gas before the gas can flow further inward. Hence they have larger masses with larger H and He content than Uranus and Neptune. I also extend the discussion to the masses of the terrestrial planets, especially low mass of Mercury. The advantages of this theory are discussed.

  17. Solar nebula constraints derived from the masses and formation times of Earth, Mars, Jupiter and Saturn

    NASA Astrophysics Data System (ADS)

    Mosqueira, Ignacio; Lichtig, Ryan

    2014-11-01

    Terrestrial planets accreted from the late-stage collisional evolution of planetary embryos (roughly Mars-sized) and leftover planetesimals (Chambers 2013). Since the timescale to produce Earth-like analogues is on the order of ~ 100 My, the solar nebula gas would have dissipated by then. On the other hand, Hf-W chronology yields a short accretion timescale for Mars ~9 My (Dauphas and Pourmand 2011), which is similar to the gas dissipation time (Haisch et al. 2011). The Grand-Tack model proposes that Jupiter and Saturn migrated inward until Saturn was caught in a 2:3 mean motion resonance then migrated outward, truncating the disk in the process and accounting for Mars’ orbit, accretion timescale, and small mass (Walsh et al. 2011). However, in order to power the migration of the giant planets this model assumes the presence of a massive (compared to Jupiter) viscously evolving gas disk. This means that the giant planets themselves would not have completed their growth. Thus, the Grand-Tack model provides an explanation for the small mass of Mars at the cost of ignoring the resulting problematic large mass of Saturn. Here we fix the locations and masses of Jupiter and Saturn and develop a model in which the depleted region is due to three key mechanisms: one, removal of collisional fragments by gas drag; two, coalescence of planetary embryos by sweeping secular resonances during gas disk dispersal; three, removal of planetary embryos by Type I tidal interaction with the gas disk. We use analytical and numerical N-body results to evaluate the consequences of the above processes for the disk of solids. We focus on the variables controlling the extent of the depleted region. We stress that the static giant planets nevertheless play a determining role: first, by filtering-out outer disk planetesimal fragments that would otherwise replenish the inner disk; second, by increasing the (phased) eccentricities of planetary embryos thereby allowing larger objects to form

  18. 3D-HST + CANDELS: the Evolution of the Galaxy Size-mass Distribution Since Z=3

    NASA Technical Reports Server (NTRS)

    VanDerWel, A.; Franx, M.; vanDokkum, P. G.; Skelton, R. E.; Momcheva, I. G.; Whitaker, K. E.; Brammer, G. B.; Bell, E. F.; Rix, H.-W.; Wuyts, S.; Ferguson, H. C.; Holden, B. P.; Barro, G.; Koekemoer, A. M.; Chang, Yu-Yen; McGrath, E. J.; Haussler, B.; Dekel, A.; Behroozi, P.; Fumagalli, M.; Leja, J.; Lundgren, B. F.; Maseda, M. V.; Nelson, E. J.; Wake, D. A.

    2014-01-01

    Spectroscopic and photometric redshifts, stellar mass estimates, and rest-frame colors from the 3D-HST survey are combined with structural parameter measurements from CANDELS imaging to determine the galaxy size-mass distribution over the redshift (z) range 0 < z < 3. Separating early- and late-type galaxies on the basis of star-formation activity, we confirm that early-type galaxies are on average smaller than late-type galaxies at all redshifts, and find a significantly different rate of average size evolution at fixed galaxy mass, with fast evolution for the early-type population, effective radius is in proportion to (1 + z) (sup -1.48), and moderate evolution for the late-type population, effective radius is in proportion to (1 + z) (sup -0.75). The large sample size and dynamic range in both galaxy mass and redshift, in combination with the high fidelity of our measurements due to the extensive use of spectroscopic data, not only fortify previous results, but also enable us to probe beyond simple average galaxy size measurements. At all redshifts the slope of the size-mass relation is shallow, effective radius in proportion to mass of a black hole (sup 0.22), for late-type galaxies with stellar mass > 3 x 10 (sup 9) solar masses, and steep, effective radius in proportion to mass of a black hole (sup 0.75), for early-type galaxies with stellar mass > 2 x 10 (sup 10) solar masses. The intrinsic scatter is approximately or less than 0.2 decimal exponents for all galaxy types and redshifts. For late-type galaxies, the logarithmic size distribution is not symmetric, but skewed toward small sizes: at all redshifts and masses a tail of small late-type galaxies exists that overlaps in size with the early-type galaxy population. The number density of massive (approximately 10 (sup 11) solar masses), compact (effective radius less than 2 kiloparsecs) early-type galaxies increases from z = 3 to z = 1.5 - 2 and then strongly decreases at later cosmic times.

  19. Characteristics of coronal mass ejections associated with solar frontside and backside metric Type II bursts

    NASA Technical Reports Server (NTRS)

    Kahler, S. W.; Cliver, E. W.; Sheeley, N. R.; Howard, R. A.; Michels, D. J.; Koomen, M. J.

    1985-01-01

    Fast velocities of 500 km/s or greater coronal mass ejections (CME's) are compared with reported metric type II bursts to study the properties of CME's associated with coronal shocks. An earlier report of fast frontside CME's with no associated metric type II bursts is confirmed, and it is calculated that 33 + or - 15 percent of all fast frontside CME's are not associated with such bursts. Faster CME's are more likely to be associated with type II bursts, as expected from the hypothesis of piston-driven shocks. However, CME brightness and associated peak 3-cm burst intensity are also important factors, as might be inferred from the Wagner and MacQueen (1983) view of type II shocks decoupled from associated CME's. The equal visibility of solar frontside and backside CME's is used to deduce the observability of backside type II bursts. It is calculated that 23 + or - 7 percent of all backside type II bursts associated with fast CME's can be observed at the earth and that 13 + or - 4 percent of all type II bursts originate in backside flares. CME speed again is the most important factor in the obervability of backside type II bursts.

  20. Modelling the evolution of solar-mass stars with a range of metallicities using MESA

    NASA Astrophysics Data System (ADS)

    Jones, E. F.; Gore, P. M.

    2015-05-01

    The nuclides 1,2H, 3,4He, 7Li, 7Be, 8B, 12,13C, 13-15N, 14-18O, 17-19F, 18-22Ne, 22Mg, and 24Mg were used in the code package MESA (Modules for Experiments in Stellar Astrophysics)[Paxton] to model a one-solar-mass star with a range of metallicities, z, from 0 to 0.1. On HR diagrams of each star model's luminosity and effective temperature from before zero-age main sequence (pre-ZAMS) to white dwarf, oscillations were noted in the horizontal branch at intervals from z = 0 to 0.0070. At z, = 0, the calculated stellar lifetime is 6.09x109 years. The calculated lifetime of the model stars increases to a maximum of 1.25x1010 years at z = 0.022 and then decreases to 2.59x109 years at z = 0.1. A piecewise fit of the model lifetimes vs. metallicity was obtained.

  1. Measuring Solar Radiation Incident on Earth: Solar Constant-3 (SOLCON-3)

    NASA Technical Reports Server (NTRS)

    Crommelynck, Dominique; Joukoff, Alexandre; Dewitte, Steven

    2002-01-01

    Life on Earth is possible because the climate conditions on Earth are relatively mild. One element of the climate on Earth, the temperature, is determined by the heat exchanges between the Earth and its surroundings, outer space. The heat exchanges take place in the form of electromagnetic radiation. The Earth gains energy because it absorbs solar radiation, and it loses energy because it emits thermal infrared radiation to cold space. The heat exchanges are in balance: the heat gained by the Earth through solar radiation equals the heat lost through thermal radiation. When the balance is perturbed, a temperature change and hence a climate change of the Earth will occur. One possible perturbation of the balance is the CO2 greenhouse effect: when the amount of CO2 in the atmosphere increases, this will reduce the loss of thermal infrared radiation to cold space. Earth will gain more heat and hence the temperature will rise. Another perturbation of the balance can occur through variation of the amount of energy emitted by the sun. When the sun emits more energy, this will directly cause a rise of temperature on Earth. For a long time scientists believed that the energy emitted by the sun was constant. The 'solar constant' is defined as the amount of solar energy received per unit surface at a distance of one astronomical unit (the average distance of Earth's orbit) from the sun. Accurate measurements of the variations of the solar constant have been made since 1978. From these we know that the solar constant varies approximately with the 11-year solar cycle observed in other solar phenomena, such as the occurrence of sunspots, dark spots that are sometimes visible on the solar surface. When a sunspot occurs on the sun, since the spot is dark, the radiation (light) emitted by the sun drops instantaneously. Oddly, periods of high solar activity, when a lot of sunspot numbers increase, correspond to periods when the average solar constant is high. This indicates that

  2. The Solar Twin Planet Search. V. Close-in, low-mass planet candidates and evidence of planet accretion in the solar twin HIP 68468

    NASA Astrophysics Data System (ADS)

    Meléndez, Jorge; Bedell, Megan; Bean, Jacob L.; Ramírez, Iván; Asplund, Martin; Dreizler, Stefan; Yan, Hong-Liang; Shi, Jian-Rong; Lind, Karin; Ferraz-Mello, Sylvio; Galarza, Jhon Yana; dos Santos, Leonardo; Spina, Lorenzo; Maia, Marcelo Tucci; Alves-Brito, Alan; Monroe, TalaWanda; Casagrande, Luca

    2017-01-01

    Context. More than two thousand exoplanets have been discovered to date. Of these, only a small fraction have been detected around solar twins, which are key stars because we can obtain accurate elemental abundances especially for them, which is crucial for studying the planet-star chemical connection with the highest precision. Aims: We aim to use solar twins to characterise the relationship between planet architecture and stellar chemical composition. Methods: We obtained high-precision (1 m s-1) radial velocities with the HARPS spectrograph on the ESO 3.6 m telescope at La Silla Observatory and determined precise stellar elemental abundances ( 0.01 dex) using spectra obtained with the MIKE spectrograph on the Magellan 6.5 m telescope. Results: Our data indicate the presence of a planet with a minimum mass of 26 ± 4 Earth masses around the solar twin HIP 68468. The planet is more massive than Neptune (17 Earth masses), but unlike the distant Neptune in our solar system (30 AU), HIP 68468c is close-in, with a semi-major axis of 0.66 AU, similar to that of Venus. The data also suggest the presence of a super-Earth with a minimum mass of 2.9 ± 0.8 Earth masses at 0.03 AU; if the planet is confirmed, it will be the fifth least massive radial velocity planet candidate discovery to date and the first super-Earth around a solar twin. Both isochrones (5.9 ± 0.4 Gyr) and the abundance ratio [Y/Mg] (6.4 ± 0.8 Gyr) indicate an age of about 6 billion years. The star is enhanced in refractory elements when compared to the Sun, and the refractory enrichment is even stronger after corrections for Galactic chemical evolution. We determined a nonlocal thermodynamic equilibrium Li abundance of 1.52 ± 0.03 dex, which is four times higher than what would be expected for the age of HIP 68468. The older age is also supported by the low log () (-5.05) and low jitter (<1 m s-1). Engulfment of a rocky planet of 6 Earth masses can explain the enhancement in both lithium and the

  3. Solar system constraints on planetary Coriolis-type effects induced by rotation of distant masses

    SciTech Connect

    Iorio, Lorenzo

    2010-08-01

    We phenomenologically put local constraints on the rotation of distant masses by using the planets of the solar system. First, we analytically compute the orbital secular precessions induced on the motion of a test particle about a massive primary by a Coriolis-like force, treated as a small perturbation, in the case of a constant angular velocity vector Ψ directed along a generic direction in space. The semimajor axis a and the eccentricity e of the test particle do not secularly change, contrary to the inclination I, the longitude of the ascending node Ω, the longitude of the pericenter varpi and the mean anomaly M. Then, we compare our prediction for (dot varpi) with the corrections Δdot varpi to the usual perihelion precessions of the inner planets recently estimated by fitting long data sets with different versions of the EPM ephemerides. We obtain as preliminary upper bounds |Ψ{sub z}| ≤ 0.0006−0.013 arcsec cty{sup −1}, |Ψ{sub x}| ≤ 0.1−2.7 arcsec cty{sup −1}, |Ψ{sub y}| ≤ 0.3−2.3 arcsec cty{sup −1}. Interpreted in terms of models of space-time involving cosmic rotation, our results are able to yield constraints on cosmological parameters like the cosmological constant Λ and the Hubble parameter H{sub 0} not too far from their values determined with cosmological observations and, in some cases, several orders of magnitude better than the constraints usually obtained so far from space-time models not involving rotation. In the case of the rotation of the solar system throughout the Galaxy, occurring clockwise about the North Galactic Pole, our results for Ψ{sub z} are in disagreement with the expected value of it at more than 3−σ level. Modeling the Oort cloud as an Einstein-Thirring slowly rotating massive shell inducing Coriolis-type forces inside yields unphysical results for its putative rotation.

  4. Highly efficient solar cells based on poly(3-butylthiophene) nanowires.

    PubMed

    Xin, Hao; Kim, Felix Sunjoo; Jenekhe, Samson A

    2008-04-23

    Poly(3-butylthiophene) (P3BT) nanowires, prepared by solution-phase self-assembly, have been used to construct highly efficient P3BT/fullerene nanocomposite solar cells. The fullerene/P3BT nanocomposite films showed an electrically bicontinuous nanoscale morphology with average field-effect hole mobilities as high as 8.0 x 10(-3) cm2/Vs due to the interconnected P3BT nanowire network revealed by TEM and AFM imaging. The power conversion efficiency of fullerene/P3BT nanowire devices was 3.0% (at 100 mW/cm2, AM1.5) in air and found to be identical with our similarly tested fullerene/poly(3-hexylthiophene) photovoltaic cells. This discovery expands the scope of promising materials and architectures for efficient bulk heterojunction solar cells.

  5. Concentrating Solar Power Gen3 Demonstration Roadmap

    SciTech Connect

    Mehos, Mark; Turchi, Craig; Vidal, Judith; Wagner, Michael; Ma, Zhiwen; Ho, Clifford; Kolb, William; Andraka, Charles; Kruizenga, Alan

    2017-01-01

    Today's power-tower concentrating solar power (CSP) technology exists in large part as a result of Department of Energy (DOE) and utility industry funding of demonstration systems in the 1980s and 1990s. Today's most advanced towers are integrated with molten-salt thermal energy storage, delivering thermal energy at 565 degrees C for integration with conventional steam-Rankine cycles. The supercritical carbon dioxide power cycle has been identified as a likely successor to the steam-Rankine power cycle due to its potential for high efficiency when operating at elevated temperatures of 700 degrees C or greater. Over the course of the SunShot Initiative, DOE has supported a number of technology pathways that can operate efficiently at these temperatures and that hold promise to be reliable and cost effective. Three pathways - molten salt, particle, and gaseous - were selected for further investigation based on a two-day workshop held in August of 2016. The information contained in this roadmap identifies research and development challenges and lays out recommended research activities for each of the three pathways. DOE foresees that by successfully addressing the challenges identified in this roadmap, one or more technology pathways will be positioned for demonstration and subsequent commercialization within the next ten years. Based on current knowledge of the three power tower technologies, all three have the potential to achieve the SunShot goal of 6 cents/kilowatt-hour. Further development, modeling, and testing are now required to bring one or more of the technologies to a stage where integrated system tests and pilot demonstrations are feasible.

  6. A 17-billion-solar-mass black hole in a group galaxy with a diffuse core.

    PubMed

    Thomas, Jens; Ma, Chung-Pei; McConnell, Nicholas J; Greene, Jenny E; Blakeslee, John P; Janish, Ryan

    2016-04-21

    Quasars are associated with and powered by the accretion of material onto massive black holes; the detection of highly luminous quasars with redshifts greater than z = 6 suggests that black holes of up to ten billion solar masses already existed 13 billion years ago. Two possible present-day 'dormant' descendants of this population of 'active' black holes have been found in the galaxies NGC 3842 and NGC 4889 at the centres of the Leo and Coma galaxy clusters, which together form the central region of the Great Wall--the largest local structure of galaxies. The most luminous quasars, however, are not confined to such high-density regions of the early Universe; yet dormant black holes of this high mass have not yet been found outside of modern-day rich clusters. Here we report observations of the stellar velocity distribution in the galaxy NGC 1600--a relatively isolated elliptical galaxy near the centre of a galaxy group at a distance of 64 megaparsecs from Earth. We use orbit superposition models to determine that the black hole at the centre of NGC 1600 has a mass of 17 billion solar masses. The spatial distribution of stars near the centre of NGC 1600 is rather diffuse. We find that the region of depleted stellar density in the cores of massive elliptical galaxies extends over the same radius as the gravitational sphere of influence of the central black holes, and interpret this as the dynamical imprint of the black holes.

  7. 3D-printed external light trap for solar cells.

    PubMed

    van Dijk, Lourens; Paetzold, Ulrich W; Blab, Gerhard A; Schropp, Ruud E I; di Vece, Marcel

    2016-05-01

    We present a universally applicable 3D-printed external light trap for enhanced absorption in solar cells. The macroscopic external light trap is placed at the sun-facing surface of the solar cell and retro-reflects the light that would otherwise escape. The light trap consists of a reflective parabolic concentrator placed on top of a reflective cage. Upon placement of the light trap, an improvement of 15% of both the photocurrent and the power conversion efficiency in a thin-film nanocrystalline silicon (nc-Si:H) solar cell is measured. The trapped light traverses the solar cell several times within the reflective cage thereby increasing the total absorption in the cell. Consequently, the trap reduces optical losses and enhances the absorption over the entire spectrum. The components of the light trap are 3D printed and made of smoothened, silver-coated thermoplastic. In contrast to conventional light trapping methods, external light trapping leaves the material quality and the electrical properties of the solar cell unaffected. To explain the theoretical operation of the external light trap, we introduce a model that predicts the absorption enhancement in the solar cell by the external light trap. The corresponding calculated path length enhancement shows good agreement with the empirically derived value from the opto-electrical data of the solar cell. Moreover, we analyze the influence of the angle of incidence on the parasitic absorptance to obtain full understanding of the trap performance. © 2015 The Authors. Progress in Photovoltaics: Research and Applications published by John Wiley & Sons, Ltd.

  8. Silicon solar cells with Al2O3 antireflection coating

    NASA Astrophysics Data System (ADS)

    Dobrzański, Leszek; Szindler, Marek; Drygała, Aleksandra; Szindler, Magdalena

    2014-09-01

    The paper presents the possibility of using Al2O3 antireflection coatings deposited by atomic layer deposition ALD. The ALD method is based on alternate pulsing of the precursor gases and vapors onto the substrate surface and then chemisorption or surface reaction of the precursors. The reactor is purged with an inert gas between the precursor pulses. The Al2O3 thin film in structure of the finished solar cells can play the role of both antireflection and passivation layer which will simplify the process. For this research 50×50 mm monocrystalline silicon solar cells with one bus bar have been used. The metallic contacts were prepared by screen printing method and Al2O3 antireflection coating by ALD method. Results and their analysis allow to conclude that the Al2O3 antireflection coating deposited by ALD has a significant impact on the optoelectronic properties of the silicon solar cell. For about 80 nm of Al2O3 the best results were obtained in the wavelength range of 400 to 800 nm reducing the reflection to less than 1%. The difference in the solar cells efficiency between with and without antireflection coating was 5.28%. The LBIC scan measurements may indicate a positive influence of the thin film Al2O3 on the bulk passivation of the silicon.

  9. In2O3 based perovskite solar cells

    NASA Astrophysics Data System (ADS)

    Dong, Qi; Liu, Fangzhou; Wong, Man Kwong; Djurišić, Aleksandra B.; Ren, Zhiwei; Shen, Qian; Ng, Annie; Surya, Charles; Chan, Wai Kin

    2016-02-01

    Hybrid organic-inorganic perovskite solar cells have attracted lots of attention in recent years. Growth and properties of perovskite layer and its relationship to photovoltaic performance have been extensively studied. Comparably less attention was devoted to the research of the influence of electron transporting layer (ETL). Conventionally, TiO2 is selected as ETL. However, photocatalytic property of this transparent conductive metal oxide reduces the stability of perovskite solar cells under illumination. To realize the commercialization, the stability of perovskite solar cell must be improved. In this study, we replace TiO2 by In2O3, which is not only transparent and conductive, but also has little photocatalytic effect and it has higher electron mobility than TiO2. Investigation on different solution process methods of In2O3 as ETL is demonstrated.

  10. Association of 3He-Rich Solar Energetic Particles with Large-scale Coronal Waves

    NASA Astrophysics Data System (ADS)

    Bučík, Radoslav; Innes, Davina E.; Mason, Glenn M.; Wiedenbeck, Mark E.

    2016-12-01

    Small, 3He-rich solar energetic particle (SEP) events have been commonly associated with extreme-ultraviolet (EUV) jets and narrow coronal mass ejections (CMEs) that are believed to be the signatures of magnetic reconnection, involving field lines open to interplanetary space. The elemental and isotopic fractionation in these events are thought to be caused by processes confined to the flare sites. In this study, we identify 32 3He-rich SEP events observed by the Advanced Composition Explorer, near the Earth, during the solar minimum period 2007-2010, and we examine their solar sources with the high resolution Solar Terrestrial Relations Observatory (STEREO) EUV images. Leading the Earth, STEREO-A has provided, for the first time, a direct view on 3He-rich flares, which are generally located on the Sun’s western hemisphere. Surprisingly, we find that about half of the 3He-rich SEP events in this survey are associated with large-scale EUV coronal waves. An examination of the wave front propagation, the source-flare distribution, and the coronal magnetic field connections suggests that the EUV waves may affect the injection of 3He-rich SEPs into interplanetary space.

  11. History and development of coronal mass ejections as a key player in solar terrestrial relationship

    NASA Astrophysics Data System (ADS)

    Gopalswamy, N.

    2016-12-01

    Coronal mass ejections (CMEs) are relatively a recently discovered phenomenon—in 1971, some 15 years into the Space Era. It took another two decades to realize that CMEs are the most important players in solar terrestrial relationship as the root cause of severe weather in Earth's space environment. CMEs are now counted among the major natural hazards because they cause large solar energetic particle (SEP) events and major geomagnetic storms, both of which pose danger to humans and their technology in space and ground. Geomagnetic storms discovered in the 1700s, solar flares discovered in the 1800s, and SEP events discovered in the 1900s are all now found to be closely related to CMEs via various physical processes occurring at various locations in and around CMEs, when they interact with the ambient medium. This article identifies a number of key developments that preceded the discovery of white-light CMEs suggesting that CMEs were waiting to be discovered. The last two decades witnessed an explosion of CME research following the launch of the Solar and Heliospheric Observatory mission in 1995, resulting in the establishment of a full picture of CMEs.

  12. Solar signatures and eruption mechanism of the August 14, 2010 coronal mass ejection (CME)

    NASA Astrophysics Data System (ADS)

    D'Huys, Elke; Seaton, Daniel B.; De Groof, Anik; Berghmans, David; Poedts, Stefaan

    2017-03-01

    On August 14, 2010 a wide-angled coronal mass ejection (CME) was observed. This solar eruption originated from a destabilized filament that connected two active regions and the unwinding of this filament gave the eruption an untwisting motion that drew the attention of many observers. In addition to the erupting filament and the associated CME, several other low-coronal signatures that typically indicate the occurrence of a solar eruption were associated with this event. However, contrary to what was expected, the fast CME (v > 900 km s-1) was accompanied by only a weak C4.4 flare. We investigate the various eruption signatures that were observed for this event and focus on the kinematic evolution of the filament in order to determine its eruption mechanism. Had this solar eruption occurred just a few days earlier, it could have been a significant event for space weather. The risk of underestimating the strength of this eruption based solely on the C4.4 flare illustrates the need to include all eruption signatures in event analyses in order to obtain a complete picture of a solar eruption and assess its possible space weather impact.

  13. OBSERVATIONS OF EUV WAVES IN {sup 3}He-RICH SOLAR ENERGETIC PARTICLE EVENTS

    SciTech Connect

    Bucík, R.; Innes, D. E.; Guo, L.; Mason, G. M.; Wiedenbeck, M. E.

    2015-10-10

    Small {sup 3}He-rich solar energetic particle (SEP) events with their anomalous abundances, markedly different from the solar system, provide evidence for a unique acceleration mechanism that operates routinely near solar active regions. Although the events are sometimes accompanied by coronal mass ejections (CMEs), it is believed that mass and isotopic fractionation is produced directly in the flare sites on the Sun. We report on a large-scale extreme-ultraviolet (EUV) coronal wave observed in association with {sup 3}He-rich SEP events. In the two examples discussed, the observed waves were triggered by minor flares and appeared concurrently with EUV jets and type III radio bursts, but without CMEs. The energy spectra from one event are consistent with so-called class-1 (characterized by power laws) {sup 3}He-rich SEP events, while the other with class-2 (characterized by rounded {sup 3}He and Fe spectra), suggesting different acceleration mechanisms in the two. The observation of EUV waves suggests that large-scale disturbances, in addition to more commonly associated jets, may be responsible for the production of {sup 3}He-rich SEP events.

  14. KINEMATIC TREATMENT OF CORONAL MASS EJECTION EVOLUTION IN THE SOLAR WIND

    NASA Technical Reports Server (NTRS)

    Riley, Pete; Crooker, N. U.

    2004-01-01

    We present a kinematic study of the evolution of coronal mass ejections (CMEs) in the solar wind. Specifically, we consider the effects of (1) spherical expansion and (2) uniform expansion due to pressure gradients between the interplanetary CME (ICME) and the ambient solar wind. We compare these results with an MHD model that allows us to isolate these effects h m the combined kinematic and dynamical effects, which are included in MHD models. They also provide compelling evidence that the fundamental cross section of so-called "force-free" flux ropes (or magnetic clouds) is neither circular or elliptical, but rather a convex-outward, "pancake" shape. We apply a force-free fit to the magnetic vectors from the MHD simulation to assess how the distortion of the flux rope affects the fit. In spite of these limitations, force-free fits, which are straightforward to apply, do provide an important description of a number of parameters, including the radial dimension, orientation, and chirality of the ICME. Subject headings: MHD - solar wind - Sun: activity - Sun: corona - Sun: coronal mass ejections (CMEs) - On-line material color figures Sun: magnetic fields

  15. Embedded Protostellar Disks Around (Sub-)Solar Stars. II. Disk Masses, Sizes, Densities, Temperatures, and the Planet Formation Perspective

    NASA Astrophysics Data System (ADS)

    Vorobyov, Eduard I.

    2011-03-01

    We present basic properties of protostellar disks in the embedded phase of star formation (EPSF), which is difficult to probe observationally using available observational facilities. We use numerical hydrodynamics simulations of cloud core collapse and focus on disks formed around stars in the 0.03-1.0 M sun mass range. Our obtained disk masses scale near-linearly with the stellar mass. The mean and median disk masses in the Class 0 and I phases (M mean d,C0 = 0.12 M sun, M mdn d,C0 = 0.09 M sun and M mean d,CI = 0.18 M sun, M mdn d,CI = 0.15 M sun, respectively) are greater than those inferred from observations by (at least) a factor of 2-3. We demonstrate that this disagreement may (in part) be caused by the optically thick inner regions of protostellar disks, which do not contribute to millimeter dust flux. We find that disk masses and surface densities start to systematically exceed that of the minimum mass solar nebular for objects with stellar mass as low as M * = 0.05-0.1 M sun. Concurrently, disk radii start to grow beyond 100 AU, making gravitational fragmentation in the disk outer regions possible. Large disk masses, surface densities, and sizes suggest that giant planets may start forming as early as in the EPSF, either by means of core accretion (inner disk regions) or direct gravitational instability (outer disk regions), thus breaking a longstanding stereotype that the planet formation process begins in the Class II phase.

  16. Are the Faint Structures Ahead of Solar Coronal Mass Ejections Real Signatures of Driven Shocks?

    NASA Astrophysics Data System (ADS)

    Lee, Jae-Ok; Moon, Y.-J.; Lee, Jin-Yi; Lee, Kyoung-Sun; Kim, Sujin; Lee, Kangjin

    2014-11-01

    Recently, several studies have assumed that the faint structures ahead of coronal mass ejections (CMEs) are caused by CME-driven shocks. In this study, we have conducted a statistical investigation to determine whether or not the appearance of such faint structures depends on CME speeds. For this purpose, we use 127 Solar and Heliospheric Observatory/Large Angle Spectroscopic COronagraph (LASCO) front-side halo (partial and full) CMEs near the limb from 1997 to 2011. We classify these CMEs into two groups by visual inspection of CMEs in the LASCO-C2 field of view: Group 1 has the faint structure ahead of a CME and Group 2 does not have such a structure. We find the following results. (1) Eighty-seven CMEs belong to Group 1 and 40 CMEs belong to Group 2. (2) Group 1 events have much higher speeds (average = 1230 km s-1 and median = 1199 km s-1) than Group 2 events (average = 598 km s-1 and median = 518 km s-1). (3) The fraction of CMEs with faint structures strongly depends on CME speeds (V): 0.93 (50/54) for fast CMEs with V >= 1000 km s-1, 0.65 (34/52) for intermediate CMEs with 500 km s-1 <= V < 1000 km s-1, and 0.14 (3/21) for slow CMEs with V < 500 km s-1. We also find that the fraction of CMEs with deca-hecto metric type II radio bursts is consistent with the above tendency. Our results indicate that the observed faint structures ahead of fast CMEs are most likely an enhanced density manifestation of CME-driven shocks.

  17. ARE THE FAINT STRUCTURES AHEAD OF SOLAR CORONAL MASS EJECTIONS REAL SIGNATURES OF DRIVEN SHOCKS?

    SciTech Connect

    Lee, Jae-Ok; Moon, Y.-J.; Lee, Kangjin; Lee, Jin-Yi; Lee, Kyoung-Sun; Kim, Sujin E-mail: moonyj@khu.ac.kr

    2014-11-20

    Recently, several studies have assumed that the faint structures ahead of coronal mass ejections (CMEs) are caused by CME-driven shocks. In this study, we have conducted a statistical investigation to determine whether or not the appearance of such faint structures depends on CME speeds. For this purpose, we use 127 Solar and Heliospheric Observatory/Large Angle Spectroscopic COronagraph (LASCO) front-side halo (partial and full) CMEs near the limb from 1997 to 2011. We classify these CMEs into two groups by visual inspection of CMEs in the LASCO-C2 field of view: Group 1 has the faint structure ahead of a CME and Group 2 does not have such a structure. We find the following results. (1) Eighty-seven CMEs belong to Group 1 and 40 CMEs belong to Group 2. (2) Group 1 events have much higher speeds (average = 1230 km s{sup –1} and median = 1199 km s{sup –1}) than Group 2 events (average = 598 km s{sup –1} and median = 518 km s{sup –1}). (3) The fraction of CMEs with faint structures strongly depends on CME speeds (V): 0.93 (50/54) for fast CMEs with V ≥ 1000 km s{sup –1}, 0.65 (34/52) for intermediate CMEs with 500 km s{sup –1} ≤ V < 1000 km s{sup –1}, and 0.14 (3/21) for slow CMEs with V < 500 km s{sup –1}. We also find that the fraction of CMEs with deca-hecto metric type II radio bursts is consistent with the above tendency. Our results indicate that the observed faint structures ahead of fast CMEs are most likely an enhanced density manifestation of CME-driven shocks.

  18. MAST - A mass spectrometer telescope for studies of the isotopic composition of solar, anomalous, and galactic cosmic ray nuclei

    NASA Technical Reports Server (NTRS)

    Cook, Walter R.; Cummings, Alan C.; Cummings, Jay R.; Garrard, Thomas L.; Kecman, Branislav; Mewaldt, Richard A.; Selesnick, Richard S.; Stone, Edward C.; Von Rosenvinge, T. T.

    1993-01-01

    The Mass Spectrometer Telescope (MAST) on SAMPEX is designed to provide high resolution measurements of the isotopic composition of energetic nuclei from He to Ni (Z = 2 to 28) over the energy range from about 10 to several hundred MeV/nuc. During large solar flares MAST will measure the isotopic abundances of solar energetic particles to determine directly the composition of the solar corona, while during solar quiet times MAST will study the isotopic composition of galactic cosmic rays. In addition, MAST will measure the isotopic composition of both interplanetary and trapped fluxes of anomalous cosmic rays, believed to be a sample of the nearby interstellar medium.

  19. Onset of the Magnetic Explosion in Solar Flames and Coronal Mass Ejections

    NASA Technical Reports Server (NTRS)

    Moore, Ronald L.; Sterling, Alphonse C.; Hudson, Hugh S.; Lemen, James R.

    2001-01-01

    We present observations of the magnetic field configuration and its transformation in six solar eruptive events that show good agreement with the standard bipolar model for eruptive flares. The observations are X-ray images from the Yohkoh soft X-ray telescope (SXT) and magnetograms from Kitt Peak National Solar Observatory, interpreted together with the 1-8 Angstrom X-ray flux observed by Geostationary Operational Environmental Satellites (GOES). The observations yield the following interpretations: (1) Each event is a magnetic explosion that occurs in an initially closed single bipole in which the core field is sheared and twisted in the shape of a sigmoid, having an oppositely curved elbow on each end. The arms of the opposite elbows are sheared past each other so that they overlap and are crossed low above the neutral line in the middle of the bipole. The elbows and arms seen in the SXT images are illuminated strands of the sigmoidal core field, which is a continuum of sheared/twisted field that fills these strands as well as the space between and around them; (2) Although four of the explosions are ejective (appearing to blow open the bipole) and two are confined (appearing to be arrested within the closed bipole), all six begin the same way. In the SXT images, the explosion begins with brightening and expansion of the two elbows together with the appearance of short bright sheared loops low over the neutral line under the crossed arms and, rising up from the crossed arms, long strands connecting the far ends of the elbows; and (3) All six events are single-bipole events in that during the onset and early development of the explosion they show no evidence for reconnection between the exploding bipole and any surrounding magnetic fields. We conclude that in each of our events the magnetic explosion was unleashed by runaway tether-cutting via implosive/explosive reconnection in the middle of the sigmoid, as in the standard model. The similarity of the onsets of

  20. Imaging solar coronal magnetic structures in 3D

    NASA Astrophysics Data System (ADS)

    Cartledge, N. P.

    The study of solar coronal structures and, in particular prominences, is a key part of understanding the highly complex physical mechanisms occurring in the Sun's atmosphere. Solar prominences are important in their own right and some of the most puzzling questions in solar theory have arisen through their study. For example, how do they form and how is their mass continuously replenished? How can the magnetic field provide their continuous support against gravity over time periods of several months? How can such cool, dense material exist in thermal equilibrium in the surrounding coronal environment? Why do they erupt? A study of their structure and that of the surrounding medium is important in determining the nature of the coronal plasma and magnetic field. Also, prominences are closely associated with other key phenomena such as coronal mass ejections and eruptive solar flares which occur as a prominence loses equilibrium and rises from the solar surface. Our current understanding of these fascinating structures is extremely limited and we know very little about their basic global structure. In fact, recent prominence observations have caused our basic paradigms to be challenged (Priest, 1996) and so we must set up new models in order to gain even a fundamental understanding. Prominences are highly nonlinear, three-dimensional structures. Large feet (or barbs) reach out from the main body of a prominence and reach down to the photosphere where the dense material continuously drains away. These provide a real clue to the three-dimensional nature of the coronal field and its relation to the photospheric field. It is important, therefore, to make stereographic observations of prominences in order to gain a basic understanding of their essentially three-dimensional nature and attempt to formulate new paradigms for their structure and evolution. There is no doubt that the study of prominences in three dimensions is a crucial exercise if we are to develop a better

  1. Asteroid Masses V3.0

    NASA Astrophysics Data System (ADS)

    Baer, J.; Chesley, S.; Britt, D.

    2012-06-01

    This collection of asteroid masses and densities was compiled from the published literature by Jim Baer, Steve Chesley, and Dan Britt. Size and shape information are included as well to show the source of the tabulated bulk density. This is the version of the compilation as of April 18, 2012.

  2. Impact of thermal energy storage properties on solar dynamic space power conversion system mass

    NASA Technical Reports Server (NTRS)

    Juhasz, Albert J.; Coles-Hamilton, Carolyn E.; Lacy, Dovie E.

    1987-01-01

    A 16 parameter solar concentrator/heat receiver mass model is used in conjunction with Stirling and Brayton Power Conversion System (PCS) performance and mass computer codes to determine the effect of thermal energy storage (TES) material property changes on overall PCS mass as a function of steady state electrical power output. Included in the PCS mass model are component masses as a function of thermal power for: concentrator, heat receiver, heat exchangers (source unless integral with heat receiver, heat sink, regenerator), heat engine units with optional parallel redundancy, power conditioning and control (PC and C), PC and C radiator, main radiator, and structure. Critical TES properties are: melting temperature, heat of fusion, density of the liquid phase, and the ratio of solid-to-liquid density. Preliminary results indicate that even though overall system efficiency increases with TES melting temperature up to 1400 K for concentrator surface accuracies of 1 mrad or better, reductions in the overall system mass beyond that achievable with lithium fluoride (LiF) can be accomplished only if the heat of fusion is at least 800 kJ/kg and the liquid density is comparable to that of LiF (1800 kg/cu m).

  3. Impact of thermal energy storage properties on solar dynamic space power conversion system mass

    NASA Technical Reports Server (NTRS)

    Juhasz, Albert J.; Coles-Hamilton, Carolyn E.; Lacy, Dovie E.

    1987-01-01

    A 16 parameter solar concentrator/heat receiver mass model is used in conjunction with Stirling and Brayton Power Conversion System (PCS) performance and mass computer codes to determine the effect of thermal energy storage (TES) material property changes on overall PCS mass as a function of steady state electrical power output. Included in the PCS mass model are component masses as a function of thermal power for: concentrator, heat receiver, heat exchangers (source unless integral with heat receiver, heat sink, regenerator), heat engine units with optional parallel redundancy, power conditioning and control (PC and C), PC and C radiator, main radiator, and structure. Critical TES properties are: melting temperature, heat of fusion, density of the liquid phase, and the ratio of solid-to-liquid density. Preliminary results indicate that even though overalll system efficiency increases with TES melting temperature up to 1400 K for concentrator surface accuracies of 1 mrad or better, reductions in the overall system mass beyond that achievable with lithium fluoride (LiF) can be accomplished only if the heat of fusion is at least 800 kJ/kg and the liquid density is comparable to that of LiF (1880 kg/cu m.

  4. Initiation of coronal mass ejection event observed on 2010 November 3: multi-wavelength perspective

    SciTech Connect

    Mulay, Sargam; Subramanian, Srividya; Tripathi, Durgesh; Isobe, Hiroaki; Glesener, Lindsay

    2014-10-10

    One of the major unsolved problems in solar physics is that of coronal mass ejection (CME) initiation. In this paper, we have studied the initiation of a flare-associated CME that occurred on 2010 November 3 using multi-wavelength observations recorded by the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory and the Reuven Ramaty High Energy Solar Spectroscopic Imager. We report an observation of an inflow structure initially in the 304 Å and the 1600 Å images a few seconds later. This inflow structure was detected as one of the legs of the CME. We also observed a non-thermal compact source concurrent and near co-spatial with the brightening and movement of the inflow structure. The appearance of this compact non-thermal source, brightening, and movement of the inflow structure and the subsequent outward movement of the CME structure in the corona led us to conclude that the CME initiation was caused by magnetic reconnection.

  5. On the Rates of Coronal Mass Ejections: Remote Solar and In Situ Observations

    NASA Technical Reports Server (NTRS)

    Riley, Pete; Schatzman, C.; Cane, H. V.; Richardson, I. G.; Gopalswamy, N.

    2006-01-01

    We compare the rates of coronal mass ejections (CMEs) as inferred from remote solar observations and interplanetary CMEs (ICMEs) as inferred from in situ observations at both 1 AU and Ulyssses from 1996 through 2004. We also distinguish between those ICMEs that contain a magnetic cloud (MC) and those that do not. While the rates of CMEs and ICMEs track each other well at solar minimum, they diverge significantly in early 1998, during the ascending phase of the solar cycle, with the remote solar observations yielding approximately 20 times more events than are seen at 1 AU. This divergence persists through 2004. A similar divergence occurs between MCs and non-MC ICMEs. We argue that these divergences are due to the birth of midlatitude active regions, which are the sites of a distinct population of CMEs, only partially intercepted by Earth, and we present a simple geometric argument showing that the CME and ICME rates are consistent with one another. We also acknowledge contributions from (1) an increased rate of high-latitude CMEs and (2) focusing effects from the global solar field. While our analysis, coupled with numerical modeling results, generally supports the interpretation that whether one observes a MC within an ICME is sensitive to the trajectory of the spacecraft through the ICME (i.e., an observational selection effect), one result directly contradicts it. Specifically, we find no systematic offset between the latitudinal origin of ICMEs that contain MCs at 1 AU in the ecliptic plane and that of those that do not.

  6. Compressive Acceleration of Solar Energetic Particles within Coronal Mass Ejections: Observations and Theory Relevant to the Solar Probe Plus and Solar Orbiter Missions

    NASA Astrophysics Data System (ADS)

    Roelof, E. C.

    2015-12-01

    Observations of solar energetic particles (SEPs) over Solar Cycles 22-24 included the measurement of their pitch-angle distributions (PADs). When only magnetically "well-connected" SEP events were selected, i.e., with the spacecraft on interplanetary magnetic field (IMF) lines whose coronal foot-points were within about 30 deg of the associated flare site, the PADs were usually "beam-like" during the rise-to-maximum phase (RTM) of the events. This nearly "scatter-free" propagation (due to magnetic focusing of the IMF) revealed that the injection times of the SEPs were delayed up to 10s of minutes after the onset of electromagnetic emissions from the flare. Direct comparison with the flare-associated coronal mass ejections (CMEs) from the western hemisphere indicated that the SEP acceleration/injection was occurring at least 1 Rs into the corona (and often continuing well above that radial distance). Moreover, the RTM profiles exhibited a continuum of shapes, from "spikes" to "pulses" to "ramps", and these shape characterizations ordered the properties of the associated CMEs. Most importantly, when compared at nearly the same near-relativistic velocities, electrons and protons exhibited similar PADs and RTM profiles. Clearly, such orderly patterns in the data call for a single dominant acceleration process that treats all particles of similar velocities the same, regardless of mass and charge. A simple theory that meets all of these requirements, based on nearly scatter-free propagation and energy change within particle "reservoirs" (such as the closed magnetic structure of a CME), has recently been proposed [Roelof, Proc. 14th Ann. Int'l. Astrophys. Conf., IOP, in press, 2015]. The acceleration results from compression (-divV) of the driver plasma, well sunward of the CME shock. Acceleration (e-folding) times of only a few minutes can be obtained from representative parameters of 1000 km/s CMEs. A companion paper [Roelof and Vourlidas, op. cit.], proposed a new

  7. Total solar eclipse of 3 November 1994

    NASA Technical Reports Server (NTRS)

    Espenak, Fred; Anderson, Jay

    1993-01-01

    A total eclipse of the Sun will be visible from the southern half of the Western Hemisphere on 3 November 1994. The path of the Moon's shadow passes through Peru, Chile, Bolivia, Paraguay, and Brazil. Detailed predictions for this event are presented and include tables of geographic coordinates of the path of totality, local circumstances for hundreds of cities, maps of the path of total and partial eclipse, weather prospects, and the lunar limb profile.

  8. Air mass 1.5 global and direct solar simulation and secondary reference cell calibration using a filtered large area pulsed solar simulator

    NASA Technical Reports Server (NTRS)

    Mueller, Robert L.

    1985-01-01

    Spectral mismatch between a solar simulator and a desired spectrum can result in nearly 20 percent measurement error in the output of photovoltaic devices. This occurs when a crystalline silicon cell monitors the intensity of an unfiltered large area pulsed solar simulator (LAPSS) simulating the ASTM air mass 1.5 direct spectrum and the test device is amorphous silicon. The LAPSS spectral irradiance is modified with readily available glass UV filters to closely match either the ASTM air mass 1.5 direct or global spectrum. Measurement error is reduced to about 1 percent when using either filter if the reference cell and test device are the same general type.

  9. 3D Imaging by Mass Spectrometry: A New Frontier

    PubMed Central

    Seeley, Erin H.; Caprioli, Richard M.

    2012-01-01

    Summary Imaging mass spectrometry can generate three-dimensional volumes showing molecular distributions in an entire organ or animal through registration and stacking of serial tissue sections. Here we review the current state of 3D imaging mass spectrometry as well as provide insights and perspectives on the process of generating 3D mass spectral data along with a discussion of the process necessary to generate a 3D image volume. PMID:22276611

  10. THE EVOLUTION OF THE SOLAR NEBULA I. EVOLUTION OF THE GLOBAL PROPERTIES AND PLANET MASSES

    SciTech Connect

    Jin Liping; Sui Ning E-mail: suining@email.jlu.edu.c

    2010-02-20

    We investigate the formation, structure, and evolution of the solar nebula by including nonuniform viscosity and the mass influx from the gravitational collapse of the molecular cloud core. The calculations are done by using currently accepted viscosity, which is nonuniform, and probable mass influx from star formation theory. In the calculation of the viscosity, we include the effect of magnetorotational instability. The radial distributions of the surface density and other physical quantities of the nebula are significantly different from nebula models with constant alpha viscosity and the models which do not include the mass influx. We find that the nebula starts to form from the inner boundary because of the inside-out collapse and then expands due to viscosity. The surface density is not a monotonic function of the radius like the case of uniform viscosity. There are minimums near 1.5 AU due to nonuniform viscosity. The general shape of the surface density is sustained before the mass influx stops because the mass supply offsets mass loss accreted onto the protosun and provides the mass needed for the nebula expansion. We show that not all protoplanetary disks experience gravitational instability during some periods of their lifetime. We find that the nebula becomes gravitationally unstable in some durations when the angular momentum of the cloud core is high. Our numerical calculations confirm Jin's early suggestion that nonuniform viscosity explains the differences in mass and gas content among Jovian planets. Our calculations of nebular evolution show that the nebula temperature is less than 1200 K. Even in the inner portion of the nebula, refractory material from the molecular cloud may survive and refractory condensates may form.

  11. Radio emission and mass loss rate limits of four young solar-type stars

    NASA Astrophysics Data System (ADS)

    Fichtinger, Bibiana; Güdel, Manuel; Mutel, Robert L.; Hallinan, Gregg; Gaidos, Eric; Skinner, Stephen L.; Lynch, Christene; Gayley, Kenneth G.

    2017-03-01

    Aims: Observations of free-free continuum radio emission of four young main-sequence solar-type stars (EK Dra, π1 UMa, χ1 Ori, and κ1 Cet) are studied to detect stellar winds or at least to place upper limits on their thermal radio emission, which is dominated by the ionized wind. The stars in our sample are members of The Sun in Time programme and cover ages of 0.1-0.65 Gyr on the main-sequence. They are similar in magnetic activity to the Sun and thus are excellent proxies for representing the young Sun. Upper limits on mass loss rates for this sample of stars are calculated using their observational radio emission. Our aim is to re-examine the faint young Sun paradox by assuming that the young Sun was more massive in its past, and hence to find a possible solution for this famous problem. Methods: The observations of our sample are performed with the Karl G. Jansky Very Large Array (VLA) with excellent sensitivity, using the C-band receiver from 4-8 GHz and the Ku-band from 12-18 GHz. Atacama Large Millimeter/Submillitmeter Array (ALMA) observations are performed at 100 GHz. The Common Astronomy Software Application (CASA) package is used for the data preparation, reduction, calibration, and imaging. For the estimation of the mass loss limits, spherically symmetric winds and stationary, anisotropic, ionized winds are assumed. We compare our results to 1) mass loss rate estimates of theoretical rotational evolution models; and 2) to results of the indirect technique of determining mass loss rates: Lyman-α absorption. Results: We are able to derive the most stringent direct upper limits on mass loss so far from radio observations. Two objects, EK Dra and χ1 Ori, are detected at 6 and 14 GHz down to an excellent noise level. These stars are very active and additional radio emission identified as non-thermal emission was detected, but limits for the mass loss rates of these objects are still derived. The emission of χ1 Ori does not come from the main target

  12. Modeling heat and mass transport phenomena at higher temperatures in solar distillation systems - The Chilton-Colburn analogy

    SciTech Connect

    Tsilingiris, P.T.

    2010-02-15

    In the present investigation efforts have been devoted towards developing an analysis suitable for heat and mass transfer processes modeling in solar distillation systems, when they are operating at higher temperatures. For this purpose the use of Lewis relation is not new although its validity is based on the assumptions of identical boundary layer concentration and temperature distributions, as well as low mass flux conditions, which are not usually met in solar distillation systems operating at higher temperatures associated with considerable mass transfer rates. The present analysis, taking into consideration these conditions and the temperature dependence of all pertinent thermophysical properties of the saturated binary mixture of water vapor and dry air, leads to the development of an improved predictive accuracy model. This model, having undergone successful first order validation against earlier reported measurements from the literature, appears to offer more accurate predictions of the transport processes and mass flow rate yield of solar stills when operated at elevated temperatures. (author)

  13. The efficiency limit of CH3NH3PbI3 perovskite solar cells

    NASA Astrophysics Data System (ADS)

    Sha, Wei E. I.; Ren, Xingang; Chen, Luzhou; Choy, Wallace C. H.

    2015-06-01

    With the consideration of photon recycling effect, the efficiency limit of methylammonium lead iodide (CH3NH3PbI3) perovskite solar cells is predicted by a detailed balance model. To obtain convincing predictions, both AM 1.5 spectrum of Sun and experimentally measured complex refractive index of perovskite material are employed in the detailed balance model. The roles of light trapping and angular restriction in improving the maximal output power of thin-film perovskite solar cells are also clarified. The efficiency limit of perovskite cells (without the angular restriction) is about 31%, which approaches to Shockley-Queisser limit (33%) achievable by gallium arsenide (GaAs) cells. Moreover, the Shockley-Queisser limit could be reached with a 200 nm-thick perovskite solar cell, through integrating a wavelength-dependent angular-restriction design with a textured light-trapping structure. Additionally, the influence of the trap-assisted nonradiative recombination on the device efficiency is investigated. The work is fundamentally important to high-performance perovskite photovoltaics.

  14. A CRITICAL EXAMINATION OF THE FUNDAMENTAL ASSUMPTIONS OF SOLAR FLARE AND CORONAL MASS EJECTION MODELS

    SciTech Connect

    Spicer, D. S.; Bingham, R.; Harrison, R.

    2013-05-01

    The fundamental assumptions of conventional solar flare and coronal mass ejection (CME) theory are re-examined. In particular, the common theoretical assumption that magnetic energy that drives flares and CMEs can be stored in situ in the corona with sufficient energy density is found wanting. In addition, the observational constraint that flares and CMEs produce non-thermal electrons with fluxes of order 10{sup 34}-10{sup 36} electrons s{sup -1}, with energies of order 10-20 keV, must also be explained. This constraint when imposed on the ''standard model'' for flares and CMEs is found to miss the mark by many orders of magnitude. We suggest, in conclusion, there are really only two possible ways to explain the requirements of observations and theory: flares and CMEs are caused by mass-loaded prominences or driven directly by emerging magnetized flux.

  15. Deflections of Fast Coronal Mass Ejections and the Properties of Associated Solar Energetic Particle Events

    NASA Technical Reports Server (NTRS)

    Kahler, S. W.; Akiyama, S.; Gopalswamy, N.

    2012-01-01

    The onset times and peak intensities of solar energetic particle (SEP) events at Earth have long been thought to be influenced by the open magnetic fields of coronal holes (CHs). The original idea was that a CH lying between the solar SEP source region and the magnetic footpoint of the 1 AU observer would result in a delay in onset and/or a decrease in the peak intensity of that SEP event. Recently, Gopalswamy et al. showed that CHs near coronal mass ejection (CME) source regions can deflect fast CMEs from their expected trajectories in space, explaining the appearance of driverless shocks at 1 AU from CMEs ejected near solar central meridian (CM). This suggests that SEP events originating in CME-driven shocks may show variations attributable to CH deflections of the CME trajectories. Here, we use a CH magnetic force parameter to examine possible effects of CHs on the timing and intensities of 41 observed gradual E approx 20 MeV SEP events with CME source regions within 20 deg. of CM. We find no systematic CH effects on SEP event intensity profiles. Furthermore, we find no correlation between the CME leading-edge measured position angles and SEP event properties, suggesting that the widths of CME-driven shock sources of the SEPs are much larger than the CMEs. Independently of the SEP event properties, we do find evidence for significant CME deflections by CH fields in these events

  16. Propagation of Solar Energetic Particles During Multiple Coronal Mass Ejection Events

    NASA Astrophysics Data System (ADS)

    Pohjolainen, Silja; Al-Hamadani, Firas; Valtonen, Eino

    2016-02-01

    We study solar energetic particle (SEP) events during multiple solar eruptions. The analysed sequences, on 24 - 26 November 2000, 9 - 13 April 2001, and 22 - 25 August 2005, consisted of halo-type coronal mass ejections (CMEs) that originated from the same active region and were associated with intense flares, EUV waves, and interplanetary (IP) radio type II and type III bursts. The first two solar events in each of these sequences showed SEP enhancements near Earth, but the third in the row did not. We observed that in these latter events the type III radio bursts were stopped at much higher frequencies than in the earlier events, indicating that the bursts did not reach the typical plasma density levels near Earth. To explain the missing third SEP event in each sequence, we suggest that the earlier-launched CMEs and the CME-driven shocks either reduced the seed particle population and thus led to inefficient particle acceleration, or that the earlier-launched CMEs and shocks changed the propagation paths or prevented the propagation of both the electron beams and SEPs, so that they were not detected near Earth even when the shock arrivals were recorded.

  17. DEFLECTIONS OF FAST CORONAL MASS EJECTIONS AND THE PROPERTIES OF ASSOCIATED SOLAR ENERGETIC PARTICLE EVENTS

    SciTech Connect

    Kahler, S. W.; Akiyama, S.; Gopalswamy, N.

    2012-08-01

    The onset times and peak intensities of solar energetic particle (SEP) events at Earth have long been thought to be influenced by the open magnetic fields of coronal holes (CHs). The original idea was that a CH lying between the solar SEP source region and the magnetic footpoint of the 1 AU observer would result in a delay in onset and/or a decrease in the peak intensity of that SEP event. Recently, Gopalswamy et al. showed that CHs near coronal mass ejection (CME) source regions can deflect fast CMEs from their expected trajectories in space, explaining the appearance of driverless shocks at 1 AU from CMEs ejected near solar central meridian (CM). This suggests that SEP events originating in CME-driven shocks may show variations attributable to CH deflections of the CME trajectories. Here, we use a CH magnetic force parameter to examine possible effects of CHs on the timing and intensities of 41 observed gradual E {approx} 20 MeV SEP events with CME source regions within 20 Degree-Sign of CM. We find no systematic CH effects on SEP event intensity profiles. Furthermore, we find no correlation between the CME leading-edge measured position angles and SEP event properties, suggesting that the widths of CME-driven shock sources of the SEPs are much larger than the CMEs. Independently of the SEP event properties, we do find evidence for significant CME deflections by CH fields in these events.

  18. Investigation of the Large Scale Evolution and Topology of Coronal Mass Ejections in the Solar Wind

    NASA Technical Reports Server (NTRS)

    Riley, Pete

    2001-01-01

    This investigation is concerned with the large-scale evolution and topology of coronal mass ejections (CMEs) in the solar wind. During the course of this three-year investigation, we have undertaken a number of studies that are discussed in more detail in this report. For example, we conducted an analysis of all CMEs observed by the Ulysses spacecraft during its in-ecliptic phase between 1 and 5 AU. In addition to studying the properties of the ejecta, we also analyzed the shocks that could be unambiguously associated with the fast CMEs. We also analyzed a series of 'density holes' observed in the solar wind that bear many similarities with CMEs. To complement this analysis, we conducted a series of 1-D and 2 1/2-D fluid, MHD, and hybrid simulations to address a number of specific issues related to CME evolution in the solar wind. For example, we used fluid simulations to address the interpretation of negative electron temperature-density relationships often observed within CME/cloud intervals. As part of this investigation, a number of fruitful international collaborations were forged. Finally, the results of this work were presented at nine scientific meetings and communicated in eight scientific, refereed papers.

  19. SOLAR RADIO TYPE-I NOISE STORM MODULATED BY CORONAL MASS EJECTIONS

    SciTech Connect

    Iwai, K.; Tsuchiya, F.; Morioka, A.; Misawa, H.; Miyoshi, Y.; Masuda, S.; Shimojo, M.; Shiota, D.; Inoue, S.

    2012-01-10

    The first coordinated observations of an active region using ground-based radio telescopes and the Solar Terrestrial Relations Observatory (STEREO) satellites from different heliocentric longitudes were performed to study solar radio type-I noise storms. A type-I noise storm was observed between 100 and 300 MHz during a period from 2010 February 6 to 7. During this period the two STEREO satellites were located approximately 65 Degree-Sign (ahead) and -70 Degree-Sign (behind) from the Sun-Earth line, which is well suited to observe the earthward propagating coronal mass ejections (CMEs). The radio flux of the type-I noise storm was enhanced after the preceding CME and began to decrease before the subsequent CME. This time variation of the type-I noise storm was directly related to the change of the particle acceleration processes around its source region. Potential-field source-surface extrapolation from the Solar and Heliospheric Observatory/Michelson Doppler Imager (SOHO/MDI) magnetograms suggested that there was a multipolar magnetic system around the active region from which the CMEs occurred around the magnetic neutral line of the system. From our observational results, we suggest that the type-I noise storm was activated at a side-lobe reconnection region that was formed after eruption of the preceding CME. This magnetic structure was deformed by a loop expansion that led to the subsequent CME, which then suppressed the radio burst emission.

  20. SOLAR JET–CORONAL HOLE COLLISION AND A CLOSELY RELATED CORONAL MASS EJECTION

    SciTech Connect

    Zheng, Ruisheng; Chen, Yao; Du, Guohui; Li, Chuanyang

    2016-03-10

    Jets are defined as impulsive, well-collimated upflows, occurring in different layers of the solar atmosphere with different scales. Their relationship with coronal mass ejections (CMEs), another type of solar impulsive events, remains elusive. Using high-quality imaging data from the Atmospheric Imaging Assembly/Solar Dynamics Observatory, we show a well-observed coronal jet event, in which the part of the jet with embedding coronal loops runs into a nearby coronal hole (CH) and gets bounced in the opposite direction. This is evidenced by the flat shape of the jet front during its interaction with the CH and the V-shaped feature in the time-slice plot of the interaction region. About a half-hour later, a CME with an initially narrow and jet-like front is observed by the LASCO C2 coronagraph propagating along the direction of the post-collision jet. We also observe some 304 Å dark material flowing from the jet–CH interaction region toward the CME. We thus suggest that the jet and the CME are physically connected, with the jet–CH collision and the large-scale magnetic topology of the CH being important in defining the eventual propagating direction of this particular jet–CME eruption.

  1. TRIGGER OF A BLOWOUT JET IN A SOLAR CORONAL MASS EJECTION ASSOCIATED WITH A FLARE

    SciTech Connect

    Li, Xiaohong; Yang, Shuhong; Chen, Huadong; Li, Ting; Zhang, Jun

    2015-11-20

    Using the multi-wavelength images and the photospheric magnetograms from the Solar Dynamics Observatory, we study the flare that was associated with the only coronal mass ejection (CME) in active region (AR) 12192. The eruption of a filament caused a blowout jet, and then an M4.0 class flare occurred. This flare was located at the edge of the AR instead of in the core region. The flare was close to the apparently “open” fields, appearing as extreme-ultraviolet structures that fan out rapidly. Due to the interaction between flare materials and “open” fields, the flare became an eruptive flare, leading to the CME. Then, at the same site of the first eruption, another small filament erupted. With the high spatial and temporal resolution Hα data from the New Vacuum Solar Telescope at the Fuxian Solar Observatory, we investigate the interaction between the second filament and the nearby “open” lines. The filament reconnected with the “open” lines, forming a new system. To our knowledge, the detailed process of this kind of interaction is reported for the first time. Then the new system rotated due to the untwisting motion of the filament, implying that the twist was transferred from the closed filament system to the “open” system. In addition, the twist seemed to propagate from the lower atmosphere to the upper layers and was eventually spread by the CME to the interplanetary space.

  2. Solar wind observations with the ion composition instrument aboard the ISEE-3/ICE spacecraft

    NASA Technical Reports Server (NTRS)

    Ogilvie, K. W.; Coplan, M. A.; Bochsler, P.; Geiss, J.

    1989-01-01

    The principal observations obtained by the Ion Composition Instrument (ICI) flown on the ISEE-3/ICE spacecraft, which was in the solar wind from September 1978 to the end of 1982, before being directed to the far magnetotail of the Earth are discussed. Almost continuous observations were made of the abundances of 3He++, 4He++, 06+, 07+, Ne, Si and Fe in various charge states, and of their bulk speeds and temperatures. The results show that there is a strong tendency in the collisionless solar wind for the ionic temperatures to be proportional to the masses. For heavier ions these temperatures exceed typical coronal electron temperatures. 4He++, especially in high speed streams, moves faster than H+, and travels at the same speed as heavier ions. The mechanism leading to this heating and rapid streaming is still not entirely clear.

  3. Solar wind observations with the ion composition instrument aboard the ISEE-3 ICE spacecraft

    NASA Technical Reports Server (NTRS)

    Ogilvie, K. W.; Coplan, M. A.; Bochsler, P.; Geiss, J.

    1989-01-01

    The principal observations obtained by the Ion Composition Instrument (ICI) flown on the ISEE-3/ICE spacecraft, which was in the solar wind from September 1978 to the end of 1982, before being directed to the far magnetotail of the Earth are discussed. Almost continuous observations were made of the abundances of 3He++, 4He++, O6+, O7+, Ne, Si and Fe in various charge states, and of their bulk speeds and temperatures. The results show that there is a strong tendency in the collisionless solar wind for the ionic temperatures to be proportional to the masses. For heavier ions these temperatures exceed typical coronal electron temperatures. 4He++, especially in high speed streams, moves faster than H+, and travels at the same speed as heavier ions. The mechanism leading to this heating and rapid streaming is still not entirely clear.

  4. A 17-billion-solar-mass black hole in a group galaxy with a diffuse core

    NASA Astrophysics Data System (ADS)

    Thomas, Jens; Ma, Chung-Pei; McConnell, Nicholas J.; Greene, Jenny E.; Blakeslee, John P.; Janish, Ryan

    2016-04-01

    Quasars are associated with and powered by the accretion of material onto massive black holes; the detection of highly luminous quasars with redshifts greater than z = 6 suggests that black holes of up to ten billion solar masses already existed 13 billion years ago. Two possible present-day ‘dormant’ descendants of this population of ‘active’ black holes have been found in the galaxies NGC 3842 and NGC 4889 at the centres of the Leo and Coma galaxy clusters, which together form the central region of the Great Wall—the largest local structure of galaxies. The most luminous quasars, however, are not confined to such high-density regions of the early Universe; yet dormant black holes of this high mass have not yet been found outside of modern-day rich clusters. Here we report observations of the stellar velocity distribution in the galaxy NGC 1600—a relatively isolated elliptical galaxy near the centre of a galaxy group at a distance of 64 megaparsecs from Earth. We use orbit superposition models to determine that the black hole at the centre of NGC 1600 has a mass of 17 billion solar masses. The spatial distribution of stars near the centre of NGC 1600 is rather diffuse. We find that the region of depleted stellar density in the cores of massive elliptical galaxies extends over the same radius as the gravitational sphere of influence of the central black holes, and interpret this as the dynamical imprint of the black holes.

  5. Propagation of Coronal Mass Ejections in 3D and the Structure of the Inner Heliosphere

    NASA Astrophysics Data System (ADS)

    Gallagher, P. T.; Byrne, J. P.; Maloney, S. A.; McAteer, J.

    2011-12-01

    Solar coronal mass ejections (CMEs) are the most significant drivers of adverse space weather on Earth, but the physics governing their propagation through the heliosphere is not well understood. Although stereoscopic imaging of CMEs with NASA's Solar Terrestrial Relations Observatory (STEREO) has provided some insight into their three-dimensional (3D) propagation, the mechanisms governing their evolution remain unclear because of difficulties in reconstructing their true 3D structure. In this talk I will describe the use of an elliptical tie-pointing technique to reconstruct a CME front in 3D, enabling us to quantify its deflected trajectory from high latitudes along the ecliptic, and measure its increasing angular width and propagation. At large distances from the Sun (>7 R_sun), I will describe how its motion is determined by drag effects in the solar wind, using ENLIL simulations of the inner heliosphere. By combining a 3D reconstruction with modelling of the solar wind, we predict an arrival time within 30 mins of the in-situ detection of the CME at ACE

  6. Multi-wavelength fine structure and mass flows in solar microflares

    NASA Astrophysics Data System (ADS)

    Berkebile-Stoiser, S.; Gömöry, P.; Veronig, A. M.; Rybák, J.; Sütterlin, P.

    2009-10-01

    Aims: We study the multi-wavelength characteristics at high spatial resolution, as well as chromospheric evaporation signatures of solar microflares. To this end, we analyze the fine structure and mass flow dynamics in the chromosphere, transition region and corona of three homologous microflares (GOES class solar spectroscopic imager (≳3 keV) was carried out. EUV line spectra provided by the coronal diagnostic spectrometer are searched for Doppler shifts in order to study associated plasma flows at chromospheric (He i, T˜3.9× 104 K), transition region (e.g. O v, T˜ 2.6× 105 K), and coronal temperatures (Si xii, T˜ 2× 106 K). RHESSI X-ray spectra provide information about non-thermal electrons. Results: The multi-wavelength appearance of the microflares is in basic agreement with the characteristics of large flares. For the first event, a complex flare sequence is observed in TRACE 17.1 nm images (T≈ 1 MK), which show several brightenings, narrow loops of enhanced emission, and an EUV jet. EIT 19.5 nm data (T≈ 1.5 MK) exhibit similar features for the third event. DOT measurements show finely structured chromospheric flare brightenings for all three events, loop-shaped fibrils of increased emission between Hα brightenings, as well as a similar feature in Ca ii. For all three events, a RHESSI X-ray source (3-8 keV, T ≳ 10 MK) is located in between two chromospheric brightenings situated in magnetic flux of opposite polarity. We find the flow dynamics associated with the events to be very complex. In the chromosphere and transition region, CDS observed downflows for the first (v ≲ 40 km s-1), and

  7. Solar wind control of the distant magnetotail: ISEE 3

    NASA Technical Reports Server (NTRS)

    Fairfield, D. H.

    1993-01-01

    During a 40-day period in 1983, International Sun Earth Explorer 3 (ISEE 3) was located about 225 R(sub E) behind the Earth and remained within 12 R(sub E) of the nominal tail axis. During this time the spacecraft spent at least 70% of its time in the magnetotail with occasional excursions into the magnetosheath. However, during five geomagnetically distrubed intervals of 1 - 3 days duration during this period, ISEE 3 remained within the magnetosheath for extended intervals, even when it was very near the center of an average tail. Simultaneous observations of the solar wind direction and thermal pressure suggest that nonradial solar wind flow associated with interacting solar wind streams moves a compressed tail away from the nominal position at these times and explains most of these observations. However, during several few-hour intervals of strongly northward interplanetary magnetic field (IMF) within these periods, the solar wind is more radial and cannot explain the residence of the spacecraft in the magnetosheath. At these times ISEE 3 seems to be moving back and forth between two regions, one a higher-density, lower-temperature magnetosheathlike region but with density somewhat lower than the normal magnetosheath, the other a lower-density, higher-temperature taillike region but with density higher than the normal tail. Both regions have larger B(sub z) components and B(sub x) components that tend to vary as if the spacecraft were moving from one hemisphere of the tail to the other. It is suggested that the magnetotail at these times of northward IMF consists mostly of field lines that close Earthward of the spacecraft with a narrow remaining tail at 225 R(sub E) waving back and forth across the spacecraft. If relatively rare intervals of long-duration, very northward IMF can eliminate the extended tail, it seems likely that more common, less northward IMF might well have very important, though less drastic, effects on the tail configurations.

  8. IS SOLAR CYCLE 24 PRODUCING MORE CORONAL MASS EJECTIONS THAN CYCLE 23?

    SciTech Connect

    Wang, Y.-M.; Colaninno, R. E-mail: robin.colaninno@nrl.navy.mil

    2014-04-01

    Although sunspot numbers are roughly a factor of two lower in the current cycle than in cycle 23, the rate of coronal mass ejections (CMEs) appears to be at least as high in 2011-2013 as during the corresponding phase of the previous cycle, according to three catalogs that list events observed with the Large Angle and Spectrometric Coronagraph (LASCO). However, the number of CMEs detected is sensitive to such factors as the image cadence and the tendency (especially by human observers) to under-/overcount small or faint ejections during periods of high/low activity. In contrast to the total number, the total mass of CMEs is determined mainly by larger events. Using the mass measurements of 11,000 CMEs given in the manual CDAW catalog, we find that the mass loss rate remains well correlated with the sunspot number during cycle 24. In the case of the automated CACTus and SEEDS catalogs, the large increase in the number of CMEs during cycle 24 is almost certainly an artifact caused by the near-doubling of the LASCO image cadence after mid-2010. We confirm that fast CMEs undergo a much stronger solar-cycle variation than slow ones, and that the relative frequency of slow and less massive CMEs increases with decreasing sunspot number. We conclude that cycle 24 is not only producing fewer CMEs than cycle 23, but that these ejections also tend to be slower and less massive than those observed one cycle earlier.

  9. Is Solar Cycle 24 Producing More Coronal Mass Ejections Than Cycle 23?

    NASA Astrophysics Data System (ADS)

    Wang, Y.-M.; Colaninno, R.

    2014-04-01

    Although sunspot numbers are roughly a factor of two lower in the current cycle than in cycle 23, the rate of coronal mass ejections (CMEs) appears to be at least as high in 2011-2013 as during the corresponding phase of the previous cycle, according to three catalogs that list events observed with the Large Angle and Spectrometric Coronagraph (LASCO). However, the number of CMEs detected is sensitive to such factors as the image cadence and the tendency (especially by human observers) to under-/overcount small or faint ejections during periods of high/low activity. In contrast to the total number, the total mass of CMEs is determined mainly by larger events. Using the mass measurements of 11,000 CMEs given in the manual CDAW catalog, we find that the mass loss rate remains well correlated with the sunspot number during cycle 24. In the case of the automated CACTus and SEEDS catalogs, the large increase in the number of CMEs during cycle 24 is almost certainly an artifact caused by the near-doubling of the LASCO image cadence after mid-2010. We confirm that fast CMEs undergo a much stronger solar-cycle variation than slow ones, and that the relative frequency of slow and less massive CMEs increases with decreasing sunspot number. We conclude that cycle 24 is not only producing fewer CMEs than cycle 23, but that these ejections also tend to be slower and less massive than those observed one cycle earlier.

  10. COMPARING SPATIAL DISTRIBUTIONS OF SOLAR PROMINENCE MASS DERIVED FROM CORONAL ABSORPTION

    SciTech Connect

    Gilbert, Holly; Kilper, Gary; Kucera, Therese; Alexander, David

    2011-01-20

    In a previous study, Gilbert et al. derived the column density and total mass of solar prominences using a new technique, which measures how much coronal radiation in the Fe XII (195 A) spectral band is absorbed by prominence material, while considering the effects of both foreground and background radiation. In the present work, we apply this method to a sample of prominence observations in three different wavelength regimes: one in which only H{sup 0} is ionized (504 A < {lambda} < 911 A), a second where both H{sup 0} and He{sup 0} are ionized (228 A < {lambda} < 504 A), and finally at wavelengths where H{sup 0}, He{sup 0}, and He{sup +} are all ionized ({lambda} < 228 A). This approach, first suggested by Kucera et al., permits the separation of the contributions of neutral hydrogen and helium to the total column density in prominences. Additionally, an enhancement of the technique allowed the calculation of the two-dimensional (2D) spatial distribution of the column density from the continuum absorption in each extreme-ultraviolet observation. We find the total prominence mass is consistently lower in the 625 A observations compared to lines in the other wavelength regimes. There is a significant difference in total mass between the 625 A and 195 A lines, indicating the much higher opacity at 625 A is causing a saturation of the continuum absorption and thus, a potentially large underestimation of mass.

  11. Solar-wind tritium limit and the mixing rate of the solar atmosphere. [from recovered Surveyor 3 parts

    NASA Technical Reports Server (NTRS)

    Fireman, E. L.

    1976-01-01

    Tritium has been measured, in Surveyor 3 samples, some of which were adjacent to those in which solar-wind-implanted He-4 had previously been measured. Little of the H-3 can be attributed to solar-wind implantation. The upper limit for the H-3/He-4 ratio in the solar wind is four times ten to the minus tenth power and corresponds to a H-3/H-1 limit of two times ten to the minus eleventh power. This limit imposes a requirement on the mixing rate in the solar atmosphere if the H-3 production rate in solar-surface nuclear reactions is greater than 160 sq cm/sec.

  12. Passive solar progress: a simplified guide to the 3rd national passive solar conference

    SciTech Connect

    Miller, H.; Howell, Y.; Richards, D.

    1980-10-01

    Some of the concepts and practices that have come to be known as passive solar heating and cooling are introduced, and a current picture of the field is presented. Much of the material presented is derived from papers given at the 3rd National Passive Solar Conference held in San Jose, California in January 1979 and sponsored by the US Department of Energy. Extracts and data from these papers have been integrated in the text with explanatory and descriptive material. In this way, it is attempted to present technical information in an introductory context. Topics include design considerations, passive and hybrid systems and applications, sizing methods and performance prediction, and implementation issues. A glossary is included. (WHK)

  13. Design and Performance of a Triple Source Air Mass Zero Solar Simulator

    NASA Technical Reports Server (NTRS)

    Jenkins, Phillip; Scheiman, David; Snyder, David

    2005-01-01

    Simulating the sun in a laboratory for the purpose of measuring solar cells has long been a challenge for engineers and scientists. Multi-junction cells demand higher fidelity of a solar simulator than do single junction cells, due to a need for close spectral matching as well as AM0 intensity. A GaInP/GaAs/Ge solar cell for example, requires spectral matching in three distinct spectral bands (figure 1). A commercial single source high-pressure xenon arc solar simulator such as the Spectrolab X-25 at NASA Glenn Research Center, can match the top two junctions of a GaInP/GaAs/Ge cell to within 1.3% mismatch, with the GaAs cell receiving slightly more current than required. The Ge bottom cell however, is mismatched +8.8%. Multi source simulators are designed to match the current for all junctions but typically have small illuminated areas, less uniformity and less beam collimation compared to an X-25 simulator. It was our intent when designing a multi source simulator to preserve as many aspects of the X-25 while adding multi-source capability.

  14. Solar carbon monoxide: poster child for 3D effects .

    NASA Astrophysics Data System (ADS)

    Ayres, T. R.; Lyons, J. R.; Ludwig, H.-G.; Caffau, E.; Wedemeyer-Böhm, S.

    Photospheric infrared (2-6 mu m) rovibrational bands of carbon monoxide (CO) provide a tough test for 3D convection models such as those calculated using CO5BOLD. The molecular formation is highly temperature-sensitive, and thus responds in an exaggerated way to thermal fluctuations in the dynamic atmosphere. CO, itself, is an important tracer of the oxygen abundance, a still controversial issue in solar physics; as well as the heavy isotopes of carbon (13C) and oxygen (18O, 17O), which, relative to terrestrial values, are fingerprints of fractionation processes that operated in the primitive solar nebula. We show how 3D models impact the CO line formation, and add in a second constraint involving the near-UV Ca RIPTSIZE II line wings, which also are highly temperature sensitive, but in the opposite sense to the molecules. We find that our reference CO5BOLD snapshots appear to be slightly too cool on average in the outer layers of the photosphere where the CO absorptions and Ca RIPTSIZE II wing emissions arise. We show, further, that previous 1D modeling was systematically biased toward higher oxygen abundances and lower isotopic ratios (e.g., R23equiv 12C/13C), suggesting an isotopically ``heavy'' Sun contrary to direct capture measurements of solar wind light ions by the Genesis Discovery Mission. New 3D ratios for the oxygen isotopes are much closer to those reported by Genesis, and the associated oxygen abundance from CO now is consistent with the recent Caffau et al. study of atomic oxygen. Some lingering discrepancies perhaps can be explained by magnetic bright points. Solar CO demonstrates graphically the wide gulf that can occur between a 3D analysis and 1D.

  15. ACRIM3 and the Total Solar Irradiance database

    NASA Astrophysics Data System (ADS)

    Willson, Richard C.

    2014-08-01

    The effects of scattering and diffraction on the observations of the ACRIMSAT/ACRIM3 satellite TSI monitoring mission have been characterized by the preflight calibration approach for satellite total solar irradiance (TSI) sensors implemented at the LASP/TRF (Laboratory for Atmospheric and Space Physics/Total Solar Irradiance Radiometer Facility). The TRF also calibrates the SI (International System of units) traceability to the NIST (National Institute of Standards and Technology) cryo-radiometric scale. ACRIM3's self-calibration agrees with NIST to within the uncertainty of the test procedure (˜500 ppm). A correction of ˜5000 ppm was found for scattering and diffraction that has significantly reduced the scale difference between the results of the ACRIMSAT/ACRIM3 and SORCE/TIM satellite experiments. Algorithm updates reflecting more than 10 years of mission experience have been made that further improve the ACRIM3 results by eliminating some thermally driven signal and increasing the signal to noise ratio. The result of these changes is a more precise and detailed picture of TSI variability. Comparison of the results from the ACRIM3, SORCE/TIM and SOHO/VIRGO satellite experiments demonstrate the near identical detection of TSI variability on all sub-annual temporal and amplitude scales during the TIM mission. The largest occurs at the rotational period of the primary solar activity longitudes. On the decadal timescale, while ACRIM3 and VIRGO results exhibit close agreement throughout, TIM exhibits a consistent 500 ppm upward trend relative to ACRIM3 and VIRGO. A solar magnetic activity area proxy for TSI has been used to demonstrate that the ACRIM TSI composite and its +0.037 %/decade TSI trend during solar cycles 21-23 is the most likely correct representation of the extant satellite TSI database. The occurrence of this trend during the last decades of the 20th century supports a more robust contribution of TSI variation to detected global temperature increase

  16. Altitude variations in the thermosphere mass density response to geomagnetic activity during the recent solar minimum

    NASA Astrophysics Data System (ADS)

    Liu, X.; Thayer, J. P.; Burns, A.; Wang, W.; Sutton, E.

    2014-03-01

    Accelerometer data from coplanar orbits of Challenging Minisatellite Payload (CHAMP) and Gravity Recovery and Climate Experiment (GRACE) satellites were used to study the complex altitude and latitude variations of the thermosphere mass density response to geomagnetic activity during 1-10 December 2008 near 09 LT. Helium number densities near 500 km altitude were extracted from the CHAMP and GRACE measurements and clearly show the presence of a winter hemisphere helium bulge. This recent extreme solar minimum indicates that wintertime helium concentrations exceed NRLMSISE-00 model estimates by 30%-70% during quiet geomagnetic activity after adjusting F10.7 input into MSIS. The perturbation in mass density from quiet to active conditions is found to be less enhanced in the winter hemisphere at the higher GRACE altitudes (25%) than at the lower CHAMP altitudes (60%) and is attributed to dynamic behavior in the helium/oxygen transition. The investigation revealed the maximum storm time density perturbation to occur near the He/O transition region with a much weaker maximum near the O/N2 transition region. The altitude of maximum density perturbation occurs where the perturbation in the weighted pressure scale height is equal and opposite to the perturbation in the weighted mean molecular weight scale height. The altitude structure of density scale height perturbation is significantly influenced by the changes in the molecular weight scale height and can account for 50% of the change in mass density scale height in a region correspondingly close to the He/O transition during the 2008 solar minimum period.

  17. Mass extinctions, galactic orbits in the solar neighborhood and the Sun: a connection?

    NASA Astrophysics Data System (ADS)

    Porto de Mello, G. F.; Dias, W. S.; Lépine, J. R. D.; Lorenzo-Oliveira, D.; Siqueira, R. K.

    2014-10-01

    The orbits of the stars in the disk of the Galaxy, and their passages through the Galactic spiral arms, are a rarely mentioned factor of biosphere stability which might be important for long-term planetary climate evolution, with a possible bearing on mass extinctions. The Sun lies very near the co-rotation radius, where stars revolve around the Galaxy in the same period as the density wave perturbations of the spiral arms. Conventional wisdom generally considers that this status makes for few passages through the spiral arms. Controversy still surrounds whether time spent inside or around spiral arms is dangerous to biospheres and conducive to mass extinctions. Possible threats include giant molecular clouds disturbing the Oort comet cloud and provoking heavy bombardment; a higher exposure to cosmic rays near star forming regions triggering increased cloudiness in Earth's atmosphere and ice ages; and the destruction of Earth's ozone layer posed by supernova explosions. We present detailed calculations of the history of spiral arm passages for all 212 solar-type stars nearer than 20 parsecs, including the total time spent inside the spiral arms in the last 500 Myr, when the spiral arm position can be traced with good accuracy. We found that there is a large diversity of stellar orbits in the solar neighborhood, and the time fraction spent inside spiral arms can vary from a few percent to nearly half the time. The Sun, despite its proximity to the galactic co-rotation radius, has exceptionally low eccentricity and a low vertical velocity component, and therefore spends 30% of its lifetime crossing the spiral arms, more than most nearby stars. We discuss the possible implications of this fact to the long-term habitability of the Earth, and possible correlations of the Sun's passage through the spiral arms with the five great mass extinctions of the Earth's biosphere from the Late Ordovician to the Cretaceous-Tertiary.

  18. An Investigation of the Large Scale Evolution and Topology of Coronal Mass Ejections in the Solar Wind

    NASA Technical Reports Server (NTRS)

    Riley, Peter

    2000-01-01

    This investigation is concerned with the large-scale evolution and topology of coronal mass ejections (CMEs) in the solar wind. During this reporting period we have focused on several aspects of CME properties, their identification and their evolution in the solar wind. The work included both analysis of Ulysses and ACE observations as well as fluid and magnetohydrodynamic simulations. In addition, we analyzed a series of "density holes" observed in the solar wind, that bear many similarities with CMEs. Finally, this work was communicated to the scientific community at three meetings and has led to three scientific papers that are in various stages of review.

  19. A Spectroscopic Examination of Accretion Diagnostics for Near Solar Mass Stars in IC 348

    NASA Astrophysics Data System (ADS)

    Dahm, S. E.

    2008-08-01

    High-resolution optical and moderate-resolution near-infrared spectra were obtained for 40 near solar mass (~2.0-0.5 M sun) members of the 2-3 Myr old cluster IC 348 in order to examine established accretion diagnostics and the coupling between inner disk gas and hot, micron-sized dust grains inferred from thermal and mid-infrared excesses. The stellar sample was drawn from the cluster census of Luhman in 2003 with membership being confirmed by radial velocity analysis and the presence of strong Li I λ6708 absorption. Of the stars included in this survey, 12 were classified by Lada in 2006 as hosting primordial, optically thick circumstellar disks, 5 as weak or transition disk systems, and 23 as non-excess stars using the measured slope of the stellar spectral energy distribution (SED) through the four Infrared Array Camera channels (3.6-8.0 μm) of Spitzer Space Telescope. Using the velocity width of Hα as an accretion indicator, we find that 11 primordial disk candidates are suspected accretors, suggesting a strong correlation between gaseous inner disks and optically thick dust emission. Of the five weak or transition disk systems observed, two (L21 and L67) exhibit spectroscopic features indicative of accretion. The presence of gas within the inner disk of these systems, which are free of infrared excess emission shortward of ~4.5 μm, may place constraints upon the physical mechanism responsible for inner disk clearing. Mass accretion rates (\\dot{M}) were determined for all suspected accretors using continuum excess measurements near λ6500 and established relationships between He I λ5876, Hα, Ca II λ8542, Paβ, and Brγ line fluxes and accretion luminosity. \\dot{M} values were found to range from log \\dot{M} = -8.7 to -7.2 M sun yr-1, with a median value of -8.1 M sun yr-1. Magnetospheric accretion models of Hα, Paβ, and Brγ emission by Muzerolle et al. and Kurosawa et al. are found to be in relative agreement with observed fluxes and derived \\dot

  20. Solar source regions of 3HE-rich particle events

    NASA Technical Reports Server (NTRS)

    Kahler, S. W.; Lin, R. P.; Reames, D. V.; Stone, R. G.; Liggett, M.

    1985-01-01

    Hydrogen alpha X-ray, and metric and kilometric radio data to examine the solar sources of energetic 3He-rich particle events observed near earth in association with impulsive 2 to 100 keV electron events were applied. Each 3He/electron event is associated with a kilometric type 3 burst belonging to a family of such bursts characterized by similar interplanetary propagation paths from the same solar active region. The 3He/electron events correlate very well with the interplanetary low frequency radio brightnesses of these events, but progressively worse with signatures from regions closer to the Sun. When H alpha brightnings can be associated with 3He/electron events, they have onsets coinciding to within 1 min of that of the associated metric type 3 burst but are often too small to be reported. The data are consistent with the earlier idea that many type 3 bursts, the 3He/electron events, are due to particle acceleration in the corona, well above the associated H alpha and X-ray flares.

  1. Solar Flares, Type III Radio Bursts, Coronal Mass Ejections, and Energetic Particles

    NASA Technical Reports Server (NTRS)

    Cane, Hilary V.; Erickson, W. C.; Prestage, N. P.; White, Nicholas E. (Technical Monitor)

    2002-01-01

    In this correlative study between greater than 20 MeV solar proton events, coronal mass ejections (CMEs), flares, and radio bursts it is found that essentially all of the proton events are preceded by groups of type III bursts and all are preceded by CMEs. These type III bursts (that are a flare phenomenon) usually are long-lasting, intense bursts seen in the low-frequency observations made from space. They are caused by streams of electrons traveling from close to the solar surface out to 1 AU. In most events the type III emissions extend into, or originate at, the time when type II and type IV bursts are reported (some 5 to 10 minutes after the start of the associated soft X-ray flare) and have starting frequencies in the 500 to approximately 100 MHz range that often get lower as a function of time. These later type III emissions are often not reported by ground-based observers, probably because of undue attention to type II bursts. It is suggested to call them type III-1. Type III-1 bursts have previously been called shock accelerated (SA) events, but an examination of radio dynamic spectra over an extended frequency range shows that the type III-1 bursts usually start at frequencies above any type II burst that may be present. The bursts sometimes continue beyond the time when type II emission is seen and, furthermore, sometimes occur in the absence of any type II emission. Thus the causative electrons are unlikely to be shock accelerated and probably originate in the reconnection regions below fast CMEs. A search did not find any type III-1 bursts that were not associated with CMEs. The existence of low-frequency type III bursts proves that open field lines extend from within 0.5 radius of the Sun into the interplanetary medium (the bursts start above 100 MHz, and such emission originates within 0.5 solar radius of the solar surface). Thus it is not valid to assume that only closed field lines exist in the flaring regions associated with CMEs and some

  2. Analysis of Solar Wind Samples Returned by Genesis Using Laser Post Ionization Secondary Neutral Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Veryovkin, I. V.; Calaway, W. F.; Tripa, C. E.; Pellin, M. J.; Burnett, D. S.

    2005-12-01

    A new secondary neutral mass spectrometry (SNMS) instrument implementing laser post ionization (LPI) of ion sputtered and laser desorbed neutral species has been developed and constructed for the specific purpose of quantitative analysis of metallic elements at ultra trace levels in solar wind collector samples returned to Earth by the Genesis Discovery mission. The first LPI SNMS measurements are focusing on determining Al, Ca, Cr, and Mg in these samples. These measurements provide the first concentration and isotopic abundances determinations for several key metallic elements and also elucidate possible fractionation effects between the photosphere and the solar wind compositions. It is now documented that Genesis samples suffered surface contamination both during flight and during the breach of the Sample Return Capsule when it crashed. Since accurate quantitative analysis is compromised by sample contamination, several features have been built into the new LPI SNMS instrument to mitigate this difficulty. A normally-incident, low-energy (<500 eV) ion beam combined with a keV energy ion beam and a desorbing laser beam (both microfocused) enables dual beam analyses. The low-energy ion beam can be used to remove surface contaminant by sputtering with minimum ion beam mixing. This low-energy beam also will be used to perform ion beam milling, while either the microfocused ion or laser beam probes the solar wind elemental compositions as a function of sample depth. Because of the high depth resolution of dual beam analyses, such depth profiles clearly distinguish between surface contaminants and solar wind implanted atoms. In addition, in-situ optical and electron beam imaging for observing and avoiding particulates and scratches on solar wind sample surfaces is incorporated in the new LPI SNMS instrument to further reduce quantification problems. The current status of instrument tests and analyses will be presented. This work is supported by the U. S. Department of

  3. An ultraluminous quasar with a twelve-billion-solar-mass black hole at redshift 6.30.

    PubMed

    Wu, Xue-Bing; Wang, Feige; Fan, Xiaohui; Yi, Weimin; Zuo, Wenwen; Bian, Fuyan; Jiang, Linhua; McGreer, Ian D; Wang, Ran; Yang, Jinyi; Yang, Qian; Thompson, David; Beletsky, Yuri

    2015-02-26

    So far, roughly 40 quasars with redshifts greater than z = 6 have been discovered. Each quasar contains a black hole with a mass of about one billion solar masses (10(9) M Sun symbol). The existence of such black holes when the Universe was less than one billion years old presents substantial challenges to theories of the formation and growth of black holes and the coevolution of black holes and galaxies. Here we report the discovery of an ultraluminous quasar, SDSS J010013.02+280225.8, at redshift z = 6.30. It has an optical and near-infrared luminosity a few times greater than those of previously known z > 6 quasars. On the basis of the deep absorption trough on the blue side of the Lyman-α emission line in the spectrum, we estimate the proper size of the ionized proximity zone associated with the quasar to be about 26 million light years, larger than found with other z > 6.1 quasars with lower luminosities. We estimate (on the basis of a near-infrared spectrum) that the black hole has a mass of ∼1.2 × 10(10) M Sun symbol, which is consistent with the 1.3 × 10(10) M Sun symbol derived by assuming an Eddington-limited accretion rate.

  4. SOLAR CYCLE VARIATIONS OF CORONAL NULL POINTS: IMPLICATIONS FOR THE MAGNETIC BREAKOUT MODEL OF CORONAL MASS EJECTIONS

    SciTech Connect

    Cook, G. R.; Mackay, D. H.; Nandy, Dibyendu E-mail: duncan@mcs.st-and.ac.u

    2009-10-20

    In this paper, we investigate the solar cycle variation of coronal null points and magnetic breakout configurations in spherical geometry, using a combination of magnetic flux transport and potential field source surface models. Within the simulations, a total of 2843 coronal null points and breakout configurations are found over two solar cycles. It is found that the number of coronal nulls present at any time varies cyclically throughout the solar cycle, in phase with the flux emergence rate. At cycle maximum, peak values of 15-17 coronal nulls per day are found. No significant variation in the number of nulls is found from the rising to the declining phase. This indicates that the magnetic breakout model is applicable throughout both phases of the solar cycle. In addition, it is shown that when the simulations are used to construct synoptic data sets, such as those produced by Kitt Peak, the number of coronal nulls drops by a factor of 1/6. The vast majority of the coronal nulls are found to lie above the active latitudes and are the result of the complex nature of the underlying active region fields. Only 8% of the coronal nulls are found to be connected to the global dipole. Another interesting feature is that 18% of coronal nulls are found to lie above the equator due to cross-equatorial interactions between bipoles lying in the northern and southern hemispheres. As the majority of coronal nulls form above active latitudes, their average radial extent is found to be in the low corona below 1.25 R {sub sun} (175, 000 km above the photosphere). Through considering the underlying photospheric flux, it is found that 71% of coronal nulls are produced though quadrupolar flux distributions resulting from bipoles in the same hemisphere interacting. When the number of coronal nulls present in each rotation is compared to the number of bipoles emerging, a wide scatter is found. The ratio of coronal nulls to emerging bipoles is found to be approximately 1/3. Overall

  5. Nonlinear stability of solar type 3 radio bursts. 1: Theory

    NASA Technical Reports Server (NTRS)

    Smith, R. A.; Goldstein, M. L.; Papadopoulos, K.

    1978-01-01

    A theory of the excitation of solar type 3 bursts is presented. Electrons initially unstable to the linear bump-in-tail instability are shown to rapidly amplify Langmuir waves to energy densities characteristic of strong turbulence. The three-dimensional equations which describe the strong coupling (wave-wave) interactions are derived. For parameters characteristic of the interplanetary medium the equations reduce to one dimension. In this case, the oscillating two stream instability (OTSI) is the dominant nonlinear instability, and is stablized through the production of nonlinear ion density fluctuations that efficiently scatter Langmuir waves out of resonance with the electron beam. An analytical model of the electron distribution function is also developed which is used to estimate the total energy losses suffered by the electron beam as it propagates from the solar corona to 1 A.U. and beyond.

  6. Solar Source Regions of Energetic 3He Emission

    NASA Astrophysics Data System (ADS)

    Mason, G. M.; Nitta, N. V.; Cohen, C. M.; Wiedenbeck, M. E.

    2012-12-01

    One of the surprising observations from the ACE mission has been the detection of energetic 3He emission occurring over multi-day periods. Previously observations of solar energetic 3He had detected short-lived "impulsive" energetic particle events which were associated with type III bursts and energetic electrons. The ACE observations were able to detect 3He at very low levels (<1% of 4He compared to ~10% in most earlier work) and this showed that the impulsive events often occurred during seemingly continuous multi-day periods of 3He emission. During solar active periods, 3He was present at 1 AU the majority of the time, giving evidence for either semi-continuous processes or else unresolved multiple small injections. The obvious injections during such periods were strongly associated with jet activity By adding STEREO and SDO observations we are seeking to extend the observational picture for these events. First, by following single 3He emitting regions from STEREO-B to ACE to STEREO-A we seek to examine for how long the 3He emission can continue, since any single spacecraft can be magnetically connected to a single region for only a few days and ACE often sees emission periods of that length. Second, by using SDO-AIA we seek to probe further the properties of the emitting regions to see if the previously reported association with jets is seen in events which we can now observe with greater resolution, sensitivity, and cadence than previously possible.

  7. Flare Particle Escape in 3D Solar Eruptive Events

    NASA Astrophysics Data System (ADS)

    Antiochos, Spiro K.; Masson, Sophie; DeVore, C. R.

    2015-04-01

    Among the most important, but least understood forms of space weather are the so-called Impulsive Solar Energetic Particle (SEP) events, which can be especially hazardous to deep-space astronauts. These energetic particles are generally believed to be produced by the flare reconnection that is the primary driver of solar eruptive events (SEE). A key point is that in the standard model of SEEs, the particles should remain trapped in the coronal flare loops and in the ejected plasmoid, the CME. However, flare-accelerated particles frequently reach the Earth long before the CME does. In previous 2.5D calculations we showed how the external reconnection that is an essential element of the breakout model for CME initiation could lead to the escape of flare-accelerated particles. The problem, however, is that in 2.5D this reconnection also tends to destroy the plasmoid, which disagrees with the observation that SEP events are often associated with well-defined plasmoids at 1 AU known as “magnetic clouds”. Consequently, we have extended our model to a fully 3D topology that includes a multi-polar coronal field suitable for a breakout SEE near a coronal hole region. We performed high-resolution 3D MHD numerical simulations with the Adaptively Refined MHD Solver (ARMS). Our results demonstrate that the model allows for the effective escape of energetic particles from deep within an ejecting well-defined plasmoid. We show how the complex interactions between the flare and breakout reconnection reproduce all the main observational features of SEEs and SEPs. We discuss the implications of our calculations for the upcoming Solar Orbiter and Solar Probe Plus missions, which will measure SEEs and SEPs near the Sun, thereby, mitigating propagation effects.This research was supported, in part, by the NASA SR&T and TR&T Programs.

  8. Solar and interplanetary activities of isolated and non-isolated coronal mass ejections

    NASA Astrophysics Data System (ADS)

    Bendict Lawrance, M.; Shanmugaraju, A.; Moon, Y.-J.; Umapathy, S.

    2017-02-01

    We report our results on comparison of two halo Coronal Mass Ejections (CME) associated with X-class flares of similar strength (X1.4) but quite different in CME speed and acceleration, similar geo-effectiveness but quite different in Solar Energetic Particle (SEP) intensity. CME1 (non-isolated) was associated with a double event in X-ray flare and it was preceded by another fast halo CME of speed = 2684 km/s (pre-CME) associated with X-ray flare class X5.4 by 1 h from the same location. Since this pre-CME was more eastern, interaction with CME1 and hitting the earth were not possible. This event (CME1) has not suffered the cannibalism since pre-CME has faster speed than post-CME. Pre-CME plays a very important role in increasing the intensity of SEP and Forbush Decrease (FD) by providing energetic seed particles. So, the seed population is the major difference between these two selected events. CME2 (isolated) was a single event. We would like to address on the kinds of physical conditions related to such CMEs and their associated activities. Their associated activities such as, type II bursts, SEP, geomagnetic storm and FD are compared. The following results are obtained from the analysis. (1) The CME leading edge height at the start of metric/DH type II bursts are 2 R⊙/ 4 R⊙ for CME1, but 2 R⊙/ 2.75 R⊙ for CME2. (2) Peak intensity of SEP event associated with the two CMEs are quite different: 6530 pfu for CME1, but 96 pfu for CME2. (3) The Forbush decrease occurred with a minimum decrease of 9.98% in magnitude for CME1, but 6.90% for CME2. (4) These two events produced similar intense geomagnetic storms of intensity of Dst index -130 nT. (5) The maximum southward magnetic fields corresponding to Interplanetary CME (ICME) of these two events are nearly the same, but there is difference in Sheath Bz maximum (-14.2, -6.9 nT). (6) The time-line chart of the associated activities of two CMEs show some difference in the time delay between the onsets of

  9. Obtaining the Mass and Radius of Extra-Solar Giant Planets

    NASA Technical Reports Server (NTRS)

    Castellano, Tim; Mead, Susan (Technical Monitor)

    1998-01-01

    The scientific utility and feasibility of detecting transits of the 9 known extrasolar planets is explored. A transit of a solar-like star by a Jupiter mass planet produces a 1% decrease in the amount of light received from the star. Transit observation will remove the ambiguity in the measurement of the planetary mass inherent in the radial velocity method and confirm the planet's existence. The 9 known planets have a 33% chance of producing at least one observable transit. Additional extrasolar planet detections from the radial velocity surveys will increase this probability to greater than 90%. The radius of the planet can be determined by the fractional decrease in light received during transit. The mass and radius may distinguish rocky or gas giant planets from brown dwarfs. The probability of detection, the transit signal size and duration, and predictions of the transit times (including errors) are calculated for circular and elliptical orbits. Observational limits are investigated and it is shown that small telescopes and existing detectors are adequate enough to achieve the 0.1% photometry necessary to detect transits of the known extrasolar planets.

  10. Characteristic Times of Gradual Solar Energetic Particle Events and Their Dependence on Associated Coronal Mass Ejection Properties

    DTIC Science & Technology

    2005-08-01

    2. REPORT TYPE 3. DATES COVERED (From - To) 01-08-2005 REPRINT 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Characteristic Times of Gradual Solar ...coronagraph on SOHO observed during 1998-2002 to statistically determine three characteristic times of gradual solar energetic particle (SEP) events as...functions of solar source longitude: (1) To, the time from associated CME launch to SEP onset at I AU, (2) TR, the rise time from SEO onset to the time when

  11. Interoperable Solar Data and Metadata via LISIRD 3

    NASA Astrophysics Data System (ADS)

    Wilson, A.; Lindholm, D. M.; Pankratz, C. K.; Snow, M. A.; Woods, T. N.

    2015-12-01

    LISIRD 3 is a major upgrade of the LASP Interactive Solar Irradiance Data Center (LISIRD), which serves several dozen space based solar irradiance and related data products to the public. Through interactive plots, LISIRD 3 provides data browsing supported by data subsetting and aggregation. Incorporating a semantically enabled metadata repository, LISIRD 3 users see current, vetted, consistent information about the datasets offered. Users can now also search for datasets based on metadata fields such as dataset type and/or spectral or temporal range. This semantic database enables metadata browsing, so users can discover the relationships between datasets, instruments, spacecraft, mission and PI. The database also enables creation and publication of metadata records in a variety of formats, such as SPASE or ISO, making these datasets more discoverable. The database also enables the possibility of a public SPARQL endpoint, making the metadata browsable in an automated fashion. LISIRD 3's data access middleware, LaTiS, provides dynamic, on demand reformatting of data and timestamps, subsetting and aggregation, and other server side functionality via a RESTful OPeNDAP compliant API, enabling interoperability between LASP datasets and many common tools. LISIRD 3's templated front end design, coupled with the uniform data interface offered by LaTiS, allows easy integration of new datasets. Consequently the number and variety of datasets offered by LISIRD has grown to encompass several dozen, with many more to come. This poster will discuss design and implementation of LISIRD 3, including tools used, capabilities enabled, and issues encountered.

  12. Depletion region effect of highly efficient hole conductor free CH3NH3PbI3 perovskite solar cells.

    PubMed

    Aharon, Sigalit; Gamliel, Shany; El Cohen, Bat; Etgar, Lioz

    2014-06-14

    The inorganic-organic perovskite is currently attracting a lot of attention due to its use as a light harvester in solar cells. The large absorption coefficients, high carrier mobility and good stability of organo-lead halide perovskites present good potential for their use as light harvesters in mesoscopic heterojunction solar cells. This work concentrated on a unique property of the lead halide perovskite, its function simultaneously as a light harvester and a hole conductor in the solar cell. A two-step deposition technique was used to optimize the perovskite deposition and to enhance the solar cell efficiency. It was revealed that the photovoltaic performance of the hole conductor free perovskite solar cell is strongly dependent on the depletion layer width which was created at the TiO2-CH3NH3PbI3 junction. X-ray diffraction measurements indicate that there were no changes in the crystallographic structure of the CH3NH3PbI3 perovskite over time, which supports the high stability of these hole conductor free perovskite solar cells. Furthermore, the power conversion efficiency of the best cells reached 10.85% with a fill factor of 68%, a Voc of 0.84 V, and a Jsc of 19 mA cm(-2), the highest efficiency to date of a hole conductor free perovskite solar cell.

  13. DIRECT OBSERVATIONS OF MAGNETIC FLUX ROPE FORMATION DURING A SOLAR CORONAL MASS EJECTION

    SciTech Connect

    Song, H. Q.; Chen, Y.; Zhang, J.; Cheng, X.

    2014-09-10

    Coronal mass ejections (CMEs) are the most spectacular eruptive phenomena in the solar atmosphere. It is generally accepted that CMEs are the results of eruptions of magnetic flux ropes (MFRs). However, there is heated debate on whether MFRs exist prior to the eruptions or if they are formed during the eruptions. Several coronal signatures, e.g., filaments, coronal cavities, sigmoid structures, and hot channels (or hot blobs), are proposed as MFRs and observed before the eruption, which support the pre-existing MFR scenario. There is almost no reported observation of MFR formation during the eruption. In this Letter, we present an intriguing observation of a solar eruptive event that occurred on 2013 November 21 with the Atmospheric Imaging Assembly on board the Solar Dynamic Observatory, which shows the formation process of the MFR during the eruption in detail. The process began with the expansion of a low-lying coronal arcade, possibly caused by the flare magnetic reconnection underneath. The newly formed ascending loops from below further pushed the arcade upward, stretching the surrounding magnetic field. The arcade and stretched magnetic field lines then curved in just below the arcade vertex, forming an X-point. The field lines near the X-point continued to approach each other and a second magnetic reconnection was induced. It is this high-lying magnetic reconnection that led to the formation and eruption of a hot blob (∼10 MK), presumably an MFR, producing a CME. We suggest that two spatially separated magnetic reconnections occurred in this event, which were responsible for producing the flare and the hot blob (CME)

  14. Homologous Jet-driven Coronal Mass Ejections from Solar Active Region 12192

    NASA Astrophysics Data System (ADS)

    Panesar, Navdeep K.; Sterling, Alphonse C.; Moore, Ronald L.

    2016-05-01

    We report observations of homologous coronal jets and their coronal mass ejections (CMEs) observed by instruments onboard the Solar Dynamics Observatory (SDO) and the Solar and Heliospheric Observatory (SOHO) spacecraft. The homologous jets originated from a location with emerging and canceling magnetic field at the southeastern edge of the giant active region (AR) of 2014 October, NOAA 12192. This AR produced in its interior many non-jet major flare eruptions (X- and M- class) that made no CME. During October 20 to 27, in contrast to the major flare eruptions in the interior, six of the homologous jets from the edge resulted in CMEs. Each jet-driven CME (˜200-300 km s-1) was slower-moving than most CMEs, with angular widths (20°-50°) comparable to that of the base of a coronal streamer straddling the AR and were of the “streamer-puff” variety, whereby the preexisting streamer was transiently inflated but not destroyed by the passage of the CME. Much of the transition-region-temperature plasma in the CME-producing jets escaped from the Sun, whereas relatively more of the transition-region plasma in non-CME-producing jets fell back to the solar surface. Also, the CME-producing jets tended to be faster and longer-lasting than the non-CME-producing jets. Our observations imply that each jet and CME resulted from reconnection opening of twisted field that erupted from the jet base and that the erupting field did not become a plasmoid as previously envisioned for streamer-puff CMEs, but instead the jet-guiding streamer-base loop was blown out by the loop’s twist from the reconnection.

  15. Spectroscopic Observations of a Solar Flare and the Associated Coronal Mass Ejection

    NASA Astrophysics Data System (ADS)

    Murray, S.; Tian, H.; McKillop, S.

    2013-12-01

    We used data from the EUV Imaging Spectrometer (EIS) on board Hinode to examine a coronal mass ejection and a preceding flare observed on 21 November 2012 between 15:00 and 17:00 UT. Images from the Atmospheric Imaging Assembly on the Solar Dynamics Observatory were used to align the data from EIS with specific events occurring. We analyzed spectra of a few emission lines at three locations on the flare site and one location in the erupting prominence. On the flare site, we found line profiles showing typical characteristics of chromospheric evaporation: downflows at cooler lines and upflows at hotter lines. At one particular location on the flare site, we clearly identified dominant downflows on the order of 100 km/s in lines through Fe VIII to Fe XVI. To the best of our knowledge, this is the first time that such strong high-speed downflows have been spectroscopically observed in the impulsive phase of solar flares. The profile of the Fe VIII 184.54 line reveals two peaks and we were able to use the double Gaussian fit to separate the rapid downflows of dense material from the nearly stationary coronal background emission. For the erupting prominence, we were able to analyze multiple lines, cooler and warmer, of interest using this double Gaussian fit to separate the background emission from the emission of the ejected material. Our results show that the LOS velocities of the ejected material are about 100 km/s in the lower corona. Additionally, in each region of interest, we used the ratio of the density-sensitive line pair FeXII 195/186 to determine the electron density. Our results clearly show that the coronal densities were greatly enhanced during the flare. The density of the ejected material is also much larger than the typical coronal density. This research was supported by the NSF grant for the Solar Physics REU Program at the Smithsonian Astrophysical Observatory (AGS-1263241).

  16. Multipoint Observations of Coronal Mass Ejection and Solar Energetic Particle Events on Mars and Earth During November 2001

    NASA Technical Reports Server (NTRS)

    Falkenberg, T. V.; Vennerstrom, S.; Brain, D. A.; Delory, G.; Taktakishvili, A.

    2011-01-01

    Multipoint spacecraft observations provide unique opportunities to constrain the propagation and evolution of interplanetary coronal mass ejections (ICMEs) throughout the heliosphere. Using Mars Global Surveyor (MGS) data to study both ICME and solar energetic particle (SEP) events at Mars and OMNI and Geostationary Operational Environmental Satellite (GOES) data to study ICMEs and SEPs at Earth, we present a detailed study of three CMEs and flares in late November 2001. In this period, Mars trailed Earth by 56deg solar longitude so that the two planets occupied interplanetary magnetic field lines separated by only approx.25deg. We model the interplanetary propagation of CME events using the ENLIL version 2.6 3-D MHD code coupled with the Wang-Sheeley-Arge version 1.6 potential source surface model, using Solar and Heliospheric Observatory (SOHO) Large Angle and Spectrometric Coronagraph (LASCO) images to determine CME input parameters. We find that multipoint observations are essential to constrain the simulations of ICME propagation, as two very different ICMEs may look very similar in only one observational location. The direction and width of the CME as parameters essential to a correct estimation of arrival time and amplitude of the ICME signal. We find that these are problematic to extract from the analysis of SOHO/LASCO images commonly used for input to ICME propagation models. We further confirm that MGS magnetometer and electron reflectometer data can be used to study not only ICME events but also SEP events at Mars, with good results providing a consistent picture of the events when combined with near-Earth data.

  17. Hybrid solar cells from P3HT and silicon nanocrystals.

    PubMed

    Liu, Chin-Yi; Holman, Zachary C; Kortshagen, Uwe R

    2009-01-01

    We are reporting new hybrid solar cells based on blends of silicon nanocrystals (Si NCs) and poly-3(hexylthiophene) (P3HT) polymer in which a percolating network of the nanocrystals acts as the electron-conducting phase. The properties of composite Si NCs/P3HT devices made by spin-coating Si NCs and P3HT from a common solvent were studied as a function of Si NC size and Si NC/P3HT ratio. The open-circuit voltage and short-circuit current are observed to depend on the Si NC size due to changes in the bandgap and surface-area-to-volume ratio. Under simulated one-sun A.M. 1.5 direct illumination (100 mW/cm2), devices made with 35 wt % Si NCs 3-5 nm in size showed 1.15% power conversion efficiency.

  18. Injection profiles of solar energetic particles as functions of coronal mass ejection heights

    NASA Technical Reports Server (NTRS)

    Kahler, S.

    1994-01-01

    Previous studies with Skylab and Solwind coronal mass ejections (CMEs) have shown that nearly all large E greater than 10 MeV solar energetic particle (SEP) events are associated with fast (v greater than 400 km/sec) CMEs. We compare heights of CMEs observed on the SMM spacecraft with the flux-time profiles of five associated SEP events observed by the GOES spacecraft, including three events observed as ground-level events (GLEs) by neutron monitors. The SEP injection profiles as functions of the CME heights are estimated from the 'solar release times' and the effects of interplanetary scattering. We find that the peaks of the 470 MeV to 4 GeV injection profiles of the GLEs occur when CME heights reach 5 to 15 R(sub 0) or greater and that the onsets occur no earlier than the maxima of the flare impulsive phases. In those events SEP injection appears to result only from a single CME-driven shock and not from the flare impulsive phase or from separate coronal and interplanetary shocks. In one small SEP event an impulsive flux-time profile is consistent with injection during the flare impulsive phase but could also be due to injection from a coronal shock over a limited time.

  19. CORONAL MASS EJECTIONS AND THE SOLAR CYCLE VARIATION OF THE SUN’S OPEN FLUX

    SciTech Connect

    Wang, Y.-M.; Sheeley, N. R. Jr. E-mail: neil.sheeley@nrl.navy.mil

    2015-08-20

    The strength of the radial component of the interplanetary magnetic field (IMF), which is a measure of the Sun’s total open flux, is observed to vary by roughly a factor of two over the 11 year solar cycle. Several recent studies have proposed that the Sun’s open flux consists of a constant or “floor” component that dominates at sunspot minimum, and a time-varying component due to coronal mass ejections (CMEs). Here, we point out that CMEs cannot account for the large peaks in the IMF strength which occurred in 2003 and late 2014, and which coincided with peaks in the Sun’s equatorial dipole moment. We also show that near-Earth interplanetary CMEs, as identified in the catalog of Richardson and Cane, contribute at most ∼30% of the average radial IMF strength even during sunspot maximum. We conclude that the long-term variation of the radial IMF strength is determined mainly by the Sun’s total dipole moment, with the quadrupole moment and CMEs providing an additional boost near sunspot maximum. Most of the open flux is rooted in coronal holes, whose solar cycle evolution in turn reflects that of the Sun’s lowest-order multipoles.

  20. COMBINED STEREO/RHESSI STUDY OF CORONAL MASS EJECTION ACCELERATION AND PARTICLE ACCELERATION IN SOLAR FLARES

    SciTech Connect

    Temmer, M.; Veronig, A. M.; Krucker, S.; Vrsnak, B. E-mail: asv@igam.uni-graz.a E-mail: krucker@ssl.berkeley.ed

    2010-04-01

    Using the potential of two unprecedented missions, Solar Terrestrial Relations Observatory (STEREO) and Reuven Ramaty High-Energy Solar Spectroscopic Imager (RHESSI), we study three well-observed fast coronal mass ejections (CMEs) that occurred close to the limb together with their associated high-energy flare emissions in terms of RHESSI hard X-ray (HXR) spectra and flux evolution. From STEREO/EUVI and STEREO/COR1 data, the full CME kinematics of the impulsive acceleration phase up to {approx}4 R{sub sun} is measured with a high time cadence of <=2.5 minutes. For deriving CME velocity and acceleration, we apply and test a new algorithm based on regularization methods. The CME maximum acceleration is achieved at heights h <= 0.4 R{sub sun}, and the peak velocity at h <= 2.1 R{sub sun} (in one case, as small as 0.5 R{sub sun}). We find that the CME acceleration profile and the flare energy release as evidenced in the RHESSI HXR flux evolve in a synchronized manner. These results support the 'standard' flare/CME model which is characterized by a feedback relationship between the large-scale CME acceleration process and the energy release in the associated flare.

  1. Type 3 solar radio bursts and 3HE-rich events

    NASA Technical Reports Server (NTRS)

    Reames, D. V.; Stone, R. G.

    1985-01-01

    The kilometric radio data for 3He-rich events during the 1979 to 82 time period were investigated. Type 3 bursts are present for each event as expected from the prevous electron 3He-event association. A list of identified solar events is presented.

  2. The Solar Mass Ejection Imager Optics and Baffles: Design and Construction

    NASA Astrophysics Data System (ADS)

    Jackson, Bernard V.; Buffington, Andrew; Hick, P. P.

    2000-11-01

    The purpose of SMEI is a proof-of-concept of the ability to predict geomagnetic disturbances for Air Force space operations and to establish the feasibility of tracking interplanetary disturbances from the Sun to the Earth and beyond. The major subsystems of SMEI are an electronic Camera Assembly, a Data Handling Unit and interconnection harnesses. Each electronic Camera component consists of a baffle, radiator, bright object sensor, strongbox (CCD, mirrors and shutter) and electronics box. The electronic Camera Assembly is used to observe in visible light mass ejections from the Sun by sensing sunlight scattered from clouds of solar-produced interplanetary electrons. Predictions of arrival time at Earth of this disturbance can be made up to three days in advance.

  3. The evolution of rotating stars. 1: Method and exploratory calculations for a 7 solar mass star

    NASA Technical Reports Server (NTRS)

    Endal, A. S.; Sofia, S.

    1976-01-01

    A method was developed which allows us to study the evolution of rotating stars beyond the main sequence stage. Four different cases of redistribution of angular momentum in an evolving star are considered. Evolutionary sequences for a 7 solar mass star, rotating according to these different cases, were computed from the ZAMS to the double shell source stage. Each sequence was begun with a (typical) equatorial velocity of 210 km/sec. On the main sequence, the effects of rotation are of minor importance. As the core contracts during later stages, important effects arise in all physically plausible cases. The outer regions of the cores approach critical velocities and develop unstable angular velocity distributions. The effects of these instabilities should significantly alter the subsequent evolution.

  4. Low Solar Wind Density Causing the Fast Coronal Mass Ejection from 23 July 2012

    NASA Astrophysics Data System (ADS)

    Nitta, N.; Temmer, M.

    2015-12-01

    The fast coronal mass ejection (CME) from July 23, 2012 raised special attention due to its short propagation time of less than 21hrs from Sun to 1 AU. In-situ data from STEREO-A revealed the arrival of a fast forward shock having a velocity of more than 2200 km/s followed by a magnetic structure with a speed of almost 1900 km/s. We study the evolution of the CME in interplanetary (IP) space using the drag based model to reproduce the short propagation time and high impact speed as derived from in-situ data. We find that the ambient density must have been exceptionally low due to which the drag force is reduced such that the CME experienced almost no deceleration. The density is found to be rather low due to the weak solar activity and was lowered even more by a previous CME event.

  5. A linear MHD instability analysis of solar mass ejections with gravitation

    NASA Technical Reports Server (NTRS)

    Song, M. T.; Wu, S. T.; Dryer, M.

    1987-01-01

    The linear MHD instability of a cylindrical plasma is used to investigate the origin of solar mass ejections, and the dispersion relation is solved numerically. The initial plasma-flow velocity is found to have a significant effect on the instability criteria and growth rate, and the instability growth-rate is shown to be larger in cases where plasma flow exists, relative to the static case. Results suggest that the plasma column may break into small pieces. Assuming a thin-tube approximation, gravity is found to have little effect on the instability of quasi-horizontal ejection, but to have considerable effect on the vertical ejection. In considering the gravitational force, an exact analytical solution is found for the vertical case, while asymptotic solutions are given for the horizontal and oblique cases.

  6. Mass transport, corrosion, plugging, and their reduction in solar dish/Stirling heat pipe receivers

    SciTech Connect

    Adkins, D.R.; Andraka, C.E.; Bradshaw, R.W.; Goods, S.H.; Moreno, J.B.; Moss, T.A.

    1996-07-01

    Solar dish/Stirling systems using sodium heat pipe receivers are being developed by industry and government laboratories here and abroad. The unique demands of this application lead to heat pipe wicks with very large surface areas and complex three-dimensional flow patterns. These characteristics can enhance the mass transport and concentration of constituents of the wick material, resulting in wick corrosion and plugging. As the test times for heat pipe receivers lengthen, we are beginning to see these effects both indirectly, as they affect performance, and directly in post-test examinations. We are also beginning to develop corrective measures. In this paper, we report on our test experiences, our post-test examinations, and on our initial effort to ameliorate various problems.

  7. EVIDENCE OF POSTERUPTION RECONNECTION ASSOCIATED WITH CORONAL MASS EJECTIONS IN THE SOLAR WIND

    NASA Technical Reports Server (NTRS)

    Riley, Pete; Linker, J. A.; Mikic, Z.; Odstracil, D.; Pizzo, V. J.; Webb, D. F.

    2002-01-01

    Using a coupled 2.5-dimensional, time-dependent MHD model of the solar corona and inner heliosphere, we have simulated the eruption and evolution of a coronal mass ejection containing a flux rope all the way from the Sun to 1 AU. Although idealized, we find that the simulation reproduces many generic features of magnetic clouds. In this paper we report on a new, intriguing aspect of these comparisons. Specifically, the results suggest that jetted outflow, driven by posteruptive reconnection underneath the flux rope, occurs and may remain intact out to 1 AU and beyond. We present an example of a magnetic cloud with precisely these signatures and show that the velocity perturbations are consistent with reconnection outflow. We suggest that other velocity and/or density enhancements observed trailing magnetic clouds may be signatures of such reconnection and, in some cases, may not be associated with prominence material, as has previously been suggested.

  8. ON THE ENHANCED CORONAL MASS EJECTION DETECTION RATE SINCE THE SOLAR CYCLE 23 POLAR FIELD REVERSAL

    SciTech Connect

    Petrie, G. J. D.

    2015-10-10

    Compared to cycle 23, coronal mass ejections (CMEs) with angular widths >30° have been observed to occur at a higher rate during solar cycle 24, per sunspot number. This result is supported by data from three independent databases constructed using Large Angle and Spectrometric Coronagraph Experiment coronagraph images, two employing automated detection techniques and one compiled manually by human observers. According to the two databases that cover a larger field of view, the enhanced CME rate actually began shortly after the cycle 23 polar field reversal, in 2004, when the polar fields returned with a 40% reduction in strength and the interplanetary radial magnetic field became ≈30% weaker. This result is consistent with the link between anomalous CME expansion and the heliospheric total pressure decrease recently reported by Gopalswamy et al.

  9. Near infrared emission of TbAG:Ce3+,Yb3+ phosphor for solar cell applications

    NASA Astrophysics Data System (ADS)

    Meshram, N. D.; Yadav, P. J.; Pathak, A. A.; Joshi, C. P.; Moharil, S. V.

    2016-05-01

    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 Pr3+, Gd3+,Gd3+-Eu3+, and Er3+-Tb3+ had been studied. Recently, a new quantum cutting phenomenon from visible photon shorter than 500 nm to two infrared photons for Tb3+-Yb3+, Pr3+-Yb3+, and Tm3+-Yb3+ has been reported. The Yb3+ ion is suitable as an acceptor and emitter because luminescent quantum efficiency of Yb3+ is close to 100% and the energy of the only excited level of Yb3+ (1.2 eV) is roughly in accordance with the band gap of Si (1.1 eV). In addition, the Ce3+-doped Tb3Al5O12 (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 Ce3+ ions in the TbAG can be suitable as an excellent sensitizing donor for down conversion materials of Si solar cells. In this

  10. BOREAS HYD-3 Subcanopy Incoming Solar Radiation Measurements

    NASA Technical Reports Server (NTRS)

    Hardy, Janet P.; Hall, Forrest G. (Editor); Knapp, David E. (Editor); Davis, Robert E.; Smith, David E. (Technical Monitor)

    2000-01-01

    The Boreal Ecosystem-Atmosphere Study (BOREAS) Hydrology (HYD)-3 team collected several data sets related to the hydrology of forested areas. This data set contains solar radiation measurements from several pyranometers (solar radiometers) placed on the snow surface in jack pine (1994) and black spruce and aspen forests (1996) in the BOREAS southern study area (SSA). An array of radiometers was used to collect data for three to four consecutive days in each forest type to study the hypothesis that energy transfer and snow water equivalent would vary spatially as a function of canopy closure. The quality of the data is good, because the days were generally clear and the radiometers were checked daily to remove anything that landed on the radiometers. The data are available in tabular ASCII files. The subcanopy incoming solar radiation measurement data are available from the Earth Observing System Data and Information System (EOSDIS) Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC). The data files are available on a CD-ROM (see document number 20010000884).

  11. Efficient near-infrared quantum cutting and downshift in Ce3+-Pr3+ codoped SrLaGa3S6O suitable for solar spectral converter

    NASA Astrophysics Data System (ADS)

    Zhang, Gongguo; Cui, Qiuyu; Liu, Guodong

    2016-03-01

    A novel solar spectral converter SrLaGa3S6O:Ce3+, Pr3+ for Si solar cells is developed. The luminescence spectra and the decay curves were investigated. The results show that through dual-mode NIR downconversions mechanism (quantum cutting and downshift), it can almost convert UV-blue-red (250-625 nm) photons into an intense NIR emission (930-1060 nm), perfectly matching the maximum spectral response of Si solar cells. The solar utilization of Si solar cell has been greatly broadening and enhancing. We believe this phosphor may open a new route for designing an advanced solar spectral converter for Si solar cells.

  12. The Solar Neighborhood. XXXVII: The Mass-Luminosity Relation for Main-sequence M Dwarfs

    NASA Astrophysics Data System (ADS)

    Benedict, G. F.; Henry, T. J.; Franz, O. G.; McArthur, B. E.; Wasserman, L. H.; Jao, Wei-Chun; Cargile, P. A.; Dieterich, S. B.; Bradley, A. J.; Nelan, E. P.; Whipple, A. L.

    2016-11-01

    We present a mass-luminosity relation (MLR) for red dwarfs spanning a range of masses from 0.62 {{ M }}⊙ to the end of the stellar main sequence at 0.08 {{ M }}⊙ . The relation is based on 47 stars for which dynamical masses have been determined, primarily using astrometric data from Fine Guidance Sensors (FGS) 3 and 1r, white-light interferometers on the Hubble Space Telescope (HST), and radial velocity data from McDonald Observatory. For our HST/FGS sample of 15 binaries, component mass errors range from 0.4% to 4.0% with a median error of 1.8%. With these and masses from other sources, we construct a V-band MLR for the lower main sequence with 47 stars and a K-band MLR with 45 stars with fit residuals half of those of the V band. We use GJ 831 AB as an example, obtaining an absolute trigonometric parallax, π abs = 125.3 ± 0.3 mas, with orbital elements yielding {{ M }}{{A}}=0.270+/- 0.004 {{ M }}⊙ and {{ M }}{{B}}=0.145+/- 0.002 {{ M }}⊙ . The mass precision rivals that derived for eclipsing binaries. A remaining major task is the interpretation of the intrinsic cosmic scatter in the observed MLR for low-mass stars in terms of physical effects. In the meantime, useful mass values can be estimated from the MLR for the ubiquitous red dwarfs that account for 75% of all stars, with applications ranging from the characterization of exoplanet host stars to the contribution of red dwarfs to the mass of the universe. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

  13. Er(3+)/Yb(3+) upconverters for InGaP solar cells under concentrated broadband illumination.

    PubMed

    Feenstra, J; Six, I F; Asselbergs, M A H; van Leest, R H; de Wild, J; Meijerink, A; Schropp, R E I; Rowan, A E; Schermer, J J

    2015-05-07

    The inability of solar cell materials to convert all incident photon energy into electrical current, provides a fundamental limit to the solar cell efficiency; the so called Shockley-Queisser (SQ) limit. A process termed upconversion provides a pathway to convert otherwise unabsorbed low energy photons passing through the solar cell into higher energy photons, which subsequently can be redirected back to the solar cell. The combination of a semi-transparent InGaP solar cell with lanthanide upconverters, consisting of ytterbium and erbium ions doped in three different host materials (Gd2O2S, Y2O3 and NaYF4) is investigated. Using sub-band gap light of wavelength range 890 nm to 1045 nm with a total accumulated power density of 2.7 kW m(-2), a distinct photocurrent was measured in the solar cell when the upconverters were applied whereas a zero current was measured without upconverter. Furthermore, a time delay between excitation and emission was observed for all upconverter systems which can be explained by energy transfer upconversion. Also, a quadratic dependence on the illumination intensity was observed for the NaYF4 and Y2O3 host material upconverters. The Gd2O2S host material upconverter deviated from the quadratic illumination intensity dependence towards linear behaviour, which can be attributed to saturation effects occurring at higher illumination power densities.

  14. Calculating Coronal Mass Ejection Magnetic Field at 1 AU Using Solar Observables

    NASA Astrophysics Data System (ADS)

    Chen, J.; Kunkel, V.

    2013-12-01

    It is well-established that most major nonrecurrent geomagnetic storms are caused by solar wind structures with long durations of strong southward (Bz < 0) interplanetary magnetic field (IMF). Such geoeffective IMF structures are associated with CME events at the Sun. Unfortunately, neither the duration nor the internal magnetic field vector of the ejecta--the key determinants of geoeffectiveness--is measurable until the observer (e.g., Earth) passes through the ejecta. In this paper, we discuss the quantitative relationships between the ejecta magnetic field at 1 AU and remotely observable solar quantities associated with the eruption of a given CME. In particular, we show that observed CME trajectories (position-time data) within, say, 1/3 AU of the Sun, contain sufficient information to allow the calculation of the ejecta magnetic field (magnitude and components) at 1 AU using the Erupting Flux Rope (EFR) model of CMEs. Furthermore, in order to accurately determine the size and arrival time of the ejecta as seen by a fixed observer at 1 AU (e.g., ACE), it is essential to accurately calculate the three-dimensional geometry of the underlying magnetic structure. Accordingly, we have extended the physics-based EFR model to include a self-consistent calculation of the transverse expansion taking into account the non-symmetric drag coupling between an expanding CME flux rope and the ambient solar wind. The dependence of the minor radius of the flux rope at 1 AU that determines the perceived size of the ejecta on solar quantities is discussed. Work supported by the NRL Base Program.

  15. Numerical simulations of the breakout model for the initiation of solar coronal mass ejections and in-situ observations of their interplanetary structure

    NASA Astrophysics Data System (ADS)

    Lynch, Benjamin James

    Coronal mass ejections (CMEs) are the one of the most exciting manifestations of dynamic solar activity and one of the most important solar inputs into the Sun-Earth system. Utilizing both large-scale numerical magnetohydrodynamics (MHD) simulations of solar eruptions and in-situ magnetic field and plasma measurements by satellites, substantial progress is made on a number of outstanding scientific questions about the origin, structure, and long-term heliospheric effects of CMEs. We present results of the first successful demonstration of the breakout model for CME initiation in 3-dimensions. The 3D topology allows for the gradual accumulation of free magnetic energy and magnetic reconnection external to the highly-sheared filament channel, which triggers catastrophic, runaway expansion and leads to the eruption of the low-lying sheared flux. Previous 2.5D breakout simulations are examined in an observational context. There is excellent agreement between the simulation results and CME morphology and dynamics through the corona, the properties of eruptive flare loop systems, and in the ejecta magnetic structure and in-situ measurements of the most coherent interplanetary CMEs. The magnetic and plasma structure of the most ordered interplanetary CMES (ICMEs, also called magnetic clouds) is examined using field and plasma data from the WIND and ACE spacecraft. We find anomalously high charge states of heavy ion species present, on average, throughout the entire magnetic cloud which suggests enhanced heating close to the sun, most-likely associated with eruptive flare magnetic reconnection. A long-term study of magnetic clouds events from 1995--2003 is also presented and the magnetic flux and helicity content is analyzed for solar-cycle trends. Magnetic clouds show a solar-cycle evolution of the preference for right-handed fields during the cycle 23 solar minimum that changes to a left-handed preference during solar maximum. A time varying dynamo-type source is present

  16. 3 Neutrino mass experiments fit a strange 3 + 3 model, but will KATRIN reveal the model's unique 3-part signature?

    NASA Astrophysics Data System (ADS)

    Ehrlich, R.

    2016-12-01

    Evidence is presented in support of an unconventional 3 + 3 model of the neutrino mass eigenstates with specific m2 > 0 and m2 < 0 masses. The two large m2 > 0 masses of the model were originally suggested based on a SN 1987A analysis, and they were further supported by several dark matter fits. The new evidence for one of the m2 > 0 mass values comes from an analysis of published data from the three most precise tritium β - decay experiments. The KATRIN experiment by virtue of a unique 3-part signature should either confirm or reject the model in its entirety.

  17. Sixteen Years of Ulysses Interstellar Dust Measurements in the Solar System. I. Mass Distribution and Gas-to-dust Mass Ratio

    NASA Astrophysics Data System (ADS)

    Krüger, Harald; Strub, Peter; Grün, Eberhard; Sterken, Veerle J.

    2015-10-01

    In the early 1990s, contemporary interstellar dust penetrating deep into the heliosphere was identified with the in situ dust detector on board the Ulysses spacecraft. Between 1992 and the end of 2007 Ulysses monitored the interstellar dust stream. The interstellar grains act as tracers of the physical conditions in the local interstellar medium (ISM) surrounding our solar system. Earlier analyses of the Ulysses interstellar dust data measured between 1992 and 1998 implied the existence of a population of “big” interstellar grains (up to 10-13 kg). The derived gas-to-dust-mass ratio was smaller than the one derived from astronomical observations, implying a concentration of interstellar dust in the very local ISM. In this paper we analyze the entire data set from 16 yr of Ulysses interstellar dust measurements in interplanetary space. This paper concentrates on the overall mass distribution of interstellar dust. An accompanying paper investigates time-variable phenomena in the Ulysses interstellar dust data, and in a third paper we present the results from dynamical modeling of the interstellar dust flow applied to Ulysses. We use the latest values for the interstellar hydrogen and helium densities, the interstellar helium flow speed of {v}{ISM∞ }=23.2 {km} {{{s}}}-1, and the ratio of radiation pressure to gravity, β, calculated for astronomical silicates. We find a gas-to-dust mass ratio in the local interstellar cloud of {R}{{g}/{{d}}}={193}-57+85, and a dust density of (2.1 ± 0.6) × 10-24 kg m-3. For a higher inflow speed of 26 {km} {{{s}}}-1, the gas-to-dust mass ratio is 20% higher, and, accordingly, the dust density is lower by the same amount. The gas-to-dust mass ratio derived from our new analysis is compatible with the value most recently determined from astronomical observations. We confirm earlier results that the very local ISM contains “big” (i.e., ≈1 μm sized) interstellar grains. We find a dust density in the local ISM that is a

  18. Mass and Energy of Erupting Solar Plasma Observed with the X-Ray Telescope on Hinode

    NASA Astrophysics Data System (ADS)

    Lee, Jin-Yi; Raymond, John C.; Reeves, Katharine K.; Moon, Yong-Jae; Kim, Kap-Sung

    2015-01-01

    We investigate seven eruptive plasma observations by Hinode/XRT. Their corresponding EUV and/or white light coronal mass ejection features are visible in some events. Five events are observed in several passbands in X-rays, which allows for the determination of the eruptive plasma temperature using a filter ratio method. We find that the isothermal temperatures vary from 1.6 to 10 MK. These temperatures are an average weighted toward higher temperature plasma. We determine the mass constraints of eruptive plasmas by assuming simplified geometrical structures of the plasma with isothermal plasma temperatures. This method provides an upper limit to the masses of the observed eruptive plasmas in X-ray passbands since any clumping causes the overestimation of the mass. For the other two events, we assume the temperatures are at the maximum temperature of the X-ray Telescope (XRT) temperature response function, which gives a lower limit of the masses. We find that the masses in XRT, ~3 × 1013-5 × 1014 g, are smaller in their upper limit than the total masses obtained by LASCO, ~1 × 1015 g. In addition, we estimate the radiative loss, thermal conduction, thermal, and kinetic energies of the eruptive plasma in X-rays. For four events, we find that the thermal conduction timescales are much shorter than the duration of eruption. This result implies that additional heating during the eruption may be required to explain the plasma observations in X-rays for the four events.

  19. Abundance of He-3 and other solar-wind-derived volatiles in lunar soil

    NASA Technical Reports Server (NTRS)

    Swindle, Timothy D.

    1992-01-01

    Volatiles implanted into the lunar regolith by the solar wind are potentially important lunar resources. Wittenberg et al. (1986) have proposed that lunar He-3 could be used as a fuel for terrestrial nuclear fusion reactors. They argue that a fusion scheme involving D and He-3 would be cleaner and more efficient than currently-proposed schemes involving D and T. However, since the terrestrial inventory of He-3 is so small, they suggest that the lunar regolith, with concentrations of the order of parts per billion (by mass) would be an economical source of He-3. Solar-wind implantation is also the primary source of H, C, and N in lunar soil. These elements could also be important, particularly for life support and for propellant production. In a SERC study of the feasibility of obtaining the necessary amount of He-3, Swindle et al. (1990) concluded that the available amount is sufficient for early reactors, at least, but that the mining problems, while not necessarily insurmountable, are prodigious. The volatiles H, C, and N, on the other hand, come in parts per million level abundances. The differences in abundances mean that (1) a comparable amount of H, C, and/or N could be extracted with orders of magnitude smaller operations than required for He-3, and (2) if He-3 extraction ever becomes important, huge quantities of H, C, and N will be produced as by-products.

  20. THE HELIOCENTRIC DISTANCE WHERE THE DEFLECTIONS AND ROTATIONS OF SOLAR CORONAL MASS EJECTIONS OCCUR

    SciTech Connect

    Kay, C.; Opher, M.

    2015-10-01

    Understanding the trajectory of a coronal mass ejection (CME), including any deflection from a radial path, and the orientation of its magnetic field is essential for space weather predictions. Kay et al. developed a model, Forecasting a CME’s Altered Trajectory (ForeCAT), of CME deflections and rotation due to magnetic forces, not including the effects of reconnection. ForeCAT is able to reproduce the deflection of observed CMEs. The deflecting CMEs tend to show a rapid increase of their angular momentum close to the Sun, followed by little to no increase at farther distances. Here we quantify the distance at which the CME deflection is “determined,” which we define as the distance after which the background solar wind has negligible influence on the total deflection. We consider a wide range in CME masses and radial speeds and determine that the deflection and rotation of these CMEs can be well-described by assuming they propagate with constant angular momentum beyond 10 R{sub ⊙}. The assumption of constant angular momentum beyond 10 R{sub ⊙} yields underestimates of the total deflection at 1 AU of only 1%–5% and underestimates of the rotation of 10%. Since the deflection from magnetic forces is determined by 10 R{sub ⊙}, non-magnetic forces must be responsible for any observed interplanetary deflections or rotations where the CME has increasing angular momentum.

  1. Binary Stars with Components of Solar Type: 25 Orbits and System Masses

    NASA Astrophysics Data System (ADS)

    Docobo, J. A.; Ling, J. F.

    2009-10-01

    Revised orbits and system masses are presented for the following 25 visual double stars: WDS 00593-0040 (A 1902), WDS 00596-0111 (A 1903 AB), WDS 01023+0552 (A 2003), WDS 01049+3649 (A 1515), WDS 01234+5809 (STF 115 AB), WDS 02399+0009 (A 1928), WDS 03310+2937 (A 983), WDS 06573-3530 (I 65), WDS 07043-0303 (A 519), WDS 08267+2432 (A 1746 BC), WDS 10585+1711 (A 2375), WDS 11308+4117 (STT 234), WDS 15370+6426 (HU 1168), WDS 16044-1122 (STF 1998 AB), WDS 16283-1613 (RST 3950), WDS 17324+2848 (A 352), WDS 18466+3821 (HU 1191), WDS 19039+2642 (A 2992), WDS 19055+3352(HU 940), WDS 19282-1209 (SCJ 22), WDS 19487+1504 (A 1658), WDS 22400+0113 (A 2099), WDS 23506-5142 (SLR 14), WDS 23518-0637 (A 2700), and WDS 23529-0309 (FIN 359). In all of these systems, at least one component is of solar type. Total system masses were calculated in each case from the orbital period and semiaxis major together with the Hipparcos parallax, except in the cases for which there are no Hipparcos data or when these values are not precise. Other orbital and physical properties of these stars are also discussed. This paper is the second of three collating the revised double star orbits we have calculated in the past 15 yr.

  2. Characterisation of a smartphone image sensor response to direct solar 305nm irradiation at high air masses.

    PubMed

    Igoe, D P; Amar, A; Parisi, A V; Turner, J

    2017-06-01

    This research reports the first time the sensitivity, properties and response of a smartphone image sensor that has been used to characterise the photobiologically important direct UVB solar irradiances at 305nm in clear sky conditions at high air masses. Solar images taken from Autumn to Spring were analysed using a custom Python script, written to develop and apply an adaptive threshold to mitigate the effects of both noise and hot-pixel aberrations in the images. The images were taken in an unobstructed area, observing from a solar zenith angle as high as 84° (air mass=9.6) to local solar maximum (up to a solar zenith angle of 23°) to fully develop the calibration model in temperatures that varied from 2°C to 24°C. The mean ozone thickness throughout all observations was 281±18 DU (to 2 standard deviations). A Langley Plot was used to confirm that there were constant atmospheric conditions throughout the observations. The quadratic calibration model developed has a strong correlation between the red colour channel from the smartphone with the Microtops measurements of the direct sun 305nm UV, with a coefficient of determination of 0.998 and very low standard errors. Validation of the model verified the robustness of the method and the model, with an average discrepancy of only 5% between smartphone derived and Microtops observed direct solar irradiances at 305nm. The results demonstrate the effectiveness of using the smartphone image sensor as a means to measure photobiologically important solar UVB radiation. The use of ubiquitous portable technologies, such as smartphones and laptop computers to perform data collection and analysis of solar UVB observations is an example of how scientific investigations can be performed by citizen science based individuals and groups, communities and schools.

  3. Clearance Analysis of Node 3 Aft CBM to the Stowed FGB Solar Array

    NASA Technical Reports Server (NTRS)

    Liddle, Donn

    2014-01-01

    measured within an accuracy of about 1 in. in each axis relative to the ISS Analysis Coordinate System (ISSACS). In October 2011, a proposed image-acquisition plan was drafted by ISAG and released for review. The ISS Robotics flight control team (ROBO) proposed minor changes to SPDM positions 1 and 4 to meet ISS proximity requirements. The updated image acquisition plan and draft chit were presented to and approved by the Systems Working Group (SWG) November 18 and were sent to the Vehicle Configuration Board (VCB) in early December 2011. Working with ROBO on 3 successive days (February 21, 22, and 23), ISAG collected 161 images of the ISS. Approximately 40 images were collected from each of the four different SSRMS/SPDM positions, with each set mapping the region from the Node 3 end cone, across Node 1, along the forward port side portion of the FGB, and out the port side FGB solar arrays. From this imagery, the best 80 images were selected for use in the analysis. The images were radiometrically enhanced to improve color and contrast and loaded into the FotoG analysis software along with the camera parameters and control data, which consisted of the coordinates for 54 handrail attachment bolts on the aft face of Node 3, in the ISSACS coordinate system. The results of this analysis produced the measured coordinates of 116 points distributed across the face of the FGB solar array panels (see figure 3) along with propagated uncertainty estimates in each coordinate axis. These results were sent to the ISS Vehicle Configuration Office, which sent them to the Configuration Analysis Modeling and Mass Properties (CAMMP) team for comparison with the Russian-provided CAD model for the retracted FGB solar arrays. The CAMMP analysis unexpectedly showed that the measured location of the port FGB solar array was up to 41-in. further outboard than the design and was slightly twisted about its rotational axis. The unexpected comparison results produced some initial concern regarding the

  4. Solar wind-magnetosphere coupling and the distant magnetotail - ISEE-3 observations

    NASA Technical Reports Server (NTRS)

    Slavin, J. A.; Smith, E. J.; Sibeck, D. G.; Baker, D. N.; Zwickl, R. D.; Akasofu, S.-I.; Lepping, R. P.

    1986-01-01

    ISEE-3 Geotail observations are used to investigate the relationship between the interplanetary magnetic field, substorm activity, and the distant magnetotail. Magnetic field and plasma observations are used to present evidence for the existence of a quasi-permanent, curved reconnection neutral line in the distant tail. The distance to the neutral line varies from absolute value of X = 120 to 140 R/sub e near the center of the tail to beyond absolute value of X = 200 R/sub e at the flanks. Downstream of the neutral line the plasma sheet magnetic field is shown to be negative and directly proportional to negative B/sub z in the solar wind as observed by IMP-8. V/sub x in the distant plasma sheet is also found to be proportional to IMF B/sub z with southward IMF producing the highest anti-solar flow velocities. A global dayside reconnection efficiency of 20 + or - 5 percent is derived from the ISEE-3/IMP-8 magnetic field comparisons. Substorm activity, as measured by the AL index, produces enhanced negative B/sub z and tailward V/sub x in the distant plasma sheet in agreement with the basic predictions of the reconnection-based models of substorms. The rate of magnetic flux transfer out of the tail as a function of AL is found to be consistent with previous near-earth studies. Similarly, the mass and energy fluxes carried by plasma sheet flow down the tail are consistent with theoretical mass and energy budgets for an open magnetosphere. In summary, the ISEE-3 Geotail observations appear to provide good support for reconnection models of solar wind-magnetosphere coupling and substorm energy rates.

  5. Solar wind-magnetosphere coupling and the distant magnetotail: ISEE-3 observations

    NASA Technical Reports Server (NTRS)

    Slavin, J. A.; Smith, E. J.; Sibeck, D. G.; Baker, D. N.; Zwickl, R. D.; Akasofu, S. I.; Lepping, R. P.

    1985-01-01

    ISEE-3 Geotail observations are used to investigate the relationship between the interplanetary magnetic field, substorm activity, and the distant magnetotail. Magnetic field and plasma observations are used to present evidence for the existence of a quasi-permanent, curved reconnection neutral line in the distant tail. The distance to the neutral line varies from absolute value of X = 120 to 140 R/sub e near the center of the tail to beyond absolute value of X = 200 R/sub e at the flanks. Downstream of the neutral line the plasma sheet magnetic field is shown to be negative and directly proportional to negative B/sub z in the solar wind as observed by IMP-8. V/sub x in the distant plasma sheet is also found to be proportional to IMF B/sub z with southward IMF producing the highest anti-solar flow velocities. A global dayside reconnection efficiency of 20 +- 5% is derived from the ISEE-3/IMP-8 magnetic field comparisons. Substorm activity, as measured by the AL index, produces enhanced negative B/sub z and tailward V/sub x in the distant plasma sheet in agreement with the basic predictions of the reconnection-based models of substorms. The rate of magnetic flux transfer out of the tail as a function of AL is found to be consistent with previous near-Earth studies. Similarly, the mass and energy fluxes carried by plasma sheet flow down the tail are consistent with theoretical mass and energy budgets for an open magnetosphere. In summary, the ISEE-3 Geotail observations appear to provide good support for reconnection models of solar wind-magnetosphere coupling and substorm energy rates.

  6. Influences of atmospheric conditions and air mass on the ratio of ultraviolet to total solar radiation

    SciTech Connect

    Riordan, C.J.; Hulstrom, R.L.; Myers, D.R.

    1990-08-01

    The technology to detoxify hazardous wastes using ultraviolet (UV) solar radiation is being investigated by the DOE/SERI Solar Thermal Technology Program. One of the elements of the technology evaluation is the assessment and characterization of UV solar radiation resources available for detoxification processes. This report describes the major atmospheric variables that determine the amount of UV solar radiation at the earth's surface, and how the ratio of UV-to-total solar radiation varies with atmospheric conditions. These ratios are calculated from broadband and spectral solar radiation measurements acquired at SERI, and obtained from the literature on modeled and measured UV solar radiation. The following sections discuss the atmospheric effects on UV solar radiation and provide UV-to-total solar radiation ratios from published studies, as well as measured values from SERI's data. A summary and conclusions are also given.

  7. Solar Physics

    NASA Technical Reports Server (NTRS)

    Wu, S. T.

    2000-01-01

    The areas of emphasis are: (1) develop theoretical models of the transient release of magnetic energy in the solar atmosphere, e.g., in solar flares, eruptive prominences, coronal mass ejections, etc.; (2) investigate the role of the Sun's magnetic field in the structuring of solar corona by the development of three-dimensional numerical models that describe the field configuration at various heights in the solar atmosphere by extrapolating the field at the photospheric level; (3) develop numerical models to investigate the physical parameters obtained by the ULYSSES mission; (4) develop numerical and theoretical models to investigate solar activity effects on the solar wind characteristics for the establishment of the solar-interplanetary transmission line; and (5) develop new instruments to measure solar magnetic fields and other features in the photosphere, chromosphere transition region and corona. We focused our investigation on the fundamental physical processes in solar atmosphere which directly effect our Planet Earth. The overall goal is to establish the physical process for the Sun-Earth connections.

  8. Low-mass gas envelopes around accreting cores embedded in radiative 3D discs

    NASA Astrophysics Data System (ADS)

    Lega, Elena; Lambrechts, Michiel

    2016-10-01

    Planets with a core mass larger than few Earth masses and a gaseous envelope not exceeding about 10% of the total mass budget are common. Such planets are present in the Solar System (Uranus, Neptune) and are frequently observed around other stars.Our knowledge about the evolution of gas envelopes is mainly based on 1D models. However, such models cannot investigate the complex interaction between the forming envelope and the surrounding gas disc.In this work we perform 3D hydrodynamics simulations accounting for energy transfer and radiative cooling using the FARGOCA code (Lega et al., MNRAS 440, 2014). In addition to the usually considered heatingsources, namely viscous and compressional heating, we have modeled the energy deposited by the accretion of solids.We show that the thermal evolution of the envelope of a 5 Earth mass core is mainly dominated by compressional heating for accretion rates lower than 5 Earth masses per 105 years.Additionally, we demonstrate efficient gas circulation through the envelope. Under certain conditions, the competition between gas circulation and cooling of the envelope can efficiently delay the onset of runaway accretion. This could help in explaining the population of planets with low-mass gas envelope.

  9. A grid of MHD models for stellar mass loss and spin-down rates of solar analogs

    SciTech Connect

    Cohen, O.; Drake, J. J.

    2014-03-01

    Stellar winds are believed to be the dominant factor in the spin-down of stars over time. However, stellar winds of solar analogs are poorly constrained due to observational challenges. In this paper, we present a grid of magnetohydrodynamic models to study and quantify the values of stellar mass loss and angular momentum loss rates as a function of the stellar rotation period, magnetic dipole component, and coronal base density. We derive simple scaling laws for the loss rates as a function of these parameters, and constrain the possible mass loss rate of stars with thermally driven winds. Despite the success of our scaling law in matching the results of the model, we find a deviation between the 'solar dipole' case and a real case based on solar observations that overestimates the actual solar mass loss rate by a factor of three. This implies that the model for stellar fields might require a further investigation with additional complexity. Mass loss rates in general are largely controlled by the magnetic field strength, with the wind density varying in proportion to the confining magnetic pressure B {sup 2}. We also find that the mass loss rates obtained using our grid models drop much faster with the increase in rotation period than scaling laws derived using observed stellar activity. For main-sequence solar-like stars, our scaling law for angular momentum loss versus poloidal magnetic field strength retrieves the well-known Skumanich decline of angular velocity with time, Ω{sub *}∝t {sup –1/2}, if the large-scale poloidal magnetic field scales with rotation rate as B{sub p}∝Ω{sub ⋆}{sup 2}.

  10. Efficient structures for geosynchronous spacecraft solar arrays. Phase 1, 2 and 3

    NASA Technical Reports Server (NTRS)

    Adams, L. R.; Hedgepeth, J. M.

    1981-01-01

    Structural concepts for deploying and supporting lightweight solar-array blankets for geosynchronous electrical power are evaluated. It is recommended that the STACBEAM solar-array system should be the object of further study and detailed evaluation. The STACBEAM system provides high stiffness at low mass, and with the use of a low mass deployment mechanism, full structural properties can be maintained throughout deployment. The stowed volume of the STACBEAM is acceptably small, and its linear deployment characteristic allows periodic attachments to the solar-array blanket to be established in the stowed configuration and maintained during deployment.

  11. Save With Solar, Fall 1998, Vol. 1, No. 3

    SciTech Connect

    Eiffert, P.

    1998-12-30

    This issue of Save with Solar highlights awards for federal renewable energy projects in FY 1998, the Million Solar Roofs Initiative, a special exhibition in New York City featuring solar technologies, PV systems working in Volcanoes National Park, and PV Super ESPC contracts.

  12. Do interacting coronal mass ejections play a role in solar energetic particle events?

    SciTech Connect

    Kahler, S. W.; Vourlidas, A.

    2014-03-20

    Gradual solar energetic (E > 10 MeV) particle (SEP) events are produced in shocks driven by fast and wide coronal mass ejections (CMEs). With a set of western hemisphere 20 MeV SEP events, we test the possibility that SEP peak intensities, Ip, are enhanced by interactions of their associated CMEs with preceding CMEs (preCMEs) launched during the previous 12 hr. Among SEP events with no, 1, or 2 or more (2+) preCMEs, we find enhanced Ip for the groups with preCMEs, but no differences in TO+TR, the time from CME launch to SEP onset and the time from onset to SEP half-peak Ip. Neither the timings of the preCMEs relative to their associated CMEs nor the preCME widths W {sub pre}, speeds V {sub pre}, or numbers correlate with the SEP Ip values. The 20 MeV Ip of all the preCME groups correlate with the 2 MeV proton background intensities, consistent with a general correlation with possible seed particle populations. Furthermore, the fraction of CMEs with preCMEs also increases with the 2 MeV proton background intensities. This implies that the higher SEP Ip values with preCMEs may not be due primarily to CME interactions, such as the 'twin-CME' scenario, but are explained by a general increase of both background seed particles and more frequent CMEs during times of higher solar activity. This explanation is not supported by our analysis of 2 MeV proton backgrounds in two earlier preCME studies of SEP events, so the relevance of CME interactions for larger SEP event intensities remains unclear.

  13. A comparison of solar energetic particle event timescales with properties of associated coronal mass ejections

    SciTech Connect

    Kahler, S. W.

    2013-06-01

    The dependence of solar energetic proton (SEP) event peak intensities Ip on properties of associated coronal mass ejections (CMEs) has been extensively examined, but the dependence of SEP event timescales is not well known. We define three timescales of 20 MeV SEP events and ask how they are related to speeds v {sub CME} or widths W of their associated CMEs observed by LASCO/SOHO. The timescales of the EPACT/Wind 20 MeV events are TO, the onset time from CME launch to SEP onset; TR, the rise time from onset to half the peak intensity (0.5Ip); and TD, the duration of the SEP intensity above 0.5Ip. This is a statistical study based on 217 SEP-CME events observed during 1996-2008. The large number of SEP events allows us to examine the SEP-CME relationship in five solar-source longitude ranges. In general, we statistically find that TO declines slightly with v {sub CME}, and TR and TD increase with both v {sub CME} and W. TO is inversely correlated with log Ip, as expected from a particle background effect. We discuss the implications of this result and find that a background-independent parameter TO+TR also increases with v {sub CME} and W. The correlations generally fall below the 98% significance level, but there is a significant correlation between v {sub CME} and W which renders interpretation of the timescale results uncertain. We suggest that faster (and wider) CMEs drive shocks and accelerate SEPs over longer times to produce the longer TR and TD SEP timescales.

  14. A Comparison of Solar Energetic Particle Event Timescales with Properties of Associated Coronal Mass Ejections

    NASA Astrophysics Data System (ADS)

    Kahler, S. W.

    2013-06-01

    The dependence of solar energetic proton (SEP) event peak intensities Ip on properties of associated coronal mass ejections (CMEs) has been extensively examined, but the dependence of SEP event timescales is not well known. We define three timescales of 20 MeV SEP events and ask how they are related to speeds v CME or widths W of their associated CMEs observed by LASCO/SOHO. The timescales of the EPACT/Wind 20 MeV events are TO, the onset time from CME launch to SEP onset; TR, the rise time from onset to half the peak intensity (0.5Ip); and TD, the duration of the SEP intensity above 0.5Ip. This is a statistical study based on 217 SEP-CME events observed during 1996-2008. The large number of SEP events allows us to examine the SEP-CME relationship in five solar-source longitude ranges. In general, we statistically find that TO declines slightly with v CME, and TR and TD increase with both v CME and W. TO is inversely correlated with log Ip, as expected from a particle background effect. We discuss the implications of this result and find that a background-independent parameter TO+TR also increases with v CME and W. The correlations generally fall below the 98% significance level, but there is a significant correlation between v CME and W which renders interpretation of the timescale results uncertain. We suggest that faster (and wider) CMEs drive shocks and accelerate SEPs over longer times to produce the longer TR and TD SEP timescales.

  15. Do Interacting Coronal Mass Ejections Play a Role in Solar Energetic Particle Events?

    NASA Astrophysics Data System (ADS)

    Kahler, S. W.; Vourlidas, A.

    2014-03-01

    Gradual solar energetic (E > 10 MeV) particle (SEP) events are produced in shocks driven by fast and wide coronal mass ejections (CMEs). With a set of western hemisphere 20 MeV SEP events, we test the possibility that SEP peak intensities, Ip, are enhanced by interactions of their associated CMEs with preceding CMEs (preCMEs) launched during the previous 12 hr. Among SEP events with no, 1, or 2 or more (2+) preCMEs, we find enhanced Ip for the groups with preCMEs, but no differences in TO+TR, the time from CME launch to SEP onset and the time from onset to SEP half-peak Ip. Neither the timings of the preCMEs relative to their associated CMEs nor the preCME widths W pre, speeds V pre, or numbers correlate with the SEP Ip values. The 20 MeV Ip of all the preCME groups correlate with the 2 MeV proton background intensities, consistent with a general correlation with possible seed particle populations. Furthermore, the fraction of CMEs with preCMEs also increases with the 2 MeV proton background intensities. This implies that the higher SEP Ip values with preCMEs may not be due primarily to CME interactions, such as the "twin-CME" scenario, but are explained by a general increase of both background seed particles and more frequent CMEs during times of higher solar activity. This explanation is not supported by our analysis of 2 MeV proton backgrounds in two earlier preCME studies of SEP events, so the relevance of CME interactions for larger SEP event intensities remains unclear.

  16. Surface Properties of CH3NH3PbI3 for Perovskite Solar Cells.

    PubMed

    Haruyama, Jun; Sodeyama, Keitaro; Han, Liyuan; Tateyama, Yoshitaka

    2016-03-15

    Perovskite solar cells (PSCs) have attracted considerable interest because of their high potential for solar energy conversion. Power conversion efficiencies of the PSCs have rapidly increased from 3.8 to over 20% only in the past few years. PSCs have several similarities to dye-sensitized solar cells in their device compositions; mesoporous TiO2 (mp-TiO2) is sensitized by light-absorbing components and placed into a medium containing hole transporting materials (HTMs). On the other hand, the perovskite materials for the light-harvesting, for example, CH3NH3PbI3 (MAPbI3), have a greater advantage for the photovoltaic applications; extremely long photocarrier diffusion lengths (over 1 μm) enable carrier transports without singnificant loss. In this respect, the surface states, that can be possible recombination centers, are also of great importance. Availability of solution processes is another important aspect in terms of low cost fabrication of PSCs. Two-step methods, where PbI2 is first introduced from solution onto a mp-TiO2 film and subsequently transformed into the MAPbI3 by the exposition of a solution containing MAI, suggest that use of such a high PbI2 concentration is crucial to obtain higher performance. The experiments also indicate that the PbI2-rich growth condition modifies TiO2/ or HTM/MAPbI3 interfaces in such a way that the photocarrier transport is improved. Thus, the characteristics of surfaces and interfaces play key roles in the high efficiencies of the PSCs. In this Account, we focus on the structural stability and electronic states of the representative (110), (001), (100), and (101) surfaces of tetragonal MAPbI3, which can be regarded as reasonable model HTM/MAPbI3 interfaces, by use of first-principles calculations. By examining various types of PbIx polyhedron terminations, we found that there are two major phases on all of the four surface facets. They can be classified as vacant- and flat-type terminations, and the former is more stable

  17. Applications of thin film technology toward a low-mass solar power satellite

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.; Cull, Ronald C.

    1990-01-01

    Previous concepts for solar power satellites have used conventional-technology photovoltaics and microwave tubes. The authors propose using thin film photovoltaics and an integrated solid state phased array to design an ultra-lightweight solar power satellite, resulting in a potential reduction in weight by a factor of ten to a hundred over conventional concepts for solar power satellites.

  18. Solar technology assessment project. Volume 3: Active space heating and hot water supply with solar energy

    NASA Astrophysics Data System (ADS)

    Karaki, S.; Loef, G. O. G.

    1981-04-01

    Several types of solar water heaters are described and assessed. These include thermosiphon water heaters and pump circulation water heaters. Auxiliary water heating is briefly discussed, and new and retrofit systems are compared. Liquid-based space heating systems and solar air heaters are described and assessed, auxiliary space heating are discussed, and new and retrofit solar space heating systems are compared. The status of flat plate collectors, evacuated tube collectors, and thermal storage systems is examined. Systems improvements, reliability, durability and maintenance are discussed. The economic assessment of space and water heating systems includes a comparison of new systems costs with conventional fuels, and sales history and projections. The variety of participants in the solar industry and users of solar heat is discussed, and various incentives and barriers to solar heating are examined. Several policy implications are discussed, and specific government actions are recommended.

  19. Effect of Morphology Control of Light Absorbing Layer on CH3NH3PbI3 Perovskite Solar Cells.

    PubMed

    Lei, Binglong; Eze, Vincent Obiozo; Mori, Tatsuo

    2016-04-01

    As one of the most significant components of perovskite solar cells, the perovskite light absorbing layer demands high quality to guarantee extraordinary power conversion efficiency (PCE). We have fabricated series of CH3NH3PbI3 perovskite solar cells by virtue of gas-flowing assisting (GFA), spin coating twice for the Pbl2 layer and dipping the semi-samples in a thermal CH3NH3I solution, by which some undesirable perovskite morphologies can be effectively avoided. The modified conductions have also dramatically improved the perovskite layer and elevated the coverage ratio from 53.6% to 79.5%. All the fabrication processes, except the steps for deposition of the hole transport material (HTM) and back gold electrode, have been conducted in air and an average PCE of 6.6% has been achieved by initiatively applying N,N'-bis(1-naphtyl)-N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine (α-NPD) doped by MoO3 as HTM. The CH3NH3PbI3 perovskite's morphology and its coverage ratio to the underneath TiO2 mesoporic layer are evaluated to account for the cells' performance. It has demonstrated that higher homogeneity and coverage ratio of the CH3NH3PbI3 layer have most significantly contributed to the solar cells' light conversion efficiency. Keywords: Perovskite, Solar Cell, Morphology, Coverage Ratio, Hole Transport Material.

  20. GW151226: Observation of Gravitational Waves from a 22-Solar-Mass Binary Black Hole Coalescence

    NASA Astrophysics Data System (ADS)

    Abbott, B. P.; Abbott, R.; Abbott, T. D.; Abernathy, M. R.; Acernese, F.; Ackley, K.; Adams, C.; Adams, T.; Addesso, P.; Adhikari, R. X.; Adya, V. B.; Affeldt, C.; Agathos, M.; Agatsuma, K.; Aggarwal, N.; Aguiar, O. D.; Aiello, L.; Ain, A.; Ajith, P.; Allen, B.; Allocca, A.; Altin, P. A.; Anderson, S. B.; Anderson, W. G.; Arai, K.; Araya, M. C.; Arceneaux, C. C.; Areeda, J. S.; Arnaud, N.; Arun, K. G.; Ascenzi, S.; Ashton, G.; Ast, M.; Aston, S. M.; Astone, P.; Aufmuth, P.; Aulbert, C.; Babak, S.; Bacon, P.; Bader, M. K. M.; Baker, P. T.; Baldaccini, F.; Ballardin, G.; Ballmer, S. W.; Barayoga, J. C.; Barclay, S. E.; Barish, B. C.; Barker, D.; Barone, F.; Barr, B.; Barsotti, L.; Barsuglia, M.; Barta, D.; Bartlett, J.; Bartos, I.; Bassiri, R.; Basti, A.; Batch, J. C.; Baune, C.; Bavigadda, V.; Bazzan, M.; Bejger, M.; Bell, A. S.; Berger, B. K.; Bergmann, G.; Berry, C. P. L.; Bersanetti, D.; Bertolini, A.; Betzwieser, J.; Bhagwat, S.; Bhandare, R.; Bilenko, I. A.; Billingsley, G.; Birch, J.; Birney, R.; Birnholtz, O.; Biscans, S.; Bisht, A.; Bitossi, M.; Biwer, C.; Bizouard, M. A.; Blackburn, J. K.; Blair, C. D.; Blair, D. G.; Blair, R. M.; Bloemen, S.; Bock, O.; Boer, M.; Bogaert, G.; Bogan, C.; Bohe, A.; Bond, C.; Bondu, F.; Bonnand, R.; Boom, B. A.; Bork, R.; Boschi, V.; Bose, S.; Bouffanais, Y.; Bozzi, A.; Bradaschia, C.; Brady, P. R.; Braginsky, V. B.; Branchesi, M.; Brau, J. E.; Briant, T.; Brillet, A.; Brinkmann, M.; Brisson, V.; Brockill, P.; Broida, J. E.; Brooks, A. F.; Brown, D. A.; Brown, D. D.; Brown, N. M.; Brunett, S.; Buchanan, C. C.; Buikema, A.; Bulik, T.; Bulten, H. J.; Buonanno, A.; Buskulic, D.; Buy, C.; Byer, R. L.; Cabero, M.; Cadonati, L.; Cagnoli, G.; Cahillane, C.; Calderón Bustillo, J.; Callister, T.; Calloni, E.; Camp, J. B.; Cannon, K. C.; Cao, J.; Capano, C. D.; Capocasa, E.; Carbognani, F.; Caride, S.; Casanueva Diaz, J.; Casentini, C.; Caudill, S.; Cavaglià, M.; Cavalier, F.; Cavalieri, R.; Cella, G.; Cepeda, C. B.; Cerboni Baiardi, L.; Cerretani, G.; Cesarini, E.; Chamberlin, S. J.; Chan, M.; Chao, S.; Charlton, P.; Chassande-Mottin, E.; Cheeseboro, B. D.; Chen, H. Y.; Chen, Y.; Cheng, C.; Chincarini, A.; Chiummo, A.; Cho, H. S.; Cho, M.; Chow, J. H.; Christensen, N.; Chu, Q.; Chua, S.; Chung, S.; Ciani, G.; Clara, F.; Clark, J. A.; Cleva, F.; Coccia, E.; Cohadon, P.-F.; Colla, A.; Collette, C. G.; Cominsky, L.; Constancio, M.; Conte, A.; Conti, L.; Cook, D.; Corbitt, T. R.; Cornish, N.; Corsi, A.; Cortese, S.; Costa, C. A.; Coughlin, M. W.; Coughlin, S. B.; Coulon, J.-P.; Countryman, S. T.; Couvares, P.; Cowan, E. E.; Coward, D. M.; Cowart, M. J.; Coyne, D. C.; Coyne, R.; Craig, K.; Creighton, J. D. E.; Cripe, J.; Crowder, S. G.; Cumming, A.; Cunningham, L.; Cuoco, E.; Dal Canton, T.; Danilishin, S. L.; D'Antonio, S.; Danzmann, K.; Darman, N. S.; Dasgupta, A.; Da Silva Costa, C. F.; Dattilo, V.; Dave, I.; Davier, M.; Davies, G. S.; Daw, E. J.; Day, R.; De, S.; DeBra, D.; Debreczeni, G.; Degallaix, J.; De Laurentis, M.; Deléglise, S.; Del Pozzo, W.; Denker, T.; Dent, T.; Dergachev, V.; De Rosa, R.; DeRosa, R. T.; DeSalvo, R.; Devine, R. C.; Dhurandhar, S.; Díaz, M. C.; Di Fiore, L.; Di Giovanni, M.; Di Girolamo, T.; Di Lieto, A.; Di Pace, S.; Di Palma, I.; Di Virgilio, A.; Dolique, V.; Donovan, F.; Dooley, K. L.; Doravari, S.; Douglas, R.; Downes, T. P.; Drago, M.; Drever, R. W. P.; Driggers, J. C.; Ducrot, M.; Dwyer, S. E.; Edo, T. B.; Edwards, M. C.; Effler, A.; Eggenstein, H.-B.; Ehrens, P.; Eichholz, J.; Eikenberry, S. S.; Engels, W.; Essick, R. C.; Etzel, T.; Evans, M.; Evans, T. M.; Everett, R.; Factourovich, M.; Fafone, V.; Fair, H.; Fairhurst, S.; Fan, X.; Fang, Q.; Farinon, S.; Farr, B.; Farr, W. M.; Favata, M.; Fays, M.; Fehrmann, H.; Fejer, M. M.; Fenyvesi, E.; Ferrante, I.; Ferreira, E. C.; Ferrini, F.; Fidecaro, F.; Fiori, I.; Fiorucci, D.; Fisher, R. P.; Flaminio, R.; Fletcher, M.; Fong, H.; Fournier, J.-D.; Frasca, S.; Frasconi, F.; Frei, Z.; Freise, A.; Frey, R.; Frey, V.; Fritschel, P.; Frolov, V. V.; Fulda, P.; Fyffe, M.; Gabbard, H. A. G.; Gair, J. R.; Gammaitoni, L.; Gaonkar, S. G.; Garufi, F.; Gaur, G.; Gehrels, N.; Gemme, G.; Geng, P.; Genin, E.; Gennai, A.; George, J.; Gergely, L.; Germain, V.; Ghosh, Abhirup; Ghosh, Archisman; Ghosh, S.; Giaime, J. A.; Giardina, K. D.; Giazotto, A.; Gill, K.; Glaefke, A.; Goetz, E.; Goetz, R.; Gondan, L.; González, G.; Gonzalez Castro, J. M.; Gopakumar, A.; Gordon, N. A.; Gorodetsky, M. L.; Gossan, S. E.; Gosselin, M.; Gouaty, R.; Grado, A.; Graef, C.; Graff, P. B.; Granata, M.; Grant, A.; Gras, S.; Gray, C.; Greco, G.; Green, A. C.; Groot, P.; Grote, H.; Grunewald, S.; Guidi, G. M.; Guo, X.; Gupta, A.; Gupta, M. K.; Gushwa, K. E.; Gustafson, E. K.; Gustafson, R.; Hacker, J. J.; Hall, B. R.; Hall, E. D.; Hamilton, H.; Hammond, G.; Haney, M.; Hanke, M. M.; Hanks, J.; Hanna, C.; Hannam, M. D.; Hanson, J.; Hardwick, T.; Harms, J.; Harry, G. M.; Harry, I. W.; Hart, M. J.; Hartman, M. T.; Haster, C.-J.; Haughian, K.; Healy, J.; Heidmann, A.; Heintze, M. C.; Heitmann, H.; Hello, P.; Hemming, G.; Hendry, M.; Heng, I. S.; Hennig, J.; Henry, J.; Heptonstall, A. W.; Heurs, M.; Hild, S.; Hoak, D.; Hofman, D.; Holt, K.; Holz, D. E.; Hopkins, P.; Hough, J.; Houston, E. A.; Howell, E. J.; Hu, Y. M.; Huang, S.; Huerta, E. A.; Huet, D.; Hughey, B.; Husa, S.; Huttner, S. H.; Huynh-Dinh, T.; Indik, N.; Ingram, D. R.; Inta, R.; Isa, H. N.; Isac, J.-M.; Isi, M.; Isogai, T.; Iyer, B. R.; Izumi, K.; Jacqmin, T.; Jang, H.; Jani, K.; Jaranowski, P.; Jawahar, S.; Jian, L.; Jiménez-Forteza, F.; Johnson, W. W.; Johnson-McDaniel, N. K.; Jones, D. I.; Jones, R.; Jonker, R. J. G.; Ju, L.; K, Haris; Kalaghatgi, C. V.; Kalogera, V.; Kandhasamy, S.; Kang, G.; Kanner, J. B.; Kapadia, S. J.; Karki, S.; Karvinen, K. S.; Kasprzack, M.; Katsavounidis, E.; Katzman, W.; Kaufer, S.; Kaur, T.; Kawabe, K.; Kéfélian, F.; Kehl, M. S.; Keitel, D.; Kelley, D. B.; Kells, W.; Kennedy, R.; Key, J. S.; Khalili, F. Y.; Khan, I.; Khan, S.; Khan, Z.; Khazanov, E. A.; Kijbunchoo, N.; Kim, Chi-Woong; Kim, Chunglee; Kim, J.; Kim, K.; Kim, N.; Kim, W.; Kim, Y.-M.; Kimbrell, S. J.; King, E. J.; King, P. J.; Kissel, J. S.; Klein, B.; Kleybolte, L.; Klimenko, S.; Koehlenbeck, S. M.; Koley, S.; Kondrashov, V.; Kontos, A.; Korobko, M.; Korth, W. Z.; Kowalska, I.; Kozak, D. B.; Kringel, V.; Krishnan, B.; Królak, A.; Krueger, C.; Kuehn, G.; Kumar, P.; Kumar, R.; Kuo, L.; Kutynia, A.; Lackey, B. D.; Landry, M.; Lange, J.; Lantz, B.; Lasky, P. D.; Laxen, M.; Lazzarini, A.; Lazzaro, C.; Leaci, P.; Leavey, S.; Lebigot, E. O.; Lee, C. H.; Lee, H. K.; Lee, H. M.; Lee, K.; Lenon, A.; Leonardi, M.; Leong, J. R.; Leroy, N.; Letendre, N.; Levin, Y.; Lewis, J. B.; Li, T. G. F.; Libson, A.; Littenberg, T. B.; Lockerbie, N. A.; Lombardi, A. L.; London, L. T.; Lord, J. E.; Lorenzini, M.; Loriette, V.; Lormand, M.; Losurdo, G.; Lough, J. D.; Lousto, C. O.; Lück, H.; Lundgren, A. P.; Lynch, R.; Ma, Y.; Machenschalk, B.; MacInnis, M.; Macleod, D. M.; Magaña-Sandoval, F.; Magaña Zertuche, L.; Magee, R. M.; Majorana, E.; Maksimovic, I.; Malvezzi, V.; Man, N.; Mandel, I.; Mandic, V.; Mangano, V.; Mansell, G. L.; Manske, M.; Mantovani, M.; Marchesoni, F.; Marion, F.; Márka, S.; Márka, Z.; Markosyan, A. S.; Maros, E.; Martelli, F.; Martellini, L.; Martin, I. W.; Martynov, D. V.; Marx, J. N.; Mason, K.; Masserot, A.; Massinger, T. J.; Masso-Reid, M.; Mastrogiovanni, S.; Matichard, F.; Matone, L.; Mavalvala, N.; Mazumder, N.; McCarthy, R.; McClelland, D. E.; McCormick, S.; McGuire, S. C.; McIntyre, G.; McIver, J.; McManus, D. J.; McRae, T.; McWilliams, S. T.; Meacher, D.; Meadors, G. D.; Meidam, J.; Melatos, A.; Mendell, G.; Mercer, R. A.; Merilh, E. L.; Merzougui, M.; Meshkov, S.; Messenger, C.; Messick, C.; Metzdorff, R.; Meyers, P. M.; Mezzani, F.; Miao, H.; Michel, C.; Middleton, H.; Mikhailov, E. E.; Milano, L.; Miller, A. L.; Miller, A.; Miller, B. B.; Miller, J.; Millhouse, M.; Minenkov, Y.; Ming, J.; Mirshekari, S.; Mishra, C.; Mitra, S.; Mitrofanov, V. P.; Mitselmakher, G.; Mittleman, R.; Moggi, A.; Mohan, M.; Mohapatra, S. R. P.; Montani, M.; Moore, B. C.; Moore, C. J.; Moraru, D.; Moreno, G.; Morriss, S. R.; Mossavi, K.; Mours, B.; Mow-Lowry, C. M.; Mueller, G.; Muir, A. W.; Mukherjee, Arunava; Mukherjee, D.; Mukherjee, S.; Mukund, N.; Mullavey, A.; Munch, J.; Murphy, D. J.; Murray, P. G.; Mytidis, A.; Nardecchia, I.; Naticchioni, L.; Nayak, R. K.; Nedkova, K.; Nelemans, G.; Nelson, T. J. N.; Neri, M.; Neunzert, A.; Newton, G.; Nguyen, T. T.; Nielsen, A. B.; Nissanke, S.; Nitz, A.; Nocera, F.; Nolting, D.; Normandin, M. E. N.; Nuttall, L. K.; Oberling, J.; Ochsner, E.; O'Dell, J.; Oelker, E.; Ogin, G. H.; Oh, J. J.; Oh, S. H.; Ohme, F.; Oliver, M.; Oppermann, P.; Oram, Richard J.; O'Reilly, B.; O'Shaughnessy, R.; Ottaway, D. J.; Overmier, H.; Owen, B. J.; Pai, A.; Pai, S. A.; Palamos, J. R.; Palashov, O.; Palomba, C.; Pal-Singh, A.; Pan, H.; Pankow, C.; Pannarale, F.; Pant, B. C.; Paoletti, F.; Paoli, A.; Papa, M. A.; Paris, H. R.; Parker, W.; Pascucci, D.; Pasqualetti, A.; Passaquieti, R.; Passuello, D.; Patricelli, B.; Patrick, Z.; Pearlstone, B. L.; Pedraza, M.; Pedurand, R.; Pekowsky, L.; Pele, A.; Penn, S.; Perreca, A.; Perri, L. M.; Pfeiffer, H. P.; Phelps, M.; Piccinni, O. J.; Pichot, M.; Piergiovanni, F.; Pierro, V.; Pillant, G.; Pinard, L.; Pinto, I. M.; Pitkin, M.; Poe, M.; Poggiani, R.; Popolizio, P.; Post, A.; Powell, J.; Prasad, J.; Predoi, V.; Prestegard, T.; Price, L. R.; Prijatelj, M.; Principe, M.; Privitera, S.; Prix, R.; Prodi, G. A.; Prokhorov, L.; Puncken, O.; Punturo, M.; Puppo, P.; Pürrer, M.; Qi, H.; Qin, J.; Qiu, S.; Quetschke, V.; Quintero, E. A.; Quitzow-James, R.; Raab, F. J.; Rabeling, D. S.; Radkins, H.; Raffai, P.; Raja, S.; Rajan, C.; Rakhmanov, M.; Rapagnani, P.; Raymond, V.; Razzano, M.; Re, V.; Read, J.; Reed, C. M.; Regimbau, T.; Rei, L.; Reid, S.; Reitze, D. H.; Rew, H.; Reyes, S. D.; Ricci, F.; Riles, K.; Rizzo, M.; Robertson, N. A.; Robie, R.; Robinet, F.; Rocchi, A.; Rolland, L.; Rollins, J. G.; Roma, V. J.; Romano, J. D.; Romano, R.; Romanov, G.; Romie, J. H.; Rosińska, D.; Rowan, S.; Rüdiger, A.; Ruggi, P.; Ryan, K.; Sachdev, S.; Sadecki, T.; Sadeghian, L.; Sakellariadou, M.; Salconi, L.; Saleem, M.; Salemi, F.; Samajdar, A.; Sammut, L.; Sanchez, E. J.; Sandberg, V.; Sandeen, B.; Sanders, J. R.; Sassolas, B.; Sathyaprakash, B. S.; Saulson, P. R.; Sauter, O. E. S.; Savage, R. L.; Sawadsky, A.; Schale, P.; Schilling, R.; Schmidt, J.; Schmidt, P.; Schnabel, R.; Schofield, R. M. S.; Schönbeck, A.; Schreiber, E.; Schuette, D.; Schutz, B. F.; Scott, J.; Scott, S. M.; Sellers, D.; Sengupta, A. S.; Sentenac, D.; Sequino, V.; Sergeev, A.; Setyawati, Y.; Shaddock, D. A.; Shaffer, T.; Shahriar, M. S.; Shaltev, M.; Shapiro, B.; Shawhan, P.; Sheperd, A.; Shoemaker, D. H.; Shoemaker, D. M.; Siellez, K.; Siemens, X.; Sieniawska, M.; Sigg, D.; Silva, A. D.; Singer, A.; Singer, L. P.; Singh, A.; Singh, R.; Singhal, A.; Sintes, A. M.; Slagmolen, B. J. J.; Smith, J. R.; Smith, N. D.; Smith, R. J. E.; Son, E. J.; Sorazu, B.; Sorrentino, F.; Souradeep, T.; Srivastava, A. K.; Staley, A.; Steinke, M.; Steinlechner, J.; Steinlechner, S.; Steinmeyer, D.; Stephens, B. C.; Stevenson, S. P.; Stone, R.; Strain, K. A.; Straniero, N.; Stratta, G.; Strauss, N. A.; Strigin, S.; Sturani, R.; Stuver, A. L.; Summerscales, T. Z.; Sun, L.; Sunil, S.; Sutton, P. J.; Swinkels, B. L.; Szczepańczyk, M. J.; Tacca, M.; Talukder, D.; Tanner, D. B.; Tápai, M.; Tarabrin, S. P.; Taracchini, A.; Taylor, R.; Theeg, T.; Thirugnanasambandam, M. P.; Thomas, E. G.; Thomas, M.; Thomas, P.; Thorne, K. A.; Thrane, E.; Tiwari, S.; Tiwari, V.; Tokmakov, K. V.; Toland, K.; Tomlinson, C.; Tonelli, M.; Tornasi, Z.; Torres, C. V.; Torrie, C. I.; Töyrä, D.; Travasso, F.; Traylor, G.; Trifirò, D.; Tringali, M. C.; Trozzo, L.; Tse, M.; Turconi, M.; Tuyenbayev, D.; Ugolini, D.; Unnikrishnan, C. S.; Urban, A. L.; Usman, S. A.; Vahlbruch, H.; Vajente, G.; Valdes, G.; Vallisneri, M.; van Bakel, N.; van Beuzekom, M.; van den Brand, J. F. J.; Van Den Broeck, C.; Vander-Hyde, D. C.; van der Schaaf, L.; van Heijningen, J. V.; van Veggel, A. A.; Vardaro, M.; Vass, S.; Vasúth, M.; Vaulin, R.; Vecchio, A.; Vedovato, G.; Veitch, J.; Veitch, P. J.; Venkateswara, K.; Verkindt, D.; Vetrano, F.; Viceré, A.; Vinciguerra, S.; Vine, D. J.; Vinet, J.-Y.; Vitale, S.; Vo, T.; Vocca, H.; Vorvick, C.; Voss, D. V.; Vousden, W. D.; Vyatchanin, S. P.; Wade, A. R.; Wade, L. E.; Wade, M.; Walker, M.; Wallace, L.; Walsh, S.; Wang, G.; Wang, H.; Wang, M.; Wang, X.; Wang, Y.; Ward, R. L.; Warner, J.; Was, M.; Weaver, B.; Wei, L.-W.; Weinert, M.; Weinstein, A. J.; Weiss, R.; Wen, L.; Weßels, P.; Westphal, T.; Wette, K.; Whelan, J. T.; Whiting, B. F.; Williams, R. D.; Williamson, A. R.; Willis, J. L.; Willke, B.; Wimmer, M. H.; Winkler, W.; Wipf, C. C.; Wittel, H.; Woan, G.; Woehler, J.; Worden, J.; Wright, J. L.; Wu, D. S.; Wu, G.; Yablon, J.; Yam, W.; Yamamoto, H.; Yancey, C. C.; Yu, H.; Yvert, M.; ZadroŻny, A.; Zangrando, L.; Zanolin, M.; Zendri, J.-P.; Zevin, M.; Zhang, L.; Zhang, M.; Zhang, Y.; Zhao, C.; Zhou, M.; Zhou, Z.; Zhu, X. J.; Zucker, M. E.; Zuraw, S. E.; Zweizig, J.; Boyle, M.; Hemberger, D.; Kidder, L. E.; Lovelace, G.; Ossokine, S.; Scheel, M.; Szilagyi, B.; Teukolsky, S.; LIGO Scientific Collaboration; Virgo Collaboration

    2016-06-01

    We report the observation of a gravitational-wave signal produced by the coalescence of two stellar-mass black holes. The signal, GW151226, was observed by the twin detectors of the Laser Interferometer Gravitational-Wave Observatory (LIGO) on December 26, 2015 at 03:38:53 UTC. The signal was initially identified within 70 s by an online matched-filter search targeting binary coalescences. Subsequent off-line analyses recovered GW151226 with a network signal-to-noise ratio of 13 and a significance greater than 5 σ . The signal persisted in the LIGO frequency band for approximately 1 s, increasing in frequency and amplitude over about 55 cycles from 35 to 450 Hz, and reached a peak gravitational strain of 3. 4-0.9+0.7×10-22 . The inferred source-frame initial black hole masses are 14.2-3.7+8.3 M⊙ and 7. 5-2.3+2.3 M⊙, and the final black hole mass is 20.8-1.7+6.1 M⊙. We find that at least one of the component black holes has spin greater than 0.2. This source is located at a luminosity distance of 44 0-190+180 Mpc corresponding to a redshift of 0.0 9-0.04+0.03. All uncertainties define a 90% credible interval. This second gravitational-wave observation provides improved constraints on stellar populations and on deviations from general relativity.

  1. Titius-Bode law in the Solar System. Dependence of the regularity parameter on the central body mass

    NASA Astrophysics Data System (ADS)

    Georgiev, Tsvetan B.

    2016-07-01

    Near-commensurability of the orbital sizes or periods exists in the Solar system for the massive planets and the massive satellites of Jupiter, Saturn and Uranus. It is well revealed by the Titius-Bode law (TBL) long ago by Dermott (1968), but is not been explained convincingly yet. Independently on this fact, the question about the dependence of the scale constant of the TBL on the mass of the central body is open. In this paper we show such a dependence. Due to the dynamic evolution the orbits of the massive planets and satellites may be in a transient stage when a primary TBL is well pronounced. Simultaneously a secondary TBL, a trail from the past as a hint for the future, may be less pronounced. The TBL is fitted after the numeration of the objects. For this reason we derive a special "curve" and we use 2 its minimums to introduce a primary and a secondary numeration for the objects. Thus we derive constants of 2 TBLs and build the searched dependence by twice as many points. In this paper we show and use pairs of TBLs for the satellite systems of Jupiter, Saturn, Uranus, Neptune and Pluto, as well as for the solar system in two cases - with 4 massive planets and with 8 massive planets. In fig. 10 we show the statistically significant dependences where the coefficient of the near-commensurability for the orbital sizes varies from about 1.3 for the satellites of Pluto to about 1.7 for the planets of the Sun.

  2. CH3 NH3 PbBr3 -CH3 NH3 PbI3 Perovskite-Perovskite Tandem Solar Cells with Exceeding 2.2 V Open Circuit Voltage.

    PubMed

    Heo, Jin Hyuck; Im, Sang Hyuk

    2016-07-01

    Perovskite-perovskite tandem solar cells with open-circuit voltages of over 2.2 V are reported. These cost-effective, solution-processible perovskite hybrid tandem solar cells with high open-circuit voltages are fabricated by the simple lamination of a front planar MAPbBr3 perovskite cell and a back MAPbI3 planar perovskite solar cell.

  3. Nearby solar-type star with a low-mass companion - New sensitivity limits reached using speckle imaging

    NASA Astrophysics Data System (ADS)

    Henry, Todd J.; McCarthy, Donald W., Jr.; Freeman, Jonathan; Christou, Julian C.

    1992-04-01

    The low-mass companion to the nearby solar-type star Gliese 67 is imaged using 2D IR speckle imaging techniques. The binary is resolved at J (1.25 micron), H (1.65 micron), and K (2.2 microns) to determine the magnitudes and colors of the components. In observations spanning 14 months the secondary is found at separations and position angles predicted by the astrometric orbit, and the component masses are found to be 0.97 and 0.29 solar mass. With a magnitude difference of 4.5 mag at K, these observations define a new sensitivity limit for companions at subarcsecond scales, 6-9 AU for the observations reported here of the Gliese 67 system. For the G dwarf/M dwarf pair, this brightness ratio corresponds to 7.5 mag at V, or a flux ratio of 1000. The data indicate that even greater sensitivity is possible, to companions six magnitudes fainter than their primaries in the infrared, thereby allowing us to search for very low-mass secondaries orbiting nearby solar-type stars.

  4. MAGNETOHYDRODYNAMIC SIMULATION OF THE X2.2 SOLAR FLARE ON 2011 FEBRUARY 15. II. DYNAMICS CONNECTING THE SOLAR FLARE AND THE CORONAL MASS EJECTION

    SciTech Connect

    Inoue, S.; Magara, T.; Choe, G. S.; Hayashi, K.; Park, Y. D.

    2015-04-20

    We clarify a relationship between the dynamics of a solar flare and a growing coronal mass ejection (CME) by investigating the dynamics of magnetic fields during the X2.2-class flare taking place in the solar active region 11158 on 2011 February 15, based on simulation results obtained from Inoue et al. We found that the strongly twisted lines formed through tether-cutting reconnection in the twisted lines of a nonlinear force-free field can break the force balance within the magnetic field, resulting in their launch from the solar surface. We further discover that a large-scale flux tube is formed during the eruption as a result of the tether-cutting reconnection between the eruptive strongly twisted lines and these ambient weakly twisted lines. The newly formed large flux tube exceeds the critical height of the torus instability. Tether-cutting reconnection thus plays an important role in the triggering of a CME. Furthermore, we found that the tangential fields at the solar surface illustrate different phases in the formation of the flux tube and its ascending phase over the threshold of the torus instability. We will discuss these dynamics in detail.

  5. The total number of spicules on the solar surface and their role in heating and mass balanace in the solar corona

    NASA Astrophysics Data System (ADS)

    Mamedov, S. G.; Kuli-Zade, D. M.; Alieva, Z. F.; Musaev, M. M.; Mustafa, F. R.

    2016-09-01

    A critical review of determinations of the number of spicules is presented, and the role of both classical and Type 2 spicules in heating and mass balance in the corona is considered. The total number of Type 2 spicules is determined, together with the upward fluxes of energy and mass to which they give rise. The total number of Type 2 spicules on the solar surface is found to be ~105, close to values obtained in other studies. The associated particle flux toward the corona is 2.5 × 1014 cm-2 s-1, an order of magnitude lower than the corresponding flux for classical spicules. The associated energy flux is 104 erg cm-2 s-1, an order of magnaitude lower than estimates obtained in other studies. The results indicate that Type 2 spicules can supply the mass lost from the corona, but are not able to fully explain coronal energy losses.

  6. PREDICTION OF TYPE II SOLAR RADIO BURSTS BY THREE-DIMENSIONAL MHD CORONAL MASS EJECTION AND KINETIC RADIO EMISSION SIMULATIONS

    SciTech Connect

    Schmidt, J. M.; Cairns, Iver H.; Hillan, D. S.

    2013-08-20

    Type II solar radio bursts are the primary radio emissions generated by shocks and they are linked with impending space weather events at Earth. We simulate type II bursts by combining elaborate three-dimensional MHD simulations of realistic coronal mass ejections (CMEs) at the Sun with an analytic kinetic radiation theory developed recently. The modeling includes initialization with solar magnetic and active region fields reconstructed from magnetograms of the Sun, a flux rope of the initial CME dimensioned with STEREO spacecraft observations, and a solar wind driven with averaged empirical data. We demonstrate impressive accuracy in time, frequency, and intensity for the CME and type II burst observed on 2011 February 15. This implies real understanding of the physical processes involved regarding the radio emission excitation by shocks and supports the near-term development of a capability to predict and track these events for space weather prediction.

  7. Solar abundances and the role of nucleogenesis in low-to-medium mass stars in the galaxy

    NASA Technical Reports Server (NTRS)

    Aller, L. H.

    1985-01-01

    The pattern of solar elemental abundances agrees well with that shown by Cl chondrites for nonvolatile elements. For metals of the iron peak, the chief source of uncertainty seems to be the structure of the solar atmosphere. Lines of rare elements are frequently masked by atomic and molecular lines of abundant species. The vast majority of stars (including the sun) will do little to change the bulk composition of the interstellar medium from which new stars are formed. He, C, and N in small quantities are supplied by stars from 1 to 8 solar masses as they evolve and produce nebular envelopes that dissipate into the interstellar medium, but as has long been recognized, oxygen, heavier elements, and all r-process and proton-rich nuclides are made in massive stars.

  8. Solar Radiation Pressure Estimation and Analysis of a GEO Class of High Area-to-Mass Ratio Debris Objects

    NASA Technical Reports Server (NTRS)

    Kelecy, Tom; Payne, Tim; Thurston, Robin; Stansbery, Gene

    2007-01-01

    A population of deep space objects is thought to be high area-to-mass ratio (AMR) debris having origins from sources in the geosynchronous orbit (GEO) belt. The typical AMR values have been observed to range anywhere from 1's to 10's of m(sup 2)/kg, and hence, higher than average solar radiation pressure effects result in long-term migration of eccentricity (0.1-0.6) and inclination over time. However, the nature of the debris orientation-dependent dynamics also results time-varying solar radiation forces about the average which complicate the short-term orbit determination processing. The orbit determination results are presented for several of these debris objects, and highlight their unique and varied dynamic attributes. Estimation or the solar pressure dynamics over time scales suitable for resolving the shorter term dynamics improves the orbit estimation, and hence, the orbit predictions needed to conduct follow-up observations.

  9. COUPLING THE SOLAR DYNAMO AND THE CORONA: WIND PROPERTIES, MASS, AND MOMENTUM LOSSES DURING AN ACTIVITY CYCLE

    SciTech Connect

    Pinto, Rui F.; Brun, Allan Sacha; Grappin, Roland

    2011-08-20

    We study the connections between the Sun's convection zone and the evolution of the solar wind and corona. We let the magnetic fields generated by a 2.5-dimensional (2.5D) axisymmetric kinematic dynamo code (STELEM) evolve in a 2.5D axisymmetric coronal isothermal magnetohydrodynamic code (DIP). The computations cover an 11 year activity cycle. The solar wind's asymptotic velocity varies in latitude and in time in good agreement with the available observations. The magnetic polarity reversal happens at different paces at different coronal heights. Overall the Sun's mass-loss rate, momentum flux, and magnetic braking torque vary considerably throughout the cycle. This cyclic modulation is determined by the latitudinal distribution of the sources of open flux and solar wind and the geometry of the Alfven surface. Wind sources and braking torque application zones also vary accordingly.

  10. Destruction of Sun-Grazing Comet C-2011 N3 (SOHO) Within the Low Solar Corona

    NASA Technical Reports Server (NTRS)

    Schrijver, C. J.; Brown, J. C.; Battams, K.; Saint-Hilaire, P.; Liu, W.; Hudson, H.; Pesnell, W. D.

    2012-01-01

    Observations of comets in Sun-grazing orbits that survive solar insolation long enough to penetrate into the Suns inner corona provide information on the solar atmosphere and magnetic field as well as on the makeup of the comet. On 6 July 2011, the Solar Dynamics Observatory (SDO) observed the demise of comet C2011 N3 (SOHO) within the low solar corona in five wavelength bands in the extreme ultraviolet (EUV). The comet penetrated to within 0.146 solarradius (100,000 kilometers) of the solar surface before its EUV signal disappeared.

  11. Nano metal-enhanced power conversion efficiency in CH3NH3PbI3 solar cells

    NASA Astrophysics Data System (ADS)

    Yu, Jing; Zhang, Chao; Yang, Siyu; Chen, Meina; Lei, Fengcai; Man, Baoyuan

    2017-04-01

    Nano metal-enhanced power conversion efficiency (PCE) in CH3NH3PbI3 solar cells utilizing the forward scattering effect of metal nanoparticles has been researched in this paper by finite difference time domain method. Two structures are designed in the research to explore this feasibility, by adjusting the materials, sizes and surface coverages of metal nanoparticles, both of them exhibit the exciting results bringing the max PCE enhancements by 12.18% and 8.03% respectively. Especially, considering the huge handleability of the second structure, this method has large applications in further improving the performance for other perovskite solar cells.

  12. Forbidden Zones for Circular Regular Orbits of the Moons in Solar System, R3BP

    NASA Astrophysics Data System (ADS)

    Ershkov, Sergey V.

    2017-03-01

    Previously, we have considered the equations of motion of the three-body problem in a Lagrange form (which means a consideration of relative motions of 3-bodies in regard to each other). Analysing such a system of equations, we considered the case of small-body motion of negligible mass m 3 around the second of two giant-bodies m 1, m 2 ( which are rotating around their common centre of masses on Kepler's trajectories), the mass of which is assumed to be less than the mass of central body. In the current development, we have derived a key parameter η that determines the character of quasi-circular motion of the small third body m 3 relative to the second body m 2 (planet). Namely, by making several approximations in the equations of motion of the three-body problem, such the system could be reduced to the key governing Riccati-type ordinary differential equations. Under assumptions of R3BP (restricted three-body problem), we additionally note that Riccati-type ODEs above should have the invariant form if the key governing (dimensionless) parameter η remains in the range 10-2[InlineMediaObject not available: see fulltext.] 10-3. Such an amazing fact let us evaluate the forbidden zones for Moon's orbits in the inner solar system or the zones of distances ( between Moon and Planet) for which the motion of small body could be predicted to be unstable according to basic features of the solutions of Riccati-type.

  13. Tuning superior solar cell performance of carrier mobility and absorption in perovskite CH3NH3GeCl3: A density functional calculations

    NASA Astrophysics Data System (ADS)

    Zhao, Yu-Qing; Wu, Li-Juan; Liu, Biao; Wang, Ling-Zhi; He, Peng-Bin; Cai, Meng-Qiu

    2016-05-01

    The solar cell based on hybrid organic-inorganic halide perovskite has received considerable attention. One of the most important issues in the pursuit of further developments in this area is to obtain both a high carrier mobility and an excellent ability of light adsorption. In this paper, we investigate the electronic structure and electronic effective masses of the new non-toxic material CH3NH3GeCl3 by first-principle calculations. The results show that the absorption efficiency of CH3NH3GeCl3 is more superior to that of CH3NH3PbI3 in short wavelength region. We trace this result to the ferroelectricity caused by the more serious octahedral GeCl6- distortion. We also discover a new relationship between the carrier effective masses anisotropy and the anisotropy of electronic density of states along three principal directions. Moreover, while applied the isotropic compressive pressure, the absorption efficiency and carrier mobility of CH3NH3GeCl3 in orthorhombic phase are improved greatly due to changes of electronic structure. We speculate that these are general results of tuning of the carrier mobility by controlling the band gap and the electronic occupation along different directions, to obtain both a high carrier mobility and an excellent ability of light adsorption.

  14. Thermally Induced Vibrations of the Hubble Space Telescope's Solar Array 3 in a Test Simulated Space Environment

    NASA Technical Reports Server (NTRS)

    Early, Derrick A.; Haile, William B.; Turczyn, Mark T.; Griffin, Thomas J. (Technical Monitor)

    2001-01-01

    NASA Goddard Space Flight Center and the European Space Agency (ESA) conducted a disturbance verification test on a flight Solar Array 3 (SA3) for the Hubble Space Telescope using the ESA Large Space Simulator (LSS) in Noordwijk, the Netherlands. The LSS cyclically illuminated the SA3 to simulate orbital temperature changes in a vacuum environment. Data acquisition systems measured signals from force transducers and accelerometers resulting from thermally induced vibrations of the SAI The LSS with its seismic mass boundary provided an excellent background environment for this test. This paper discusses the analysis performed on the measured transient SA3 responses and provides a summary of the results.

  15. Relativistic GW calculations on CH3NH3PbI3 and CH3NH3SnI3 Perovskites for Solar Cell Applications

    NASA Astrophysics Data System (ADS)

    Umari, Paolo; Mosconi, Edoardo; de Angelis, Filippo

    2014-03-01

    Hybrid AMX3 perovskites (A = Cs, CH3NH3; M = Sn, Pb; X = halide) have revolutionized the scenario of emerging photovoltaic technologies, with very recent results demonstrating 15% efficient solar cells. The CH3NH3PbI3/MAPb(I1-xClx)3 perovskites have dominated the field, while the similar CH3NH3SnI3 has not been exploited for photovoltaic applications. Replacement of Pb by Sn would facilitate the large uptake of perovskite-based photovoltaics. Despite the extremely fast progress, the materials electronic properties which are key to the photovoltaic performance are relatively little understood. Density Functional Theory electronic structure methods have so far delivered an unbalanced description of Pb- and Sn-based perovskites. Here we develop an effective GW method incorporating spin-orbit coupling which allows us to accurately model the electronic, optical and transport properties of CH3NH3SnI3 and CH3NH3PbI3, opening the way to new materials design. The different CH3NH3SnI3 and CH3NH3PbI3 electronic properties are discussed in light of their exploitation for solar cells, and found to be dominantly due to relativistic effects. These effects stabilize the CH3NH3PbI3 material towards oxidation, by inducing a deeper valence band edge. Relativistic effects, however, also increase the material band-gap compared to CH3NH3SnI3, due to the valence band energy downshift (~0.7 eV) being only partly compensated by the conduction band downshift (~0.2 eV).

  16. Study of the geoeffectiveness of coronal mass ejections, corotating interaction regions and their associated structures observed during Solar Cycle 23

    NASA Astrophysics Data System (ADS)

    Badruddin, A.; Falak, Z.

    2016-08-01

    The interplanetary coronal mass ejections (ICMEs) and the corotating interaction regions (CIRs) are the two most important structures of the interplanetary medium affecting the Earth and the near-Earth space environment. We study the solar wind-magnetosphere coupling during the passage of ICMEs and CIRs, in the Solar Cycle 23 (Jan. 1995-Dec. 2009), and their relative geoeffectiveness. We utilize the timings of different features of these structures, their arrival and duration. As geomagnetic parameter, we utilize high time resolution data of Dst and AE indices. In addition to these geomagnetic indices, we utilize the simultaneous and similar time resolution data of interplanetary plasma and field, namely, solar wind velocity, interplanetary magnetic field, its north-south component and dawn-dusk electric field. We apply the method of superposed epoch analysis. Utilizing the properties of various structures during the passage of ICMEs and CIRs, and variations observed in plasma and field parameters during their passage along with the simultaneous changes observed in geomagnetic parameters, we identify the interplanetary conditions, plasma/field parameters and their relative importance in solar wind-magnetosphere coupling. Geospace consequences of ICMEs and CIRs, and the implications of these results for solar wind-magnetosphere coupling are discussed.

  17. Interplanetary Coronal Mass Ejections Resulting from Earth-Directed CMEs Using SOHO and ACE Combined Data During Solar Cycle 23

    NASA Astrophysics Data System (ADS)

    Paouris, Evangelos; Mavromichalaki, Helen

    2017-02-01

    In this work a total of 266 interplanetary coronal mass ejections observed by the Solar and Heliospheric Observatory/ Large Angle and Spectrometric Coronagraph (SOHO/LASCO) and then studied by in situ observations from Advanced Composition Explorer (ACE) spacecraft, are presented in a new catalog for the time interval 1996 - 2009 covering Solar Cycle 23. Specifically, we determine the characteristics of the CME which is responsible for the upcoming ICME and the associated solar flare, the initial/background solar wind plasma and magnetic field conditions before the arrival of the CME, the conditions in the sheath of the ICME, the main part of the ICME, the geomagnetic conditions of the ICME's impact at Earth and finally we remark on the visual examination for each event. Interesting results revealed from this study include the high correlation coefficient values of the magnetic field Bz component against the Ap index (r = 0.84), as well as against the Dst index (r = 0.80) and of the effective acceleration against the CME linear speed (r = 0.98). We also identify a north-south asymmetry for X-class solar flares and an east-west asymmetry for CMEs associated with strong solar flares (magnitude ≥ M1.0) which finally triggered intense geomagnetic storms (with Ap ≥179). The majority of the geomagnetic storms are determined to be due to the ICME main part and not to the extreme conditions which dominate inside the sheath. For the intense geomagnetic storms the maximum value of the Ap index is observed almost 4 hours before the minimum Dst index. The amount of information makes this new catalog the most comprehensive ICME catalog for Solar Cycle 23.

  18. Solar Wind Sputtering of Lunar Soil Analogs: The Effect of Ionic Charge and Mass

    NASA Technical Reports Server (NTRS)

    Hijazi, H.; Bannister, M. E.; Meyer, F. W.; Rouleau, C. M.; Barghouty, A. F.; Rickman, D. L.; Hijazi, H.

    2014-01-01

    In this contribution we report sput-tering measurements of anorthite, an analog material representative of the lunar highlands, by singly and multicharged ions representative of the solar wind. The ions investigated include protons, as well as singly and multicharged Ar ions (as proxies for the heavier solar wind constituents), in the charge state range +1 to +9, and had a fixed solar-wind-relevant impact velocity of approximately 310 km/s or 500 eV/ amu. The goal of the measurements was to determine the sputtering contribution of the heavy, multicharged minority solar wind constituents in comparison to that due to the dominant H+ fraction.

  19. A Search for Early Optical Emission at Gamma-Ray Burst Locations by the Solar Mass Ejection Imager (SMEI)

    NASA Technical Reports Server (NTRS)

    Band, David L.; Buffington, Andrew; Jackson, Bernard V.; Hick, P. Paul; Smith, Aaron C.

    2005-01-01

    The Solar Mass Ejection Imager (SMEI) views nearly every point on the sky once every 102 minutes and can detect point sources as faint as R approx. 10th magnitude. Therefore, SMEI can detect or provide upper limits for the optical afterglow from gamma-ray bursts in the tens of minutes after the burst when different shocked regions may emit optically. Here we provide upper limits for 58 bursts between 2003 February and 2005 April.

  20. H-2, H-3, He-3 production in solar flares. [using updated cross sections and kinematics

    NASA Technical Reports Server (NTRS)

    Ramaty, R.; Kozlovsky, B.

    1974-01-01

    The production of deuterium, tritium, and helium-3 from nuclear reactions of accelerated charged particles is evaluated with the ambient solar atmosphere. Updated cross sections and kinematics are used, calculations are extended to very low energies (approximates 0.1 MeV/nucleon), and the angular distribution of the secondary particles is calculated. The calculations are compared with data on accelerated isotopes from solar flares. In particular, the August 1972 events are considered for which both He-3 and nuclear gamma rays were observed. An explanation for He-3-rich events is provided in terms of the angular distributions of secondary isotopes, and the flux of 2.2 MeV gamma rays from such flares are also predicted.

  1. Probing the cosmic ray mass composition in the knee region through TeV secondary particle fluxes from solar surroundings

    NASA Astrophysics Data System (ADS)

    Banik, Prabir; Bijay, Biplab; Sarkar, Samir K.; Bhadra, Arunava

    2017-03-01

    The possibility of estimating the mass composition of primary cosmic rays above the knee of their energy spectrum through the study of high-energy gamma rays, muons, and neutrinos produced in the interactions of cosmic rays with solar ambient matter and radiation is explored. It is found that the theoretical fluxes of TeV gamma rays, muons, and neutrinos from a region around 15° of the Sun are sensitive to a mass composition of cosmic rays in the PeV energy range. The experimental prospects for the detection of such TeV gamma rays/neutrinos by future experiments are discussed.

  2. Comparing Solar Wind Velocity Measurements Derived from Sun-grazing Comet Lovejoy (C/2011 W3) with Solar Wind Models

    NASA Astrophysics Data System (ADS)

    Ramanjooloo, Y.; Jones, G. H.; Coates, A. J.; Owens, M. J.; Battams, K.

    2012-12-01

    Comets' plasma (type I) tails have been studied as natural probes of the solar wind since the mid-20th century. Local solar wind conditions directly control the morphology and dynamics of a comet's plasma tail. During ideal observing geometries, the orientation and structure of the plasma tail can reveal large-scale and small-scale variations in the local solar wind structure. We present solar wind velocity measurements derived from multiple observing locations of comet Lovejoy (C/2011 W3) from the 14th - 19th December 2011 using recent images from the SECCHI and LASCO heliospheric imagers and coronagraphs aboard STEREO A and B, and SOHO. Overlapping observation sessions from the three spacecraft provided the perfect opportunity to use comet Lovejoy as a diagnostic tool to understand solar wind variability close to the Sun. Our unique analysis technique [submitted] allows us to determine the latitudinal variations of the solar wind, heliospheric current sheet sector boundaries and the boundaries of transient features as comet Lovejoy probes the Sun's atmosphere. We plan to compare our observations to results of suitable simulations of plasma conditions in the corona and inner heliosphere during the time of Lovejoy's perihelion passage.

  3. Solar Energy: The State of the Art, Part 3

    ERIC Educational Resources Information Center

    Miller, Charles D.; Pinelli, Tomas E.

    1976-01-01

    Bioconversion to fuels, ocean thermal-gradient power conversion, and energy systems are discussed in this last article of a three-part series on solar energy. It is noted that solar research has near-term and long-term implications for the housing industry, manufacturers of components designed for homes, and the public in general, and that…

  4. 3D reconstruction and particle acceleration properties of Coronal Shock Waves During Powerful Solar Particle Events

    NASA Astrophysics Data System (ADS)

    Plotnikov, Illya; Vourlidas, Angelos; Tylka, Allan J.; Pinto, Rui; Rouillard, Alexis; Tirole, Margot

    2016-07-01

    Identifying the physical mechanisms that produce the most energetic particles is a long-standing observational and theoretical challenge in astrophysics. Strong pressure waves have been proposed as efficient accelerators both in the solar and astrophysical contexts via various mechanisms such as diffusive-shock/shock-drift acceleration and betatron effects. In diffusive-shock acceleration, the efficacy of the process relies on shock waves being super-critical or moving several times faster than the characteristic speed of the medium they propagate through (a high Alfven Mach number) and on the orientation of the magnetic field upstream of the shock front. High-cadence, multipoint imaging using the NASA STEREO, SOHO and SDO spacecrafts now permits the 3-D reconstruction of pressure waves formed during the eruption of coronal mass ejections. Using these unprecedented capabilities, some recent studies have provided new insights on the timing and longitudinal extent of solar energetic particles, including the first derivations of the time-dependent 3-dimensional distribution of the expansion speed and Mach numbers of coronal shock waves. We will review these recent developments by focusing on particle events that occurred between 2011 and 2015. These new techniques also provide the opportunity to investigate the enigmatic long-duration gamma ray events.

  5. Age Dependence of Wind Properties for Solar-type Stars: A 3D Study

    NASA Astrophysics Data System (ADS)

    Réville, Victor; Folsom, Colin P.; Strugarek, Antoine; Brun, Allan Sacha

    2016-12-01

    Young and rapidly rotating stars are known for intense, dynamo-generated magnetic fields. Spectropolarimetric observations of those stars in precisely aged clusters are key input for gyrochronology and magnetochronology. We use Zeeman Doppler imaging maps of several young K-type stars of similar mass and radius but with various ages and rotational periods to perform three-dimensional (3D) numerical MHD simulations of their coronae and follow the evolution of their magnetic properties with age. Those simulations yield the coronal structure as well as the instant torque exerted by the magnetized, rotating wind on the star. As stars get older, we find that the angular momentum loss decreases with {{{Ω }}}\\star 3, which is the reason for the convergence on the Skumanich law. For the youngest stars of our sample, the angular momentum loss shows signs of saturation around 8{{{Ω }}}⊙ , which is a common value used in spin evolution models for K-type stars. We compare these results to semianalytical models and existing braking laws. We observe a complex wind-speed distribution for the youngest stars with slow, intermediate, and fast wind components, which are the result of interaction with intense and nonaxisymmetric magnetic fields. Consequently, in our simulations, the stellar wind structure in the equatorial plane of young stars varies significantly from a solar configuration, delivering insight about the past of the solar system interplanetary medium.

  6. Measurements and an empirical model of the Zodiacal brightness as observed by the Solar Mass Ejection Imager (SMEI)

    NASA Astrophysics Data System (ADS)

    Buffington, Andrew; Bisi, Mario M.; Clover, John M.; Hick, P. Paul; Jackson, Bernard V.; Kuchar, Thomas A.; Price, Stephan D.

    2016-07-01

    The Solar Mass Ejection Imager (SMEI) provided near-full-sky broadband visible-light photometric maps for 8.5 years from 2003 to 2011. At a cadence of typically 14 maps per day, these each have an angular resolution of about 0.5º and differential photometric stability of about 1% throughout this time. When individual bright stars are removed from the maps and an empirical sidereal background subtracted, the residue is dominated by the zodiacal light. This sky coverage enables the formation of an empirical zodiacal-light model for observations at 1 AU which summarizes the SMEI data. When this is subtracted, analysis of the ensemble of residual sky maps sets upper limits of typically 1% for potential secular change of the zodiacal light for each of nine chosen ecliptic sky locations. An overall long-term photometric stability of 0.25% is certified by analysis of three stable sidereal objects. Averaging the nine ecliptic results together yields a 1-σ upper limit of 0.3% for zodiacal light change over this 8.5 year period.

  7. Measurements and an Empirical Model of the Zodiacal Brightness as Observed by the Solar Mass Ejection Imager (SMEI)

    NASA Astrophysics Data System (ADS)

    Buffington, A.; Bisi, M. M.; Clover, J. M.; Hick, P. P.; Jackson, B. V.; Kuchar, T. A.; Price, S. D.

    2015-12-01

    The Solar Mass Ejection Imager (SMEI) has provided near-full-sky broadband visible-light photometric maps for 8.5 years from 2003 to 2011. These have an angular resolution of about 0.5º and differential photometric stability of about 1% per map throughout this time. When individual bright stars are removed from the maps and an empirical sidereal background subtracted, the residue is dominated by the zodiacal light. This sky coverage enables the formation of an empirical zodiacal-light model for observations at 1 AU which summarizes the SMEI data. When this is subtracted, analysis of the ensemble of residual sky maps sets upper limits of typically 1% for potential secular change of the zodiacal light for each of nine chosen ecliptic sky locations. An overall long-term photometric stability of 0.25% is certified by analysis of three stable sidereal objects. Averaging the nine ecliptic results together yields a 1-σ upper limit of 0.3% for zodiacal light change over this 8.5 year period.

  8. GW151226: Observation of Gravitational Waves from a 22-Solar-Mass Binary Black Hole Coalescence.

    PubMed

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Blair, C D; Blair, D G; Blair, R M; Bloemen, S; Bock, O; Boer, M; Bogaert, G; Bogan, C; Bohe, A; Bond, C; Bondu, F; Bonnand, R; Boom, B A; Bork, R; Boschi, V; Bose, S; Bouffanais, Y; Bozzi, A; Bradaschia, C; Brady, P R; Braginsky, V B; Branchesi, M; Brau, J E; Briant, T; Brillet, A; Brinkmann, M; Brisson, V; Brockill, P; Broida, J E; Brooks, A F; Brown, D A; Brown, D D; Brown, N M; Brunett, S; Buchanan, C C; Buikema, A; Bulik, T; Bulten, H J; Buonanno, A; Buskulic, D; Buy, C; Byer, R L; Cabero, M; Cadonati, L; Cagnoli, G; Cahillane, C; Calderón Bustillo, J; Callister, T; Calloni, E; Camp, J B; Cannon, K C; Cao, J; Capano, C D; Capocasa, E; Carbognani, F; Caride, S; Casanueva Diaz, J; Casentini, C; Caudill, S; Cavaglià, M; Cavalier, F; Cavalieri, R; Cella, G; Cepeda, C B; Cerboni Baiardi, L; Cerretani, G; Cesarini, E; Chamberlin, S J; Chan, M; Chao, S; Charlton, P; Chassande-Mottin, E; Cheeseboro, B D; Chen, H Y; Chen, Y; Cheng, C; Chincarini, A; Chiummo, A; Cho, H S; Cho, M; Chow, J H; Christensen, N; Chu, Q; Chua, S; Chung, S; Ciani, G; Clara, F; Clark, J A; Cleva, F; Coccia, E; Cohadon, P-F; Colla, A; Collette, C G; Cominsky, L; Constancio, M; Conte, A; Conti, L; Cook, D; Corbitt, T R; Cornish, N; Corsi, A; Cortese, S; Costa, C A; Coughlin, M W; Coughlin, S B; Coulon, J-P; Countryman, S T; Couvares, P; Cowan, E E; Coward, D M; Cowart, M J; Coyne, D C; Coyne, R; Craig, K; Creighton, J D E; Cripe, J; Crowder, S G; Cumming, A; Cunningham, L; Cuoco, E; Dal Canton, T; Danilishin, S L; D'Antonio, S; Danzmann, K; Darman, N S; Dasgupta, A; Da Silva Costa, C F; Dattilo, V; Dave, I; Davier, M; Davies, G S; Daw, E J; Day, R; De, S; DeBra, D; Debreczeni, G; Degallaix, J; De Laurentis, M; Deléglise, S; Del Pozzo, W; Denker, T; Dent, T; Dergachev, V; De Rosa, R; DeRosa, R T; DeSalvo, R; Devine, R C; Dhurandhar, S; Díaz, M C; Di Fiore, L; Di Giovanni, M; Di Girolamo, T; Di Lieto, A; Di Pace, S; Di Palma, I; Di Virgilio, A; Dolique, V; Donovan, F; Dooley, K L; Doravari, S; Douglas, R; Downes, T P; Drago, M; Drever, R W P; Driggers, J C; Ducrot, M; Dwyer, S E; Edo, T B; Edwards, M C; Effler, A; Eggenstein, H-B; Ehrens, P; Eichholz, J; Eikenberry, S S; Engels, W; Essick, R C; Etzel, T; Evans, M; Evans, T M; Everett, R; Factourovich, M; Fafone, V; Fair, H; Fairhurst, S; Fan, X; Fang, Q; Farinon, S; Farr, B; Farr, W M; Favata, M; Fays, M; Fehrmann, H; Fejer, M M; Fenyvesi, E; Ferrante, I; Ferreira, E C; Ferrini, F; Fidecaro, F; Fiori, I; Fiorucci, D; Fisher, R P; Flaminio, R; Fletcher, M; Fong, H; Fournier, J-D; Frasca, S; Frasconi, F; Frei, Z; Freise, A; Frey, R; Frey, V; Fritschel, P; Frolov, V V; Fulda, P; Fyffe, M; Gabbard, H A G; Gair, J R; Gammaitoni, L; Gaonkar, S G; Garufi, F; Gaur, G; Gehrels, N; Gemme, G; Geng, P; Genin, E; Gennai, A; George, J; Gergely, L; Germain, V; Ghosh, Abhirup; Ghosh, Archisman; Ghosh, S; Giaime, J A; Giardina, K D; Giazotto, A; Gill, K; Glaefke, A; Goetz, E; Goetz, R; Gondan, L; González, G; Gonzalez Castro, J M; Gopakumar, A; Gordon, N A; Gorodetsky, M L; Gossan, S E; Gosselin, M; Gouaty, R; Grado, A; Graef, C; Graff, P B; Granata, M; Grant, A; Gras, S; Gray, C; Greco, G; Green, A C; Groot, P; Grote, H; Grunewald, S; Guidi, G M; Guo, X; Gupta, A; Gupta, M K; Gushwa, K E; Gustafson, E K; Gustafson, R; Hacker, J J; Hall, B R; Hall, E D; Hamilton, H; Hammond, G; Haney, M; Hanke, M M; Hanks, J; Hanna, C; Hannam, M D; Hanson, J; Hardwick, T; Harms, J; Harry, G M; Harry, I W; Hart, M J; Hartman, M T; Haster, C-J; Haughian, K; Healy, J; Heidmann, A; Heintze, M C; Heitmann, H; Hello, P; Hemming, G; Hendry, M; Heng, I S; Hennig, J; Henry, J; Heptonstall, A W; Heurs, M; Hild, S; Hoak, D; Hofman, D; Holt, K; Holz, D E; Hopkins, P; Hough, J; Houston, E A; Howell, E J; Hu, Y M; Huang, S; Huerta, E A; Huet, D; Hughey, B; Husa, S; Huttner, S H; Huynh-Dinh, T; Indik, N; Ingram, D R; Inta, R; Isa, H N; Isac, J-M; Isi, M; Isogai, T; Iyer, B R; Izumi, K; Jacqmin, T; Jang, H; Jani, K; Jaranowski, P; Jawahar, S; Jian, L; Jiménez-Forteza, F; Johnson, W W; Johnson-McDaniel, N K; Jones, D I; Jones, R; Jonker, R J G; Ju, L; K, Haris; Kalaghatgi, C V; Kalogera, V; Kandhasamy, S; Kang, G; Kanner, J B; Kapadia, S J; Karki, S; Karvinen, K S; Kasprzack, M; Katsavounidis, E; Katzman, W; Kaufer, S; Kaur, T; Kawabe, K; Kéfélian, F; Kehl, M S; Keitel, D; Kelley, D B; Kells, W; Kennedy, R; Key, J S; Khalili, F Y; Khan, I; Khan, S; Khan, Z; Khazanov, E A; Kijbunchoo, N; Kim, Chi-Woong; Kim, Chunglee; Kim, J; Kim, K; Kim, N; Kim, W; Kim, Y-M; Kimbrell, S J; King, E J; King, P J; Kissel, J S; Klein, B; Kleybolte, L; Klimenko, S; Koehlenbeck, S M; Koley, S; Kondrashov, V; Kontos, A; Korobko, M; Korth, W Z; Kowalska, I; Kozak, D B; Kringel, V; Krishnan, B; Królak, A; Krueger, C; Kuehn, G; Kumar, P; Kumar, R; Kuo, L; Kutynia, A; Lackey, B D; Landry, M; Lange, J; Lantz, B; Lasky, P D; Laxen, M; Lazzarini, A; Lazzaro, C; Leaci, P; Leavey, S; Lebigot, E O; Lee, C H; Lee, H K; Lee, H M; Lee, K; Lenon, A; Leonardi, M; Leong, J R; Leroy, N; Letendre, N; Levin, Y; Lewis, J B; Li, T G F; Libson, A; Littenberg, T B; Lockerbie, N A; Lombardi, A L; London, L T; Lord, J E; Lorenzini, M; Loriette, V; Lormand, M; Losurdo, G; Lough, J D; Lousto, C O; Lück, H; Lundgren, A P; Lynch, R; Ma, Y; Machenschalk, B; MacInnis, M; Macleod, D M; Magaña-Sandoval, F; Magaña Zertuche, L; Magee, R M; Majorana, E; Maksimovic, I; Malvezzi, V; Man, N; Mandel, I; Mandic, V; Mangano, V; Mansell, G L; Manske, M; Mantovani, M; Marchesoni, F; Marion, F; Márka, S; Márka, Z; Markosyan, A S; Maros, E; Martelli, F; Martellini, L; Martin, I W; Martynov, D V; Marx, J N; Mason, K; Masserot, A; Massinger, T J; Masso-Reid, M; Mastrogiovanni, S; Matichard, F; Matone, L; Mavalvala, N; Mazumder, N; McCarthy, R; McClelland, D E; McCormick, S; McGuire, S C; McIntyre, G; McIver, J; McManus, D J; McRae, T; McWilliams, S T; Meacher, D; Meadors, G D; Meidam, J; Melatos, A; Mendell, G; Mercer, R A; Merilh, E L; Merzougui, M; Meshkov, S; Messenger, C; Messick, C; Metzdorff, R; Meyers, P M; Mezzani, F; Miao, H; Michel, C; Middleton, H; Mikhailov, E E; Milano, L; Miller, A L; Miller, A; Miller, B B; Miller, J; Millhouse, M; Minenkov, Y; Ming, J; Mirshekari, S; Mishra, C; Mitra, S; Mitrofanov, V P; Mitselmakher, G; Mittleman, R; Moggi, A; Mohan, M; Mohapatra, S R P; Montani, M; Moore, B C; Moore, C J; Moraru, D; Moreno, G; Morriss, S R; Mossavi, K; Mours, B; Mow-Lowry, C M; Mueller, G; Muir, A W; Mukherjee, Arunava; Mukherjee, D; Mukherjee, S; Mukund, N; Mullavey, A; Munch, J; Murphy, D J; Murray, P G; Mytidis, A; Nardecchia, I; Naticchioni, L; Nayak, R K; Nedkova, K; Nelemans, G; Nelson, T J N; Neri, M; Neunzert, A; Newton, G; Nguyen, T T; Nielsen, A B; Nissanke, S; Nitz, A; Nocera, F; Nolting, D; Normandin, M E N; Nuttall, L K; Oberling, J; Ochsner, E; O'Dell, J; Oelker, E; Ogin, G H; Oh, J J; Oh, S H; Ohme, F; Oliver, M; Oppermann, P; Oram, Richard J; O'Reilly, B; O'Shaughnessy, R; Ottaway, D J; Overmier, H; Owen, B J; Pai, A; Pai, S A; Palamos, J R; Palashov, O; Palomba, C; Pal-Singh, A; Pan, H; Pankow, C; Pannarale, F; Pant, B C; Paoletti, F; Paoli, A; Papa, M A; Paris, H R; Parker, W; Pascucci, D; Pasqualetti, A; Passaquieti, R; Passuello, D; Patricelli, B; Patrick, Z; Pearlstone, B L; Pedraza, M; Pedurand, R; Pekowsky, L; Pele, A; Penn, S; Perreca, A; Perri, L M; Pfeiffer, H P; Phelps, M; Piccinni, O J; Pichot, M; Piergiovanni, F; Pierro, V; Pillant, G; Pinard, L; Pinto, I M; Pitkin, M; Poe, M; Poggiani, R; Popolizio, P; Post, A; Powell, J; Prasad, J; Predoi, V; Prestegard, T; Price, L R; Prijatelj, M; Principe, M; Privitera, S; Prix, R; Prodi, G A; Prokhorov, L; Puncken, O; Punturo, M; Puppo, P; Pürrer, M; Qi, H; Qin, J; Qiu, S; Quetschke, V; Quintero, E A; Quitzow-James, R; Raab, F J; Rabeling, D S; Radkins, H; Raffai, P; Raja, S; Rajan, C; Rakhmanov, M; Rapagnani, P; Raymond, V; Razzano, M; Re, V; Read, J; Reed, C M; Regimbau, T; Rei, L; Reid, S; Reitze, D H; Rew, H; Reyes, S D; Ricci, F; Riles, K; Rizzo, M; Robertson, N A; Robie, R; Robinet, F; Rocchi, A; Rolland, L; Rollins, J G; Roma, V J; Romano, J D; Romano, R; Romanov, G; Romie, J H; Rosińska, D; Rowan, S; Rüdiger, A; Ruggi, P; Ryan, K; Sachdev, S; Sadecki, T; Sadeghian, L; Sakellariadou, M; Salconi, L; Saleem, M; Salemi, F; Samajdar, A; Sammut, L; Sanchez, E J; Sandberg, V; Sandeen, B; Sanders, J R; Sassolas, B; Sathyaprakash, B S; Saulson, P R; Sauter, O E S; Savage, R L; Sawadsky, A; Schale, P; Schilling, R; Schmidt, J; Schmidt, P; Schnabel, R; Schofield, R M S; Schönbeck, A; Schreiber, E; Schuette, D; Schutz, B F; Scott, J; Scott, S M; Sellers, D; Sengupta, A S; Sentenac, D; Sequino, V; Sergeev, A; Setyawati, Y; Shaddock, D A; Shaffer, T; Shahriar, M S; Shaltev, M; Shapiro, B; Shawhan, P; Sheperd, A; Shoemaker, D H; Shoemaker, D M; Siellez, K; Siemens, X; Sieniawska, M; Sigg, D; Silva, A D; Singer, A; Singer, L P; Singh, A; Singh, R; Singhal, A; Sintes, A M; Slagmolen, B J J; Smith, J R; Smith, N D; Smith, R J E; Son, E J; Sorazu, B; Sorrentino, F; Souradeep, T; Srivastava, A K; Staley, A; Steinke, M; Steinlechner, J; Steinlechner, S; Steinmeyer, D; Stephens, B C; Stevenson, S P; Stone, R; Strain, K A; Straniero, N; Stratta, G; Strauss, N A; Strigin, S; Sturani, R; Stuver, A L; Summerscales, T Z; Sun, L; Sunil, S; Sutton, P J; Swinkels, B L; Szczepańczyk, M J; Tacca, M; Talukder, D; Tanner, D B; Tápai, M; Tarabrin, S P; Taracchini, A; Taylor, R; Theeg, T; Thirugnanasambandam, M P; Thomas, E G; Thomas, M; Thomas, P; Thorne, K A; Thrane, E; Tiwari, S; Tiwari, V; Tokmakov, K V; Toland, K; Tomlinson, C; Tonelli, M; Tornasi, Z; Torres, C V; Torrie, C I; Töyrä, D; Travasso, F; Traylor, G; Trifirò, D; Tringali, M C; Trozzo, L; Tse, M; Turconi, M; Tuyenbayev, D; Ugolini, D; Unnikrishnan, C S; Urban, A L; Usman, S A; Vahlbruch, H; Vajente, G; Valdes, G; Vallisneri, M; van Bakel, N; van Beuzekom, M; van den Brand, J F J; Van Den Broeck, C; Vander-Hyde, D C; van der Schaaf, L; van Heijningen, J V; van Veggel, A A; Vardaro, M; Vass, S; Vasúth, M; Vaulin, R; Vecchio, A; Vedovato, G; Veitch, J; Veitch, P J; Venkateswara, K; Verkindt, D; Vetrano, F; Viceré, A; Vinciguerra, S; Vine, D J; Vinet, J-Y; Vitale, S; Vo, T; Vocca, H; Vorvick, C; Voss, D V; Vousden, W D; Vyatchanin, S P; Wade, A R; Wade, L E; Wade, M; Walker, M; Wallace, L; Walsh, S; Wang, G; Wang, H; Wang, M; Wang, X; Wang, Y; Ward, R L; Warner, J; Was, M; Weaver, B; Wei, L-W; Weinert, M; Weinstein, A J; Weiss, R; Wen, L; Weßels, P; Westphal, T; Wette, K; Whelan, J T; Whiting, B F; Williams, R D; Williamson, A R; Willis, J L; Willke, B; Wimmer, M H; Winkler, W; Wipf, C C; Wittel, H; Woan, G; Woehler, J; Worden, J; Wright, J L; Wu, D S; Wu, G; Yablon, J; Yam, W; Yamamoto, H; Yancey, C C; Yu, H; Yvert, M; Zadrożny, A; Zangrando, L; Zanolin, M; Zendri, J-P; Zevin, M; Zhang, L; Zhang, M; Zhang, Y; Zhao, C; Zhou, M; Zhou, Z; Zhu, X J; Zucker, M E; Zuraw, S E; Zweizig, J; Boyle, M; Hemberger, D; Kidder, L E; Lovelace, G; Ossokine, S; Scheel, M; Szilagyi, B; Teukolsky, S

    2016-06-17

    We report the observation of a gravitational-wave signal produced by the coalescence of two stellar-mass black holes. The signal, GW151226, was observed by the twin detectors of the Laser Interferometer Gravitational-Wave Observatory (LIGO) on December 26, 2015 at 03:38:53 UTC. The signal was initially identified within 70 s by an online matched-filter search targeting binary coalescences. Subsequent off-line analyses recovered GW151226 with a network signal-to-noise ratio of 13 and a significance greater than 5σ. The signal persisted in the LIGO frequency band for approximately 1 s, increasing in frequency and amplitude over about 55 cycles from 35 to 450 Hz, and reached a peak gravitational strain of 3.4_{-0.9}^{+0.7}×10^{-22}. The inferred source-frame initial black hole masses are 14.2_{-3.7}^{+8.3}M_{⊙} and 7.5_{-2.3}^{+2.3}M_{⊙}, and the final black hole mass is 20.8_{-1.7}^{+6.1}M_{⊙}. We find that at least one of the component black holes has spin greater than 0.2. This source is located at a luminosity distance of 440_{-190}^{+180}  Mpc corresponding to a redshift of 0.09_{-0.04}^{+0.03}. All uncertainties define a 90% credible interval. This second gravitational-wave observation provides improved constraints on stellar populations and on deviations from general relativity.

  9. Probing Cloud-Driven Variability on Two of the Youngest, Lowest-Mass Brown Dwarfs in the Solar Neighborhood

    NASA Astrophysics Data System (ADS)

    Schneider, Adam; Cushing, Michael; Kirkpatrick, J. Davy

    2016-08-01

    Young, late-type brown dwarfs share many properties with directly imaged giant extrasolar planets. They therefore provide unique testbeds for investigating the physical conditions present in this critical temperature and mass regime. WISEA 1147-2040 and 2MASS 1119-1137, two recently discovered late-type (~L7) brown dwarfs, have both been determined to be members of the ~10 Myr old TW Hya Association (Kellogg et al. 2016, Schneider et al. 2016). Each has an estimated mass of 5-6 MJup, making them two of the youngest and lowest-mass free floating objects yet found in the solar neighborhood. As such, these two planetary mass objects provide unparalleled laboratories for investigating giant planet-like atmospheres far from the contaminating starlight of a host sun. Condensate clouds play a critical role in shaping the emergent spectra of both brown dwarfs and gas giant planets, and can cause photometric variability via their non-uniform spatial distribution. We propose to photometrically monitor WISEA 1147-2040 and 2MASS 1119-1137 in order to search for the presence of cloud-driven variability to 1) investigate the potential trend of low surface gravity with high-amplitude variability in a previously unexplored mass regime and 2) explore the angular momentum evolution of isolated planetary mass objects.

  10. Signatures Of A Putative Planetary Mass Solar Companion On The Orbital Distribution Of Tno's And Centaurs

    NASA Astrophysics Data System (ADS)

    Gomes, Rodney S.; Soares, J. S.

    2012-05-01

    Gomes et al. 2006 (Icarus 184, 589) show that a planetary mass solar companion (PMSC) can produce orbits in an inner Oort cloud that can account for Sedna's orbit. On the other hand, one should expect that this faraway planet would also produce some peculiar orbital distribution for distant TNO's and Centaurs. A pair of interesting orbits in this respect are those of 2006 SQ372 and 2000 OO67. These objects have very large semimajor axes and perihelion between Uranus and Neptune orbits. It has been claimed that a likely source for 2006 SQ372 is the Oort cloud. Yet a PMSC has an important effect on objects at inner Oort cloud distances, say between 300 AU and 2000 AU, to make their perihelion distances to continually oscillate with a large enough amplitude to account for objects both inside and outside Neptune's orbit. This naturally produces an extra amount of TNO's with semimajor axes between 300 and 2000 AU and perihelion inside Neptune's orbit, like 2006 SQ372 and 2000 OO67. This signature should be found in present observations. To deal with this problem we construct a numerical simulator and apply it to populations of distant TNO's produced by numerical integration of planetesimals and planets according to the Nice model, either including or not a PMSC. With the results from the numerical simulator we compare the model with and without the PMSC with observations. We conclude that a PMSC is compatible with the existence of 2006 SQ372 and 2000 OO67 and, in fact, although not conclusively, we can also claim that the observations of 2006 SQ372 and 2000 OO67, compared to all other scattered objects, would be lucky events if no PMSC exists.

  11. PLASMA HEATING DURING A CORONAL MASS EJECTION OBSERVED BY THE SOLAR AND HELIOSPHERIC OBSERVATORY

    SciTech Connect

    Murphy, N. A.; Raymond, J. C.; Korreck, K. E.

    2011-07-01

    We perform a time-dependent ionization analysis to constrain plasma heating requirements during a fast partial halo coronal mass ejection (CME) observed on 2000 June 28 by the Ultraviolet Coronagraph Spectrometer (UVCS) aboard the Solar and Heliospheric Observatory (SOHO). We use two methods to derive densities from the UVCS measurements, including a density sensitive O V line ratio at 1213.85 and 1218.35 A, and radiative pumping of the O VI {lambda}{lambda}1032, 1038 doublet by chromospheric emission lines. The most strongly constrained feature shows cumulative plasma heating comparable to or greater than the kinetic energy, while features observed earlier during the event show plasma heating of order or less than the kinetic energy. SOHO Michelson Doppler Imager observations are used to estimate the active region magnetic energy. We consider candidate plasma heating mechanisms and provide constraints when possible. Because this CME was associated with a relatively weak flare, the contribution from flare energy (e.g., through thermal conduction or energetic particles) is probably small; however, the flare may have been partially behind the limb. Wave heating by photospheric motions requires heating rates to be significantly larger than those previously inferred for coronal holes, but the eruption itself could drive waves that heat the plasma. Heating by small-scale reconnection in the flux rope or by the CME current sheet is not significantly constrained. UVCS line widths suggest that turbulence must be replenished continually and dissipated on timescales shorter than the propagation time in order to be an intermediate step in CME heating.

  12. ASYMMETRIC MAGNETIC RECONNECTION IN SOLAR FLARE AND CORONAL MASS EJECTION CURRENT SHEETS

    SciTech Connect

    Murphy, N. A.; Miralles, M. P.; Pope, C. L.; Raymond, J. C.; Winter, H. D.; Reeves, K. K.; Van Ballegooijen, A. A.; Lin, J.; Seaton, D. B.

    2012-05-20

    We present two-dimensional resistive magnetohydrodynamic simulations of line-tied asymmetric magnetic reconnection in the context of solar flare and coronal mass ejection current sheets. The reconnection process is made asymmetric along the inflow direction by allowing the initial upstream magnetic field strengths and densities to differ, and along the outflow direction by placing the initial perturbation near a conducting wall boundary that represents the photosphere. When the upstream magnetic fields are asymmetric, the post-flare loop structure is distorted into a characteristic skewed candle flame shape. The simulations can thus be used to provide constraints on the reconnection asymmetry in post-flare loops. More hard X-ray emission is expected to occur at the footpoint on the weak magnetic field side because energetic particles are more likely to escape the magnetic mirror there than at the strong magnetic field footpoint. The footpoint on the weak magnetic field side is predicted to move more quickly because of the requirement in two dimensions that equal amounts of flux must be reconnected from each upstream region. The X-line drifts away from the conducting wall in all simulations with asymmetric outflow and into the strong magnetic field region during most of the simulations with asymmetric inflow. There is net plasma flow across the X-line for both the inflow and outflow directions. The reconnection exhaust directed away from the obstructing wall is significantly faster than the exhaust directed toward it. The asymmetric inflow condition allows net vorticity in the rising outflow plasmoid which would appear as rolling motions about the flux rope axis.

  13. Comparing Spatial Distributions of Solar Prominence Mass Derived from Coronal Absorption

    NASA Technical Reports Server (NTRS)

    Gilbert, Holly; Kilper, Gary; Alexander, David; Kucera, Therese

    2010-01-01

    In the present work we extend the use of this mass-inference technique to a sample of prominences observed in at least two coronal lines. This approach, in theory, allows a direct calculation of prominence mass and helium abundance and how these properties vary spatially and temporally. Our motivation is two-fold: to obtain a He(exp 0)/H(exp 0) abundance ratio, and to determine how the relative spatial distribution of the two species varies in prominences. The first of these relies on the theoretical expectation that the amount of absorption at each EUV wavelength is well-characterized. However, in this work we show that due to a saturation of the continuum absorption in the 625 A and 368 A lines (which have much higher opacity compared to 195 A-) the uncertainties in obtaining the relative abundances are too high to give meaningful estimates. This is an important finding because of its impact on future studies in this area. The comparison of the spatial distribution of helium and hydrogen presented here augments previous observational work indicating that cross-field diffusion of neutrals is an important mechanism for mass loss. Significantly different loss timescales for neutral He and H (helium drains much more rapidly than hydrogen) can impact prominence structure, and both the present and past studies suggest this mechanism is playing a role in structure and possibly dynamics. Section 2 of this paper contains a description of the observations and Section 3 summarizes the method used to infer mass along with the criteria imposed in choosing prominences appropriate for this study. Section 3 also contains a discussion of the problems due to limitations of the available data and the implications for determining relative abundances. We present our results in Section 4, including plots of radial-like scans of prominence mass in different lines to show the spatial distribution of the different species. The last section contains a discussion summarizing the importance

  14. New improved reconstruction of solar activity over 3 millennia: Evidence for distinct solar dynamo modes

    NASA Astrophysics Data System (ADS)

    Usoskin, Ilya; Kovaltsov, Gennady; Hulot, Gauthier.; Gallet, Yves; Roth, Raphael; Licht, Alexis; Joos, Fortunat; Th, E.; Khokhlov, A.; Kovaltsov, Gennady A.

    The solar magnetic dynamo can operate in distinct modes - a main general mode, a Grand minimum mode corresponding to an inactive Sun, and a possible Grand maximum mode corresponding to an unusually active Sun, as e.g., observed recently. The reality of such mode separation has recently been the subject of much debate, with different theoretical speculations discussed. Here we present the first adjustment-free physical reconstruction of solar activity over the past three millennia, using the latest carbon cycle, (14) C production and archeomagnetic field models. This new improved reconstruction shows that the solar dynamo process indeed switches between different modes, either corresponding to different regimes of the dynamo or to changes in the driving parameters. These results provide important constraints for both dynamo models of Sun-like stars and investigations of possible solar influence on Earth’s climate.

  15. Catalyzing Mass Production of Solar Photovoltaic Cells Using University Driven Green Purchasing

    ERIC Educational Resources Information Center

    Pearce, Joshua M.

    2006-01-01

    Purpose: The purpose of this paper is to explore the use of the purchase power of the higher education system to catalyze the economy of scale necessary to ensure market competitiveness for solar photovoltaic electricity. Design/methodology/approach: The approach used here was to first determine the demand necessary to construct "Solar City…

  16. Study of Relationship Between Coronal Mass Ejections and the Electron Component of Solar Energetic Particles

    DTIC Science & Technology

    1995-01-01

    distance to another one it’s necessary to employ some model notions. We used ideas of elementary diffusion model (for example, [Lin et al,1982]) and took...Solar Physics (Moscow, Dec. 6-8, 1995). Detailled paper for ", Astrophisical Journal" or "Solar Physics", is on preparation now. Acknowledgements. 19 We

  17. ISEE-3 measurements of solar energetic particle composition

    NASA Astrophysics Data System (ADS)

    von Rosenvinge, T. T.; Reames, D. V.

    1980-10-01

    Preliminary observations of energetic particles from solar flares beginning on September 23 and November 10, 1978 are reported. The measurements were made from the ISEE-3 spacecraft using very thin, large area solid-state detectors. Charge composition was measured for all elements from Z = 2 to Z = 26 above approximately 2 MeV/nucleon. More than 100,000 nuclei with Z greater than 2 were pulse-height analyzed during the course of the first event, while the second was substantially smaller. These good statistics enable the observation of variations in composition at low energies as a function of time. For example, the Fe/O ratio (2.0-3.1 MeV/n) was observed in the September event to decrease by a factor of approximately 5. By contrast, this same ratio increased by a factor of approximately 1.5 during the November 10 event. Similar variations have been reported earlier by Scholer et al. (1978). These authors, however were unable to observe the He/O ratio which has now been observed also to show significant variation.

  18. Intermediate-mass Asymptotic Giant Branch Stars and Sources of 26Al, 60Fe, 107Pd, and 182Hf in the Solar System

    NASA Astrophysics Data System (ADS)

    Wasserburg, G. J.; Karakas, Amanda I.; Lugaro, Maria

    2017-02-01

    We explore the possibility that the short-lived radionuclides {}26{{A}}l, {}60{{F}}e, {}107{{P}}d, and {}182{{H}}f inferred to be present in the proto-solar cloud originated from 3–8 {M}ȯ asymptotic giant branch (AGB) stars. Models of AGB stars with initial mass above 5 {M}ȯ are prolific producers of {}26{{A}}l owing to hot bottom burning (HBB). In contrast, {}60{{F}}e, {}107{{P}}d, and {}182{{H}}f are produced by neutron captures: {}107{{P}}d and {}182{{H}}f in models ≲ 5 {M}ȯ , and {}60{{F}}e in models with higher mass. We mix stellar yields from solar-metallicity AGB models into a cloud of solar mass and composition to investigate whether it is possible to explain the abundances of the four radioactive nuclides at the Sun’s birth using one single value of the mixing ratio between the AGB yields and the initial cloud material. We find that AGB stars that experience efficient HBB (≥slant 6 {M}ȯ ) cannot provide a solution because they produce too little {}182{{H}}f and {}107{{P}}d relative to {}26{{A}}l and {}60{{F}}e. Lower-mass AGB stars cannot provide a solution because they produce too little {}26{{A}}l relative to {}107{{P}}d and {}182{{H}}f. A self-consistent solution may be found for AGB stars with masses in between (4–5.5 {M}ȯ ), provided that HBB is stronger than in our models and the {}13{{C}}(α, n){}16{{O}} neutron source is mildly activated. If stars of {{M}}< 5.5 {M}ȯ are the source of the radioactive nuclides, then some basis for their existence in proto-solar clouds needs to be explored, given that the stellar lifetimes are longer than the molecular cloud lifetimes.

  19. Dynamic Growth of Pinhole-Free Conformal CH3NH3PbI3 Film for Perovskite Solar Cells.

    PubMed

    Li, Bo; Tian, Jianjun; Guo, Lixue; Fei, Chengbin; Shen, Ting; Qu, Xuanhui; Cao, Guozhong

    2016-02-01

    Two-step dipping is one of the popular low temperature solution methods to prepare organic-inorganic halide perovskite (CH3NH3PbI3) films for solar cells. However, pinholes in perovskite films fabricated by the static growth method (SGM) result in low power conversion efficiency (PCE) in the resulting solar cells. In this work, the static dipping process is changed into a dynamic dipping process by controlled stirring PbI2 substrates in CH3NH3I isopropanol solution. The dynamic growth method (DGM) produces more nuclei and decreases the pinholes during the nucleation and growth of perovskite crystals. The compact perovskite films with free pinholes are obtained by DGM, which present that the big perovskite particles with a size of 350 nm are surrounded by small perovskite particles with a size of 50 nm. The surface coverage of the perovskite film is up to nearly 100%. Such high quality perovskite film not only eliminated pinholes, resulting in reduced charge recombination of the solar cells, but also improves the light harvesting efficiency. As a result, the PCE of the perovskite solar cells is increased from 11% for SGM to 13% for DGM.

  20. Large dielectric constant, high acceptor density, and deep electron traps in perovskite solar cell material CsGeI3

    DOE PAGES

    Ming, Wenmei; Shi, Hongliang; Du, Mao-Hua

    2016-01-01

    Here we report that many metal halides that contain cations with the ns2 electronic configuration have recently been discovered as high-performance optoelectronic materials. In particular, solar cells based on lead halide perovskites have shown great promise as evidenced by the rapid increase of the power conversion efficiency. In this paper, we show density functional theory calculations of electronic structure and dielectric and defect properties of CsGeI3 (a lead-free halide perovskite material). The potential of CsGeI3 as a solar cell material is assessed based on its intrinsic properties. We find anomalously large Born effective charges and a large static dielectric constantmore » dominated by lattice polarization, which should reduce carrier scattering, trapping, and recombination by screening charged defects and impurities. Defect calculations show that CsGeI3 is a p-type semiconductor and its hole density can be modified by varying the chemical potentials of the constituent elements. Despite the reduction of long-range Coulomb attraction by strong screening, the iodine vacancy in CsGeI3 is found to be a deep electron trap due to the short-range potential, i.e., strong Ge–Ge covalent bonding, which should limit electron transport efficiency in p-type CsGeI3. This is in contrast to the shallow iodine vacancies found in several Pb and Sn halide perovskites (e.g., CH3NH3PbI3, CH3NH3SnI3, and CsSnI3). The low-hole-density CsGeI3 may be a useful solar absorber material but the presence of the low-energy deep iodine vacancy may significantly reduce the open circuit voltage of the solar cell. Still, on the other hand, CsGeI3 may be used as an efficient hole transport material in solar cells due to its small hole effective mass, the absence of low-energy deep hole traps, and the favorable band offset with solar absorber materials such as dye molecules and CH3NH3PbI3.« less

  1. Systems efficiency and specific mass estimates for direct and indirect solar-pumped closed-cycle high-energy lasers in space

    NASA Technical Reports Server (NTRS)

    Monson, D. J.

    1978-01-01

    Based on expected advances in technology, the maximum system efficiency and minimum specific mass have been calculated for closed-cycle CO and CO2 electric-discharge lasers (EDL's) and a direct solar-pumped laser in space. The efficiency calculations take into account losses from excitation gas heating, ducting frictional and turning losses, and the compressor efficiency. The mass calculations include the power source, radiator, compressor, fluids, ducting, laser channel, optics, and heat exchanger for all of the systems; and in addition the power conditioner for the EDL's and a focusing mirror for the solar-pumped laser. The results show the major component masses in each system, show which is the lightest system, and provide the necessary criteria for solar-pumped lasers to be lighter than the EDL's. Finally, the masses are compared with results from other studies for a closed-cycle CO2 gasdynamic laser (GDL) and the proposed microwave satellite solar power station (SSPS).

  2. Isotopic mass fractionation laws for magnesium and their effects on 26Al-26Mg systematics in solar system materials

    NASA Astrophysics Data System (ADS)

    Davis, Andrew M.; Richter, Frank M.; Mendybaev, Ruslan A.; Janney, Philip E.; Wadhwa, Meenakshi; McKeegan, Kevin D.

    2015-06-01

    Magnesium isotope ratios are known to vary in solar system objects due to the effects of 26Al decay to 26Mg and mass-dependent fractionation, but anomalies of nucleosynthetic origin must also be considered. In order to infer the amount of enhancement of 26Mg/24Mg due to 26Al decay or to resolve small nucleogenetic anomalies, the exact relationship between 26Mg/24Mg and 25Mg/24Mg ratios due to mass-dependent fractionation, the mass-fractionation "law", must be accurately known so that the 25Mg/24Mg ratio can be used to correct the 26Mg/24Mg ratio for mass fractionation. Mass-dependent fractionation in mass spectrometers is reasonably well characterized, but not necessarily fully understood. It follows a simple power fractionation law, sometimes referred to as the "exponential law". In contrast, mass fractionation in nature, in particular that due to high temperature evaporation that likely caused the relatively large effects observed in calcium-, aluminum-rich inclusions (CAIs), is reasonably well understood, but mass-fractionation laws for magnesium have not been explored in detail. The magnesium isotopic compositions of CAI-like evaporation residues produced in a vacuum furnace indicate that the slope on a log 25Mg/24Mg vs. log 26Mg/24Mg plot is ∼0.5128, and different from those predicted by any of the commonly used mass-fractionation laws. Evaporation experiments on forsterite-rich bulk compositions give exactly the same slope, indicating that the measured mass-fractionation law for evaporation of magnesium is applicable to a wide range of bulk compositions. We discuss mass-fractionation laws and the implications of the measured fractionation behavior of magnesium isotopes for 26Al-26Mg chronology.

  3. Photocarrier recombination dynamics in perovskite CH3NH3PbI3 for solar cell applications.

    PubMed

    Yamada, Yasuhiro; Nakamura, Toru; Endo, Masaru; Wakamiya, Atsushi; Kanemitsu, Yoshihiko

    2014-08-20

    Using time-resolved photoluminescence and transient absorption measurements at room temperature, we report excitation-intensity-dependent photocarrier recombination processes in thin films made from the organo-metal halide perovskite semiconductor CH3NH3PbI3 for solar-cell applications. The photocarrier dynamics are well described by a simple rate equation including single-carrier trapping and electron-hole radiative recombination. This result provides clear evidence that the free-carrier model is better than the exciton model for interpreting the optical properties of CH3NH3PbI3. The observed large two-carrier recombination rate suggests the promising potential of perovskite semiconductors for optoelectronic device applications. Our findings provide the information about the dynamical behaviors of photoexcited carriers that is needed for developing high-efficiency perovskite solar cells.

  4. The impact of helium on thermosphere mass density response to geomagnetic activity during the recent solar minimum

    NASA Astrophysics Data System (ADS)

    Thayer, J. P.; Liu, X.; Lei, J.; Pilinski, M.; Burns, A. G.

    2012-07-01

    High-resolution mass density observations inferred from accelerometer measurements on the CHAMP and GRACE satellites are employed to investigate the thermosphere mass density response with latitude and altitude to geomagnetic activity during the recent solar minimum. Coplanar orbital periods in February 2007 and December 2008 revealed the altitude and latitude response in thermosphere mass density for their respective winter hemispheres was influenced by the relative amount of helium and oxygen present. The CHAMP-to-GRACE (C/G) mass density ratio depends on two terms; the first proportional to the ratio of the mean molecular weight to temperature and the second proportional to the vertical gradient of the logarithmic mean molecular weight. For the relative levels of helium and oxygen in February 2007, the winter hemisphere C/G mass density response to geomagnetic activity, although similar to the summer hemisphere, was caused predominantly by changes in the vertical gradient of the logarithmic mean molecular weight. In December 2008, the significant presence of helium caused the mean molecular weight changes to exceed temperature changes in the winter hemisphere leading to an increase in the C/G ratio with increasing geomagnetic activity, in opposition to the decrease observed in the summer hemisphere that was caused primarily by temperature changes. The observed behavior is indicative of composition effects influencing the mass density response and the dynamic action of the oxygen to helium transition region in both latitude and altitude will lead to complex behaviors in the mass density at GRACE altitudes throughout the extended solar minimum from 2007 to 2010.

  5. Solvent-Mediated Crystallization of CH3NH3SnI3 Films for Heterojunction Depleted Perovskite Solar Cells.

    PubMed

    Hao, Feng; Stoumpos, Constantinos C; Guo, Peijun; Zhou, Nanjia; Marks, Tobin J; Chang, Robert P H; Kanatzidis, Mercouri G

    2015-09-09

    Organo-lead halide perovskite solar cells have gained enormous significance and have now achieved power conversion efficiencies of ∼20%. However, the potential toxicity of lead in these systems raises environmental concerns for widespread deployment. Here we investigate solvent effects on the crystallization of the lead-free methylammonium tin triiodide (CH3NH3SnI3) perovskite films in a solution growth process. Highly uniform, pinhole-free perovskite films are obtained from a dimethyl sulfoxide (DMSO) solution via a transitional SnI2·3DMSO intermediate phase. This high-quality perovskite film enables the realization of heterojunction depleted solar cells based on mesoporous TiO2 layer but in the absence of any hole-transporting material with an unprecedented photocurrent up to 21 mA cm(-2). Charge extraction and transient photovoltage decay measurements reveal high carrier densities in the CH3NH3SnI3 perovskite device which are one order of magnitude larger than CH3NH3PbI3-based devices but with comparable recombination lifetimes in both devices. The relatively high background dark carrier density of the Sn-based perovskite is responsible for the lower photovoltaic efficiency in comparison to the Pb-based analogues. These results provide important progress toward achieving improved perovskite morphology control in realizing solution-processed highly efficient lead-free perovskite solar cells.

  6. Ionic polarization-induced current-voltage hysteresis in CH3NH3PbX3 perovskite solar cells

    NASA Astrophysics Data System (ADS)

    Meloni, Simone; Moehl, Thomas; Tress, Wolfgang; Franckevičius, Marius; Saliba, Michael; Lee, Yong Hui; Gao, Peng; Nazeeruddin, Mohammad Khaja; Zakeeruddin, Shaik Mohammed; Rothlisberger, Ursula; Graetzel, Michael

    2016-02-01

    CH3NH3PbX3 (MAPbX3) perovskites have attracted considerable attention as absorber materials for solar light harvesting, reaching solar to power conversion efficiencies above 20%. In spite of the rapid evolution of the efficiencies, the understanding of basic properties of these semiconductors is still ongoing. One phenomenon with so far unclear origin is the so-called hysteresis in the current-voltage characteristics of these solar cells. Here we investigate the origin of this phenomenon with a combined experimental and computational approach. Experimentally the activation energy for the hysteretic process is determined and compared with the computational results. First-principles simulations show that the timescale for MA+ rotation excludes a MA-related ferroelectric effect as possible origin for the observed hysteresis. On the other hand, the computationally determined activation energies for halide ion (vacancy) migration are in excellent agreement with the experimentally determined values, suggesting that the migration of this species causes the observed hysteretic behaviour of these solar cells.

  7. Ionic polarization-induced current–voltage hysteresis in CH3NH3PbX3 perovskite solar cells

    PubMed Central

    Meloni, Simone; Moehl, Thomas; Tress, Wolfgang; Franckevičius, Marius; Saliba, Michael; Lee, Yong Hui; Gao, Peng; Nazeeruddin, Mohammad Khaja; Zakeeruddin, Shaik Mohammed; Rothlisberger, Ursula; Graetzel, Michael

    2016-01-01

    CH3NH3PbX3 (MAPbX3) perovskites have attracted considerable attention as absorber materials for solar light harvesting, reaching solar to power conversion efficiencies above 20%. In spite of the rapid evolution of the efficiencies, the understanding of basic properties of these semiconductors is still ongoing. One phenomenon with so far unclear origin is the so-called hysteresis in the current–voltage characteristics of these solar cells. Here we investigate the origin of this phenomenon with a combined experimental and computational approach. Experimentally the activation energy for the hysteretic process is determined and compared with the computational results. First-principles simulations show that the timescale for MA+ rotation excludes a MA-related ferroelectric effect as possible origin for the observed hysteresis. On the other hand, the computationally determined activation energies for halide ion (vacancy) migration are in excellent agreement with the experimentally determined values, suggesting that the migration of this species causes the observed hysteretic behaviour of these solar cells. PMID:26852685

  8. Ionic polarization-induced current-voltage hysteresis in CH3NH3PbX3 perovskite solar cells.

    PubMed

    Meloni, Simone; Moehl, Thomas; Tress, Wolfgang; Franckevičius, Marius; Saliba, Michael; Lee, Yong Hui; Gao, Peng; Nazeeruddin, Mohammad Khaja; Zakeeruddin, Shaik Mohammed; Rothlisberger, Ursula; Graetzel, Michael

    2016-02-08

    CH3NH3PbX3 (MAPbX3) perovskites have attracted considerable attention as absorber materials for solar light harvesting, reaching solar to power conversion efficiencies above 20%. In spite of the rapid evolution of the efficiencies, the understanding of basic properties of these semiconductors is still ongoing. One phenomenon with so far unclear origin is the so-called hysteresis in the current-voltage characteristics of these solar cells. Here we investigate the origin of this phenomenon with a combined experimental and computational approach. Experimentally the activation energy for the hysteretic process is determined and compared with the computational results. First-principles simulations show that the timescale for MA(+) rotation excludes a MA-related ferroelectric effect as possible origin for the observed hysteresis. On the other hand, the computationally determined activation energies for halide ion (vacancy) migration are in excellent agreement with the experimentally determined values, suggesting that the migration of this species causes the observed hysteretic behaviour of these solar cells.

  9. Application of Y(2)O(3):Er(3+) nanorods in dye-sensitized solar cells.

    PubMed

    Wang, Jiangli; Wu, Jihuai; Lin, Jianming; Huang, Miaoliang; Huang, Yunfang; Lan, Zhang; Xiao, Yaoming; Yue, Gentian; Yin, Shu; Sato, Tsugio

    2012-07-01

    Y(2)O(3):Er(3+) nanorods are synthesized by means of a hydrothermal method and then introduced into a TiO(2) electrode in a dye-sensitized solar cell (DSSC). Y(2)O(3):Er(3+) improves infrared light harvest via up-conversion luminescence and increases the photocurrent of the DSSC. The rare earth ions improve the energy level of the TiO(2) electrode through a doping effect and thus increase the photovoltage. The light scattering is ameliorated by the one-dimensional nanorod structure. The DSSC containing Y(2)O(3):Er(3+) (5 wt%) in the doping layer achieves a light-to-electric energy conversion efficiency of 7.0%, which is an increase of 19.9% compared to the DSSC lacking of Y(2)O(3):Er(3+).

  10. Optimization of solar cells for air mass zero operation and study of solar cells at high temperatures, phase 4

    NASA Technical Reports Server (NTRS)

    Hovel, H. J.; Woodall, J. M.

    1980-01-01

    The Pd contact to GaAs was studied using backscattering, Auger analysis, and sheet resistance measurements. Several metallurgical phases were present at low temperatures, but PdGa was the dominant phase in samples annealed at 500 C. Ti/Pd/Ag contacts appeared to have the lowest contact resistance. Etchback epitaxy (EBE) was compared to saturated melt epitaxy (SME) method of growing liquid phase epitaxial layers. The SME method resulted in a lower density of Ga microdroplets in the grown layer, although the best solar cells were made by the EBE method. Photoluminescence was developed as a tool for contactless analysis of GaAs cells. Efficiencies of over 8 percent were measured at 250 C.

  11. Three-fluid, 3D MHD solar wind modeling with turbulence transport and eddy viscosity

    NASA Astrophysics Data System (ADS)

    Usmanov, A. V.; Goldstein, M. L.; Matthaeus, W. H.

    2014-12-01

    We present results from a three-fluid, fully three-dimensional MHD solar wind model that includes turbulence transport, eddy viscosity, turbulent resistivity, and turbulent heating. The solar wind plasma is described as a co-moving system of three species: the solar wind protons, electrons, and interstellar pickup protons. Separate energy equations are employed for each species. We obtain numerical solutions of Reynolds-averaged solar wind equations coupled with turbulence transport equations in the region from 0.3 to 100 AU. The integrated system of equations includes the effects of electron heat conduction, Coulomb collisions, photoionization of interstellar hydrogen atoms and their charge exchange with the solar wind protons, turbulence energy generation by pickup protons, and turbulent heating of solar wind protons and electrons. Using either a dipole approximation for the solar magnetic field or synoptic solar magnetograms from the Wilcox Solar Observatory for assigning boundary conditions at the coronal base, we apply the model to study the global structure of the solar wind and its three-dimensional properties, including turbulence parameters, throughout the heliosphere. The model results are compared with observations on WIND, Ulysses and Voyager 2 spacecraft. This work is partially supported by LWS and Heliophysics Grand Challenges programs.

  12. Near-Earth Interplanetary Coronal Mass Ejections During Solar Cycle 23 (1996 - 2009): Catalog and Summary of Properties

    NASA Technical Reports Server (NTRS)

    Richardson, I. G.; Cane, H. V.

    2010-01-01

    In a previous study (Cane and Richardson, J. Geophys. Res. l08(A4), SSH6-1, we investigated the occurrence of interplanetary coronal mass ejections in the near-Earth solar wind during 1996 - 2002, corresponding to the increasing and maximum phases of solar cycle 23, and provided a "comprehensive" catalog of these events. In this paper, we present a revised and updated catalog of the approx. =300 near-Earth ICMEs in 1996-2009, encompassing the complete cycle 23, and summarize their basic properties and geomagnetic effects. In particular, solar wind .. composition and charge state observations are now considered when identifying the ICMEs. In general, these additional data confirm the earlier identifications based predominantly on other solar wind plasma and magnetic field parameters. However, the boundaries of ICME-like plasma based on charge state/composition data may deviate significantly from those based on conventional plasma/magnetic field parameters. Furthermore, the much studied "magnetic clouds", with flux-rope-like magnetic field configurations, may form just a substructure of the total ICME interval.

  13. Height of Shock Formation in the Solar Corona Inferred from Observations of Type II Radio Bursts and Coronal Mass Ejections

    NASA Technical Reports Server (NTRS)

    Gopalswamy, N.; Xie, H.; Makela, P.; Yashiro, S.; Akiyama, S.; Uddin, W.; Srivastava, A. K.; Joshi, N. C.; Chandra, R.; Manoharan, P. K.

    2013-01-01

    Employing coronagraphic and EUV observations close to the solar surface made by the Solar Terrestrial Relations Observatory (STEREO) mission, we determined the heliocentric distance of coronal mass ejections (CMEs) at the starting time of associated metric type II bursts. We used the wave diameter and leading edge methods and measured the CME heights for a set of 32 metric type II bursts from solar cycle 24. We minimized the projection effects by making the measurements from a view that is roughly orthogonal to the direction of the ejection. We also chose image frames close to the onset times of the type II bursts, so no extrapolation was necessary. We found that the CMEs were located in the heliocentric distance range from 1.20 to 1.93 solar radii (Rs), with mean and median values of 1.43 and 1.38 Rs, respectively. We conclusively find that the shock formation can occur at heights substantially below 1.5 Rs. In a few cases, the CME height at type II onset was close to 2 Rs. In these cases, the starting frequency of the type II bursts was very low, in the range 25-40 MHz, which confirms that the shock can also form at larger heights. The starting frequencies of metric type II bursts have a weak correlation with the measured CME/shock heights and are consistent with the rapid decline of density with height in the inner corona.

  14. Characterization of thin film tandem solar cells by radiofrequency pulsed glow discharge - Time of flight mass spectrometry.

    PubMed

    Fernandez, Beatriz; Lobo, Lara; Reininghaus, Nies; Pereiro, Rosario; Sanz-Medel, Alfredo

    2017-04-01

    Beside low production costs and the use of nontoxic and abundant raw materials, silicon based thin-film solar cells have the advantage to be built up as multi junction devices like tandem or triple junction solar cells. Silicon thin film modules made of tandem cells with hydrogenated amorphous silicon (a-Si:H) top cell and microcrystalline (μc) Si:H bottom cell are available on the market. In this work, the analytical potential of state-of-the art radiofrequency (rf) pulsed glow discharge (PGD) time of flight mass spectrometry (TOFMS) commercial instrumentation is investigated for depth profiling analysis of tandem-junctions solar cells on 2mm thick glass substrate with 1µm thick ZnO:Al. Depth profile characterization of two thin film tandem photovoltaic devices was compared using millisecond and sub-millisecond rf-PGD regimes, as well as the so-called "low mass mode" available in the commercial instrument used. Two procedures for sample preparation, namely using flat or rough cell substrates, were compared and the distribution of dopant elements (phosphorous, boron and germanium) was investigated in both cases. Experimental results obtained by rf-PGD-TOFMS as well as electrical measurements of the samples showed that a worse depth resolution of dopant elements in the silicon layers (e.g. distribution of boron in a thicker region that suggests a diffusion of this dopant in the coating of the sample) found using a rough sample substrate was related to a higher power conversion efficiency.

  15. Gravitational lensing of supernovae by dark matter candidates of mass M greater than about 0.001 solar masses

    NASA Technical Reports Server (NTRS)

    Wagoner, Robert V.; Linder, Eric V.

    1987-01-01

    A review is presented concerning the gravitational lensing of supernovae by intervening condensed objects, including dark matter candidates such as dim stars and black holes. the expansion of the supernova beam within the lens produces characteristic time-dependent amplification and polarization which depend upon the mass of the lens. The effects of the shearing of the beam due to surrounding masses are considered, although the study of these effects is confined to isolated masses whose size is much less than that of the supernova (about 10 to the 15th cm). Equations for the effects of lensing and graphs comparing these effects in different classes of supernovae are compared. It is found that candidates for lensing would be those supernovae at least as bright as their parent galaxy, or above the range of luminosities expected for their spectral class.

  16. EPA Enforcement Ensures that Solar Company Follows Stormwater Discharge Requirements at Warren, Mass. Facility

    EPA Pesticide Factsheets

    A settlement signed recently by a company that builds solar power facilities in Massachusetts will remind construction companies that the US Environmental Protection Agency continues to protect the environment from illegal discharges of sto

  17. Densities and mass motions in transition-zone plasmas in solar flares observed from Skylab

    NASA Technical Reports Server (NTRS)

    Cheng, C.-C.

    1980-01-01

    The electron densities and bulk motions in the transition-zone plasma of a solar flare are investigated by an analysis of EUV emission line spectra taken on Skylab. Spectra of three flares were obtained with the NRL normal incidence grating slit spectrograph in the ranges 1100-1940 and 1940-3940 A. The line ratios of transition-zone Si III lines and the intensity of the forbidden O IV 1401-A lines during flare maximum indicate electron densities on the order of 10 to the 12th/cu cm, decreasing by a factor of 2 to 3 in the flare decay phase. Line broadening of the transition-zone ions such as Si III, O IV, C IV and N V is noted, and the observed asymmetrical N V line profiles are approximated by a bi-Gaussian model of a stationary and a moving plasma component with a bulk velocity of 12 to 70 km/sec. Turbulent velocities of from 45 to 85 km/sec and from 20 to 40 km/sec are also indicated for the moving and stationary components of the transition-zone plasma, respectively.

  18. Onset of the Magnetic Explosion in Solar Flares and Coronal Mass Ejections

    NASA Technical Reports Server (NTRS)

    Moore, R. L.; Sterling, A. C.; Hudson, H.; Lemen, J. R.; Rose, M. Franklin (Technical Monitor)

    2000-01-01

    We present observations of the magnetic field configuration and its transformation in six solar eruptive events that show good agreement with the Hirayama-Shibata model for eruptive flares. The observations arc X-ray images from the Yohkoh Soft X-ray Telescope (SXT) and magnetograms from Kitt Peak National Solar Observatory, interpreted together with the 1-8 Angstrom X-ray flux observed by GOES. The observations show: 1. Each event is a magnetic explosion that occurs in an initially closed magnetic bipole in which the core field is sheared and twisted in the shape of a sigmoid, having an oppositely curved elbow on each end. The arms of the opposite elbows are sheared past each other so that they overlap and are crossed low above the neutral line in the middle of the bipole. 2. Although four of the explosions arc ejective (blow open the bipole) and two are confined (arc arrested within the closed bipole), all six begin the same way. In the SXT iniages, the explosion begins with brightening and expansion of the two elbows together with the appearance of short bright sheared loops low over the neutral line under the crossed arms and, rising up from the crossed arms, long strands connecting the far ends of the elbows. 3. All six events arc single-bipole events in that during the onset and early development of the explosion they show no evidence for reconnection between the exploding bipole and any surrounding magnetic fields. We conclude that in each of our events the magnetic explosion was unleashed by runaway tether-cutting via implosive/explosive rcconnection in the middle of the sigmoid, as in the Hirayama-Shibata model. The similarity of the onsets of the two confined explosions to the onsets of the four ejective explosions and their agreement with the model indicate that runaway reconnection inside a sheared core field can begin whether or not the overlying fields (the envelope field and contiguous fields that press down on the envelope) allow the explosion to be

  19. An ultraviolet responsive hybrid solar cell based on titania/poly(3-hexylthiophene)

    PubMed Central

    Wu, Jihuai; Yue, Gentian; Xiao, Yaoming; Lin, Jianming; Huang, Miaoliang; Lan, Zhang; Tang, Qunwei; Huang, Yunfang; Fan, Leqing; Yin, Shu; Sato, Tsugio

    2013-01-01

    Here we present an ultraviolet responsive inorganic-organic hybrid solar cell based on titania/poly(3-hexylthiophene) (TiO2/P3HT) heterojuction. In this solar cell, TiO2 is an ultraviolet light absorber and electronic conductor, P3HT is a hole conductor, the light-to-electrical conversion is realized by the cooperation for these two components. Doping ionic salt in P3HT polymer can improve the photovoltaic performance of the solar cell. Under ultraviolet light irradiation with intensity of 100 mW·cm−2, the hybrid solar cell doped with 1.0 wt.% lithium iodide achieves an energy conversion efficiency of 1.28%, which is increased by 33.3% compared to that of the hybrid solar cell without lithium iodide doping. Our results open a novel sunlight irradiation field for solar energy utilization, demonstrate the feasibility of ultraviolet responsive solar cells, and provide a new route for enhancing the photovoltaic performance of solar cells. PMID:23412470

  20. Revisiting the Microlensing Event OGLE 2012-BLG-0026: A Solar Mass Star with Two Cold Giant Planets

    NASA Technical Reports Server (NTRS)

    Beaulieu, J.-P.; Bennett, D. P.; Batista, V.; Fukui, A.; Marquette, J.-B.; Brillant, S.; Cole, A. A.; Rogers, L. A.; Sumi, T.; Abe, F.

    2016-01-01

    Two cold gas giant planets orbiting a G-type main-sequence star in the galactic disk were previously discovered in the high-magnification microlensing event OGLE-2012-BLG-0026. Here, we present revised host star flux measurements and a refined model for the two-planet system using additional light curve data. We performed high angular resolution adaptive optics imaging with the Keck and Subaru telescopes at two epochs while the source star was still amplified. We detected the lens flux, H = 16.39 +/- 0.08. The lens, a disk star, is brighter than predicted from the modeling in the original study. We revisited the light curve modeling using additional photometric data from the B and C telescope in New Zealand and CTIO 1.3 m H-band light curve. We then include the Keck and Subaru adaptive optic observation constraints. The system is composed of an approximately 4-9 Gyr lens star of M(sub lens) = 1.06 +/- 0.05 solar mass at a distance of D(sub lens) = 4.0 +/- 0.3 kpc, orbited by two giant planets of 0.145 +/- 0.008 M(sub Jup) and 0.86 +/- 0.06 M(sub Jup), with projected separations of 4.0 +/- 0.5 au and 4.8 +/- 0.7 au, respectively. Because the lens is brighter than the source star by 16 +/- 8% in H, with no other blend within one arcsec, it will be possible to estimate its metallicity using subsequent IR spectroscopy with 8-10 m class telescopes. By adding a constraint on the metallicity it will be possible to refine the age of the system.

  1. MeV He3/He4 isotope abundances in solar energetic particle events: SOHO/COSTEP observations

    NASA Astrophysics Data System (ADS)

    Bothmer, V.:; Sierks, H.; Böhm, E.; Kunow, H.

    2001-08-01

    We present first results based on a systematic survey of 4-41 MeV/N 3He/4He isotope abundances with ratios >0.01 detected by the COmprehensive SupraThermal and Energetic Particle analyzer (COSTEP) onboard the SOHO (SOlar and Heliospheric Observatory) spacecraft. More than about 25% of the identified events showed 3He/4He ratios in the range 0.1-1. For events with sufficiently high detector count rates the atomic mass plots can be resolved up to a time resolution of about 1 hour. These events are most suitable for comparisons with in situ solar wind plasma and magnetic field measurements and SOHO's optical white-light and extreme ultraviolet (EUV) observations of the Sun. The correlations show an association with passages of shock associated coronal mass ejections (CMEs) in the solar wind that inhibit high He/H plasma overabundances. It is likely that the CMEs have been released in strong magnetic reconfiguration processes at the solar source sites. Here we present a brief overview of such an event detected on October 30, 2000. 1. Introduction The SOHO/COSTEP instrument measures solar energetic particles (SEPs) at MeV energies in the interplanetary medium. The solid state detectors are capable to detect 3 He/4 He-enrichments at these energies (Müller-Mellin et al., 1995). Usually, the 3 He/4 He-ratio in the solar wind is at the order of 10-4 , but occasionally ratios up to about values of ~1 or even above have been observed in SEP events (e.g., Mason et al., 1999). The origin of these isotope abundances has commonly been attributed to impulsive solar flares and wave-particle interaction mechanisms (Temerin and Roth, 1992). However, fully satisfying physical explanations are still lacking. Here we present first results of a systematic survey of the He-measurements taken by COSTEP since launch in 1995 until the end of the year 2000. 2. Data For this study we have analyzed SOHO/COSTEP measurements of 4.3-40.9 MeV/N helium particles as well as COSTEP data covering

  2. Effect of solvent annealing on heterojunction polymer solar cells based on P3HT/PCBM.

    PubMed

    Park, Hanok; Ambade, Rohan B; Lee, Soo-Hyoung

    2013-12-01

    Heterojunction (HJ) structure has the advantages of high charge collection and transport efficiency, but it also has the disadvantage of low charge collection, due to limited p-n interfaces, compared with bulkheterojunction (BHJ) structure. In order to overcome this disadvantage of HJ, we fabricated HJ solar cells with large p-n interfaces, based on poly(3-hexylthiophene) (P3HT)/[6,6]-phenyl-C61-butylric acid methyl ester (PC61 BM), treated by a solvent annealing (SA) process under atmospheric condition, which is a simple and low-cost process. The SA process induced a P3HT-PC61 BM interdiffusion layer between the P3HT and PC61 BM layers, by a diffusion of each component, and resulted in an increase of p-n interface areas. These results were confirmed by X-ray photoelectron spectroscopy (XPS), and time-of-flight secondary ion mass spectroscopy (ToF-SIMS). The performance of a HJ device fabricated with a SA process achieved a 30% higher power conversion efficiency (PCE) value (approximately 3.3%), than that without a SA process. Interestingly, the HJ SA device showed higher long-term stability, than that without a SA process.

  3. A solar type II radio burst from coronal mass ejection-coronal ray interaction: Simultaneous radio and extreme ultraviolet imaging

    SciTech Connect

    Chen, Yao; Du, Guohui; Feng, Shiwei; Kong, Xiangliang; Wang, Bing; Feng, Li; Guo, Fan; Li, Gang

    2014-05-20

    Simultaneous radio and extreme ultraviolet (EUV)/white-light imaging data are examined for a solar type II radio burst occurring on 2010 March 18 to deduce its source location. Using a bow-shock model, we reconstruct the three-dimensional EUV wave front (presumably the type-II-emitting shock) based on the imaging data of the two Solar TErrestrial RElations Observatory spacecraft. It is then combined with the Nançay radio imaging data to infer the three-dimensional position of the type II source. It is found that the type II source coincides with the interface between the coronal mass ejection (CME) EUV wave front and a nearby coronal ray structure, providing evidence that the type II emission is physically related to the CME-ray interaction. This result, consistent with those of previous studies, is based on simultaneous radio and EUV imaging data for the first time.

  4. 2 kWe Solar Dynamic Ground Test Demonstration Project. Volume 3; Fabrication and Test Report

    NASA Technical Reports Server (NTRS)

    Alexander, Dennis

    1997-01-01

    The Solar Dynamic Ground Test Demonstration (SDGTD) project has successfully designed and fabricated a complete solar-powered closed Brayton electrical power generation system and tested it in a relevant thermal vacuum facility at NASA Lewis Research Center (LeRC). In addition to completing technical objectives, the project was completed 3-l/2 months early, and under budget.

  5. Heliocentric Distance of Coronal Mass Ejections at the Time of Energetic Particle Release: Revisiting the Ground Level Enhancement Events of Solar Cycle 23

    NASA Technical Reports Server (NTRS)

    Gopalswamy, Natchimuthuk

    2011-01-01

    Using the kinematics of coronal mass ejections (CMEs), onset time of soft X-ray flares, and the finite size of the pre-eruption CME structure, we derive the heliocentric distane at which the energetic particles during the ground level enhancement (GLE) events of Solar Cycle 23. We find that the GLE particles are released when the CMEs reach an average heliocentric distance of approx.3.25 solar radii (Rs). From this we infer that the shocks accelerating the particles are located at similar heights. Type II radio burst observations indicate that the CMEs are at much lower distances (average approx.1.4 Rs) when the CME-driven shock first forms. The shock seems to travel approx.1.8 Rs over a period of approox.30 min on the average before releasing the GLE particles. In deriving these results, we made three assumptions that have observational support: (i) the CME lift off occurs from an initial distance of about 1.25 Rs; (ii) the flare onset and CME onset are one and the same because these are two different manifestations of the same eruption; and (iii) the CME has positive acceleration from the onset to the first appearance in the coronagraphic field of view (2.5 to 6 Rs). Observations of coronal cavities in eclipse pictures and in coronagraphic images justify the assumption (i). The close relationship between the flare reconnection magnetic flux and the azimuthal flux of interplanetary magnetic clouds justify assumption (ii) consistent with the standard model (CSHKP) of solar eruption. Coronagraphic observations made close to the solar surface indicate a large positive acceleration of CMEs to a heliocentric distance of approx.3 Rs before they start slowing down due to the drag force. The inferred acceleration (approx.1.5 km/s/s) is consistent with reported values in the literature.

  6. Workshop on Solar Activity, Solar Wind, Terrestrial Effects, and Solar Acceleration

    NASA Technical Reports Server (NTRS)

    1992-01-01

    A summary of the proceedings from the workshop are presented. The areas covered were solar activity, solar wind, terrestrial effects, and solar acceleration. Specific topics addressed include: (1) solar cycle manifestations, both large and small scale, as well as long-term and short-term changes, including transients such as flares; (2) sources of solar wind, as identified by interplanetary observations including coronal mass ejections (CME's) or x-ray bright points, and the theory for and evolution of large-scale and small-scale structures; (3) magnetosphere responses, as observed by spacecraft, to variable solar wind and transient energetic particle emissions; and (4) origin and propagation of solar cosmic rays as related to solar activity and terrestrial effects, and solar wind coronal-hole relationships and dynamics.

  7. The Width of a Solar Coronal Mass Ejection and the Source of the Driving Magnetic Explosion

    NASA Technical Reports Server (NTRS)

    Moore, Ronald L.; Sterling, Alphonse C.; Suess, Steven T.

    2007-01-01

    We show that the strength of the magnetic field in the area covered by the flare arcade following a CME-producing ejective solar eruption can be estimated from the final angular width of the CME in the outer corona and the final angular width of the flare arcade. We assume (1) the flux-rope plasmoid ejected from the flare site becomes the interior of the CME plasmoid, (2) in the outer corona (R greater than 2R(sub Sun)) the CME is roughly a spherical plasmoid with legs shaped like a light bulb, and (3) beyond some height in or below the outer corona the CME plasmoid is in lateral pressure balance with the surrounding magnetic field. The strength of the nearly radial magnetic field in the outer corona is estimated from the radial component of the interplanetary magnetic field measured by Ulysses. We apply this model to three well-observed CMEs that exploded from flare regions of extremely different size and magnetic setting. One of these CMEs is an over-and-out CME that exploded from a laterally far offset compact ejective flare. In each event, the estimated source-region field strength is appropriate for the magnetic setting of the flare. This agreement (1) indicates that CMEs are propelled by the magnetic field of the CME plasmoid pushing against the surrounding magnetic field, (2) supports the magnetic-arch-blowout scenario for over-and-out CMEs, and (3) shows that a CME s final angular width in the outer corona can be estimated from the amount of magnetic flux covered by the source-region flare arcade.

  8. Very Low Mass Stellar and Substellar Companions to Solar-like Stars from MARVELS. IV. A Candidate Brown Dwarf or Low-mass Stellar Companion to HIP 67526

    NASA Astrophysics Data System (ADS)

    Jiang, Peng; Ge, Jian; Cargile, Phillip; Crepp, Justin R.; De Lee, Nathan; Porto de Mello, Gustavo F.; Esposito, Massimiliano; Ferreira, Letícia D.; Femenia, Bruno; Fleming, Scott W.; Gaudi, B. Scott; Ghezzi, Luan; González Hernández, Jonay I.; Hebb, Leslie; Lee, Brian L.; Ma, Bo; Stassun, Keivan G.; Wang, Ji; Wisniewski, John P.; Agol, Eric; Bizyaev, Dmitry; Brewington, Howard; Chang, Liang; Nicolaci da Costa, Luiz; Eastman, Jason D.; Ebelke, Garrett; Gary, Bruce; Kane, Stephen R.; Li, Rui; Liu, Jian; Mahadevan, Suvrath; Maia, Marcio A. G.; Malanushenko, Viktor; Malanushenko, Elena; Muna, Demitri; Nguyen, Duy Cuong; Ogando, Ricardo L. C.; Oravetz, Audrey; Oravetz, Daniel; Pan, Kaike; Pepper, Joshua; Paegert, Martin; Allende Prieto, Carlos; Rebolo, Rafael; Santiago, Basilio X.; Schneider, Donald P.; Shelden Bradley, Alaina C.; Sivarani, Thirupathi; Snedden, Stephanie; van Eyken, J. C.; Wan, Xiaoke; Weaver, Benjamin A.; Zhao, Bo

    2013-09-01

    We report the discovery of a candidate brown dwarf (BD) or a very low mass stellar companion (MARVELS-5b) to the star HIP 67526 from the Multi-object Apache point observatory Radial Velocity Exoplanet Large-area Survey (MARVELS). The radial velocity curve for this object contains 31 epochs spread over 2.5 yr. Our Keplerian fit, using a Markov Chain Monte Carlo approach, reveals that the companion has an orbital period of 90.2695^{+0.0188}_{-0.0187} days, an eccentricity of 0.4375 ± 0.0040, and a semi-amplitude of 2948.14^{+16.65}_{-16.55} m s-1. Using additional high-resolution spectroscopy, we find the host star has an effective temperature T eff = 6004 ± 34 K, a surface gravity log g (cgs) =4.55 ± 0.17, and a metallicity [Fe/H] =+0.04 ± 0.06. The stellar mass and radius determined through the empirical relationship of Torres et al. yields 1.10 ± 0.09 M ⊙ and 0.92 ± 0.19 R ⊙. The minimum mass of MARVELS-5b is 65.0 ± 2.9M Jup, indicating that it is likely to be either a BD or a very low mass star, thus occupying a relatively sparsely populated region of the mass function of companions to solar-type stars. The distance to this system is 101 ± 10 pc from the astrometric measurements of Hipparcos. No stellar tertiary is detected in the high-contrast images taken by either FastCam lucky imaging or Keck adaptive optics imaging, ruling out any star with mass greater than 0.2 M ⊙ at a separation larger than 40 AU.

  9. VERY LOW MASS STELLAR AND SUBSTELLAR COMPANIONS TO SOLAR-LIKE STARS FROM MARVELS. IV. A CANDIDATE BROWN DWARF OR LOW-MASS STELLAR COMPANION TO HIP 67526

    SciTech Connect

    Jiang Peng; Ge Jian; De Lee, Nathan; Fleming, Scott W.; Lee, Brian L.; Ma Bo; Wang, Ji; Cargile, Phillip; Hebb, Leslie; Stassun, Keivan G.; Crepp, Justin R.; Porto de Mello, Gustavo F.; Ferreira, Leticia D.; Esposito, Massimiliano; Femenia, Bruno; Gonzalez Hernandez, Jonay I.; Ghezzi, Luan; Wisniewski, John P.; Agol, Eric; and others

    2013-09-15

    We report the discovery of a candidate brown dwarf (BD) or a very low mass stellar companion (MARVELS-5b) to the star HIP 67526 from the Multi-object Apache point observatory Radial Velocity Exoplanet Large-area Survey (MARVELS). The radial velocity curve for this object contains 31 epochs spread over 2.5 yr. Our Keplerian fit, using a Markov Chain Monte Carlo approach, reveals that the companion has an orbital period of 90.2695{sup +0.0188}{sub -0.0187} days, an eccentricity of 0.4375 {+-} 0.0040, and a semi-amplitude of 2948.14{sup +16.65}{sub -16.55} m s{sup -1}. Using additional high-resolution spectroscopy, we find the host star has an effective temperature T{sub eff} = 6004 {+-} 34 K, a surface gravity log g (cgs) =4.55 {+-} 0.17, and a metallicity [Fe/H] =+0.04 {+-} 0.06. The stellar mass and radius determined through the empirical relationship of Torres et al. yields 1.10 {+-} 0.09 M{sub Sun} and 0.92 {+-} 0.19 R{sub Sun }. The minimum mass of MARVELS-5b is 65.0 {+-} 2.9M{sub Jup}, indicating that it is likely to be either a BD or a very low mass star, thus occupying a relatively sparsely populated region of the mass function of companions to solar-type stars. The distance to this system is 101 {+-} 10 pc from the astrometric measurements of Hipparcos. No stellar tertiary is detected in the high-contrast images taken by either FastCam lucky imaging or Keck adaptive optics imaging, ruling out any star with mass greater than 0.2 M{sub Sun} at a separation larger than 40 AU.

  10. Solar Electromagnetic Radiation Study for Solar Cycle 22: Solar Ultraviolet Irradiance, 120 to 300 NM: Report of Working Groups 2 and 3 of SOLERS 22

    NASA Technical Reports Server (NTRS)

    Rottman, G. J.; Cebula, R. P.; Gillotay, D.; Simon, P. A.

    1996-01-01

    This report summarizes the activities of Working Group 2 and Working Group 3 of the SOLax Electromagnetic Radiation Study for Solar Cycle 22 (SOLERS22) Program. The international (SOLERS22) is Project 1.2 of the Solar-Terrestrial Energy Program (STEP) sponsored by SCOSTEP, a committee of the International Council of Scientific Unions). SOLERS22 is comprised of five Working Groups, each concentrating on a specific wave-length range: WG-1 - visible and infrared, WG-2 - mid-ultraviolet (200 < A < 300 nm), WG-3 - Far-ultraviolet (lambda greater than 100 and lambda less than 200 nanometers), WG-4 - extreme-ultraviolet (lambda greater than 10 and lambda less than 100 nm), and WG-5 - X-ray (lambda greater than 1 and lambda less than 10 nano meters). The overarching goals of SOLERS22 are to: 1) establish daily solar irradiance values in the specified wavelength ranges, 2) consider the evolving solar structures as the cause of temporal variations, and 3) understand the underlying physical processes driving these changes.

  11. A direct gravitational lensing test for 10 exp 6 solar masses black holes in halos of galaxies

    NASA Technical Reports Server (NTRS)

    Wambsganss, Joachim; Paczynski, Bohdan

    1992-01-01

    We propose a method that will be able to detect or exclude the existence of 10 exp 6 solar masses black holes in the halos of galaxies. VLBA radio maps of two milliarcsecond jets of a gravitationally lensed quasar will show the signature of these black holes - if they exist. If there are no compact objects in this mass range along the line of sight, the two jets should be linear mappings of each other. If they are not, there must be compact objects of about 10 exp 6 solar masses in the halo of the galaxy that deform the images by gravitational deflection. We present numerical simulations for the two jets A and B of the double quasar 0957 + 561, but the method is valid for any gravitationally lensed quasar with structure on milliarcsecond scales. As a by-product from high-quality VLBA maps of jets A and B, one will be able to tell which features in the maps are intrinsic in the original jet and which are only an optical illusion, i.e., gravitational distortions by black holes along the line of sight.

  12. Antireflective downconversion ZnO:Er3+,Yb3+ thin film for Si solar cell applications

    NASA Astrophysics Data System (ADS)

    Elleuch, R.; Salhi, R.; Deschanvres, J.-L.; Maalej, R.

    2015-02-01

    Hexagonal wurtzite phased ZnO:Er3+/Yb3+ thin films with various Yb concentrations were deposited on Si(111) substrate by Aerosol Assisted Chemical Vapor Deposition process. Post-annealed films at 1000 °C in air atmosphere showed a crystallinity enhancement. Yb3+ (4F7/2 → 4F5/2) 1000 nm emission increased with the increase of Yb3+ concentration emanating from an Er-Yb energy transfer. The reflectance percentage of 12% was achieved in the [250-1000 nm] range, and the refractive index of 1.97 was obtained for 632 nm wavelength. These results suggest that the (3 mol. % Er, 9 mol. % Yb) codoped film is a highly efficient antireflective downconversion layer for enhancing Si solar cell efficiency.

  13. Device simulation of lead-free CH3NH3SnI3 perovskite solar cells with high efficiency

    NASA Astrophysics Data System (ADS)

    Du, Hui-Jing; Wang, Wei-Chao; Zhu, Jian-Zhuo

    2016-10-01

    The lead-free perovskite solar cells (PSCs) have drawn a great deal of research interest due to the Pb toxicity of the lead halide perovskite. CH3NH3SnI3 is a viable alternative to CH3NH3PbX3, because it has a narrower band gap of 1.3 eV and a wider visible absorption spectrum than the lead halide perovskite. The progress of fabricating tin iodide PSCs with good stability has stimulated the studies of these CH3NH3SnI3 based cells greatly. In the paper, we study the influences of various parameters on the solar cell performance through theoretical analysis and device simulation. It is found in the simulation that the solar cell performance can be improved to some extent by adjusting the doping concentration of the perovskite absorption layer and the electron affinity of the buffer and HTM, while the reduction of the defect density of the perovskite absorption layer significantly improves the cell performance. By further optimizing the parameters of the doping concentration (1.3× 1016 cm-3) and the defect density (1× 1015 cm-3) of perovskite absorption layer, and the electron affinity of buffer (4.0 eV) and HTM (2.6 eV), we finally obtain some encouraging results of the J sc of 31.59 mA/cm2, V oc of 0.92 V, FF of 79.99%, and PCE of 23.36%. The results show that the lead-free CH3NH3SnI3 PSC is a potential environmentally friendly solar cell with high efficiency. Improving the Sn2 + stability and reducing the defect density of CH3NH3SnI3 are key issues for the future research, which can be solved by improving the fabrication and encapsulation process of the cell. Project supported by the Graduate Student Education Teaching Reform Project, China (Grant No. JG201512) and the Young Teachers Research Project of Yanshan University, China (Grant No. 13LGB028).

  14. Hysteresis dependence on CH3NH3PbI3 deposition method in perovskite solar cells

    NASA Astrophysics Data System (ADS)

    Fernandes, Silvia Leticia; Bregadiolli, Bruna Andressa; Véron, Anna Christina; Nüesch, Frank A.; Zaghete, Maria Aparecida; Graeff, Carlos Frederico de Oliveira

    2016-09-01

    CH3NH3PbI3 perovskite solar cells are one of the most exciting technologies in the renewable energy field, resulting in over 20% power conversion efficiency. Deep understanding of the working principle is now required to turn the high efficiency solar cells into a reliable technology. In this work we have explored the role of deposition method on the crystallinity of perovskite films and its influence on the hysteresis behavior of the current-voltage characteristics. In addition Nb2O5 was used as hole blocking layer and its influence is also discussed. We have found that hysteresis is strongly dependent on both; perovskite deposition method and Nb2O5 thickness. The ideal condition where the hysteresis is suppressed or minimized was achieved by using the sequential deposition method for the perovskite semiconductor and a hole blocking layer of 50 nm.

  15. Solar Glaze Hazard Analysis Tool v. 3.0

    SciTech Connect

    Ho, Clifford K.; Sims, Cianan A.

    2015-08-25

    SGHAT predicts the occurrence and intensity of glare caused by a user-specified solar panel array when viewed from one or more observation points. An interactive mapping interface is used to determine the latitude, longitude and elevation of the array and observation points. The presence and intensity of glare is then calculated along a given time interval throughout the year, based on the position of the sun. The potential ocular hazard is also reported. The maximum energy production of the solar array is also estimated so that alternative designs can be compared to determine the design that yields the most energy production while mitigating glare.

  16. Estimated solar wind-implanted helium-3 distribution on the Moon

    USGS Publications Warehouse

    Johnson, J. R.; Swindle, T.D.; Lucey, P.G.

    1999-01-01

    Among the solar wind-implanted volatiles present in the lunar regolith, 3 He is possibly the most valuable resource because of its potential as a fusion fuel. The abundance of 3 He in the lunar regolith at a given location depends on surface maturity, the amount of solar wind fluence, and titanium content, because ilmenite (FeTiO3) retains helium much better than other major lunar minerals. Surface maturity and TiO2 maps from Clementine multispectral data sets are combined here with a solar wind fluence model to produce a 3He abundance map of the Moon. Comparison of the predicted 3He values to landing site observations shows good correlation. The highest 3He abundances occur in the farside maria (due to greater solar wind fluence received) and in higher TiO2 nearside mare regions.

  17. Conceptual design of a lunar base solar power plant. Lunar base systems study task 3. 3

    SciTech Connect

    Not Available

    1988-08-01

    The best available concepts for a 100 kW Solar Lunar Power Plant based on static and dynamic conversion concepts have been examined. The two concepts which emerged for direct comparison yielded a difference in delivered mass of 35 MT, the mass equivalent of 1.4 lander payloads, in favor of the static concept. The technologies considered for the various elements are either state-of-the-art or near-term. Two photovoltaic cell concepts should receive high priority for development: i.e., amorphous silicon and indium phosphide cells. The amorphous silicon, because it can be made so light weight and rugged; and the indium phosphide, because it shows very high efficiency potential and is reportedly not degraded by radiation. Also the amorphous silicon cells may be mounted on flexible backing that may roll up much like a carpet for compact storage, delivery, and ease of deployment at the base. The fuel cell and electrolysis cell technology is quite well along for lunar base applications, and because both the Shuttle and the forthcoming Space Station incorporate these devices, the status quo will be maintained. Early development of emerging improvements should be implemented so that essential life verification test programs may commence.

  18. Mass

    SciTech Connect

    Quigg, Chris

    2007-12-05

    In the classical physics we inherited from Isaac Newton, mass does not arise, it simply is. The mass of a classical object is the sum of the masses of its parts. Albert Einstein showed that the mass of a body is a measure of its energy content, inviting us to consider the origins of mass. The protons we accelerate at Fermilab are prime examples of Einsteinian matter: nearly all of their mass arises from stored energy. Missing mass led to the discovery of the noble gases, and a new form of missing mass leads us to the notion of dark matter. Starting with a brief guided tour of the meanings of mass, the colloquium will explore the multiple origins of mass. We will see how far we have come toward understanding mass, and survey the issues that guide our research today.

  19. Modulated CH3NH3PbI3-xBrx film for efficient perovskite solar cells exceeding 18.

    PubMed

    Tu, Yongguang; Wu, Jihuai; Lan, Zhang; He, Xin; Dong, Jia; Jia, Jinbiao; Guo, Panfeng; Lin, Jianming; Huang, Miaoliang; Huang, Yunfang

    2017-03-17

    The organic-inorganic lead halide perovskite layer is a crucial factor for the high performance perovskite solar cell (PSC). We introduce CH3NH3Br in the precursor solution to prepare CH3NH3PbI3-xBrx hybrid perovskite, and an uniform perovskite layer with improved crystallinity and apparent grain contour is obtained, resulting in the significant improvement of photovoltaic performance of PSCs. The effects of CH3NH3Br on the perovskite morphology, crystallinity, absorption property, charge carrier dynamics and device characteristics are discussed, and the improvement of open circuit voltage of the device depended on Br doping is confirmed. Based on above, the device based on CH3NH3PbI2.86Br0.14 exhibits a champion power conversion efficiency (PCE) of 18.02%. This study represents an efficient method for high-performance perovskite solar cell by modulating CH3NH3PbI3-xBrx film.

  20. Light stability tests of CH3NH3PbI3 perovskite solar cells using porous carbon counter electrodes.

    PubMed

    Ito, Seigo; Mizuta, Gai; Kanaya, Shusaku; Kanda, Hiroyuki; Nishina, Tomoya; Nakashima, Seiji; Fujisawa, Hironori; Shimizu, Masaru; Haruyama, Yuichi; Nishino, Hitoshi

    2016-10-21

    The CH3NH3PbI3 perovskite solar cells have been fabricated using three-porous-layered electrodes as, 〈glass/F-doped tin oxide (FTO)/dense TiO2/porous TiO2-perovskite/porous ZrO2-perovskite/porous carbon-perovskite〉 for light stability tests. Without encapsulation in air, the CH3NH3PbI3 perovskite solar cells maintained 80% of photoenergy conversion efficiency from the initial value up to 100 h under light irradiation (AM 1.5, 100 mW cm(-2)). Considering the color variation of the CH3NH3PbI3 perovskite layer, the significant improvement of light stability is due to the moisture-blocking effect of the porous carbon back electrodes. The strong interaction between carbon and CH3NH3PbI3 perovskite was proposed by the measurements of X-ray photoelectron spectroscopy and X-ray diffraction of the porous carbon-perovskite layers.

  1. Upper limits to the masses of objects in the solar comet cloud

    SciTech Connect

    Hills, J.G.

    1985-01-01

    The lack of a large steady stream of long-period comets with semi-major axes less than 2 x 10/sup 4/ AU rules out the sun having a companion more massive than about 0.01 M/sub solar/ with a semi-major axis less than about 1 x 10/sup 4/ AU. Any companion with a semi-major axis between 1 x 10/sup 4/ AU and 5 x 10/sup 4/ AU has more than a 50% probability of having entered the planetary system during the lifetime of the Solar System. The lack of apparent damage to the planetary system rules out any companion more massive than about 0.02 M/sub solar/ with a semi-major axis less than about 5 x 10/sup 4/ AU.

  2. The mean ionic charge of silicon in 3HE-rich solar flares

    NASA Technical Reports Server (NTRS)

    Luhn, A.; Klecker, B.; Hovestadt, E.; Moebius, E.

    1985-01-01

    Mean ionic charge of iron in 3He-rich solar flares and the average mean charge of Silicon for 23 #He-rich periods during the time interval from September 1978 to October 1979 were determined. It is indicated that the value of the mean charge state of Silicon is higher than the normal flare average by approximately 3 units and in perticular it is higher then the value predicted by resonant heating models for 3He-rich solar flares.

  3. ISM abundances and history: a 3D, solar neighborhood view

    NASA Astrophysics Data System (ADS)

    Lallement, R.; Vergely, J.-L.; Puspitarini, L.

    For observational reasons, the solar neighborhood is particularly suitable for the study of the multi-phase interstellar (IS) medium and the search for traces of its temporal evolution. On the other hand, by a number of aspects it seems to be a peculiar region. We use recent 3D maps of the IS dust based on color excess data as well as former maps of the gas to illustrate how such maps can be used to shed additional light on the specificity of the local medium, its history and abundance pattern. 3D maps reveal a gigantic cavity located in the third quadrant and connected to the Local Bubble, the latter itself running into an elongated cavity toward l≃ 70°. Most nearby cloud complexes of the so-called Gould belt but also more distant clouds seem to border a large fraction of this entire structure. The IS medium with the large cavity appears ionized and dust-poor, as deduced from ionized calcium and neutral sodium to dust ratios. The geometry favors the proposed scenario of Gould belt-Local Arm formation through the braking of a supercloud by interaction with a spiral density wave \\citep{olano01}. The highly variable D/H ratio in the nearby IS gas may also be spatially related to the global structure. We speculate about potential consequences of the supercloud encounter and dust-gas decoupling during its braking, in particular the formation of strong inhomogeneities in both the dust to gas abundance ratio and the dust characteristics: (i) during the ≃ 500 Myrs prior to the collision, dust within the supercloud may have been gradually, strongly enriched in D due to an absence of strong stellar formation and preferential adsorption of D \\citep{jura82,draine03} ; (ii) during its interaction with the Plane and the braking dust-rich and dust-poor regions may have formed due to differential gas drag, the dust being more concentrated in the dense areas; strong radiation pressure from OB associations at the boundary of the left-behind giant cavity may have also helped

  4. The Solar Photospheric Oxygen Abundance and the Role of 3D Model Atmospheres

    NASA Astrophysics Data System (ADS)

    Caffau, E.; Steffen, M.; Ludwig, H.-G.

    2008-09-01

    The solar oxygen abundance has undergone a major downward revision in the last decade, reputedly as a result of employing 3D hydrodynamical simulations to model the inhomogeneous structure of the solar photosphere. The very low oxygen abundance advocated by Asplund et al. 2004, A(O)=8.66, together with the downward revision of the abundances of other key elements, has created serious problems for solar models to explain the helioseismic measurements. In an effort to contribute to the dispute of whether the Sun has "solar" or "sub-solar" abundances, we have re-derived its photospheric abundance of oxygen, nitrogen, and other elements, independently of previous analyses. We applied a state-of-the art 3D (CO5BOLD) hydrodynamical simulation of the solar granulation as well as different 1D model atmospheres for the line by line spectroscopic abundance determinations. The analysis is based on both standard disk-center and full-disk spectral atlases; for oxygen we acquired in addition spectra at different heliocentric angles. The derived abundances are the result of equivalent width and/or line profile fitting of the available atomic lines. Our recommended oxygen abundance is A(O)=8.76+- 0.07, 0.1 dex higher than the value of Asplund et al. (2004). Our current estimate of the overall solar metallicity is 0.014< Z<0.016. Questions we discuss include: (i) Is the general downward revision of the solar abundances a 3D effect? (ii) How large are the abundance corrections due to horizontal inhomogeneities? (iii) What is the main reason for the differences between the abundances obtained in our study and those derived by Apslund and coworkers? (iv) How large are the uncertainties in the observed solar spectra? (v) What is the reason why the two forbidden oxygen lines, [OI] lambda 630 nm and [OI] lambda 636.3 nm, give significantly different answers for the solar oxygen abundance?

  5. Solar-wind/magnetospheric dynamos: MHD-scale collective entry of the solar wind energy, momentum and mass into the magnetosphere

    NASA Technical Reports Server (NTRS)

    Song, Yan; Lysak, Robert L.

    1992-01-01

    A quasi open MHD (Magnetohydrodynamic) scale anomalous transport controlled boundary layer model is proposed, where the MHD collective behavior of magnetofluids (direct dynamo effect, anomalous viscous interaction and anomalous diffusion of the mass and the magnetic field) plays the main role in the conversion of the Solar Wind (SW) kinetic and magnetic energy into electromagnetic energy in the Magnetosphere (MSp). The so called direct and indirect dynamo effects are based on inductive and purely dissipative energy conversion, respectively. The self organization ability of vector fields in turbulent magnetofluids implies an inductive response of the plasma, which leads to the direct dynamo effect. The direct dynamo effect describes the direct formation of localized field aligned currents and the transverse Alfven waves and provides a source for MHD scale anomalous diffusivity and viscosity. The SW/MSp coupling depends on the dynamo efficiency.

  6. Non-renormalizable operators for solar neutrino mass generation in Split SuSy with bilinear R-parity violation

    NASA Astrophysics Data System (ADS)

    Díaz, Marco Aurelio; Koch, Benjamin; Rojas, Nicolás

    2017-03-01

    The Minimal Supersymmetric Extension of the Standard Model (MSSM) is able to explain the current data from neutrino physics. Unfortunately Split Supersymmetry as low energy approximation of this theory fails to generate a solar square mass difference, including after the addition of bilinear R-Parity Violation. In this work, it is shown how one can derive an effective low energy theory from the MSSM in the spirit of Split Supersymmetry, which has the potential of explaining the neutrino phenomenology. This is achieved by going beyond leading order in the process of integrating out heavy scalars from the original theory, which results in non-renormalizable operators in the effective low energy theory. It is found that in particular a d = 8 operator is crucial for the generation of the neutrino mass differences.

  7. He I D3 OBSERVATIONS OF THE 1984 MAY 22 M6.3 SOLAR FLARE

    SciTech Connect

    Liu Chang; Xu Yan; Deng Na; Lee, Jeongwoo; Zhang Jifeng; Wang Haimin; Prasad Choudhary, Debi

    2013-09-01

    The He I D3 line has a unique response to a flare impact on the low solar atmosphere and can be a powerful diagnostic tool for energy transport processes. Using images obtained from the recently digitized films of the Big Bear Solar Observatory, we report D3 observations of the M6.3 flare on 1984 May 22, which occurred in an active region with a circular magnetic polarity inversion line (PIL). The impulsive phase of the flare starts with a main elongated source that darkens in D3, inside of which bright emission kernels appear at the time of the initial small peak in hard X-rays (HXRs). These flare cores subsequently evolve into a sharp emission strand lying within the dark halo; this evolution occurs at the same time as the main peak in HXRs, reversing the overall source contrast from -5% to 5%. The radiated energy in D3 during the main peak is estimated to be about 10{sup 30} erg, which is comparable to that carried by nonthermal electrons above 20 keV. Afterward, the flare proceeds along the circular PIL in the counterclockwise direction to form a dark circular ribbon in D3, which apparently mirrors the bright ribbons in H{alpha} and He I 10830 A. All of these ribbons last for over one hour in the late gradual phase. We suggest that the present event resembles the so-called black-light flare that was proposed based on continuum images, and that D3 darkening and brightening features herein may be due to thermal conduction heating and the direct precipitation of high-energy electrons, respectively.

  8. Induced mass and wave motions in the lower solar atmosphere. I - Effects of shear motion of flux tubes

    NASA Technical Reports Server (NTRS)

    Wu, S. T.; Hu, Y. Q.; Nakagawa, Y.; Tandberg-Hanssen, E.

    1983-01-01

    Observations indicate that various dynamic solar phenomena lead to enhanced emission of electromagnetic waves from radio to X-ray wavelengths which can be traced to magnetic activity in the photospheric level. A number of previous investigations have ignored the dynamic responses in the solar atmosphere. On the other hand, Nakagawa et al. (1978, 1981) have studied the atmospheric responses in the frame of MHD in the supersonic super-Alfvenic region. Studies of the slowly varying dynamic response (subsonic) have been unsuccessful because of the requirements of high accuracy in the numerical scheme in which a rigorous mathematical treatment of the boundary conditions is necessary. Recently, a numerical MHD model was constructed by using the full implicit continuous eulerian method. The present investigation makes use of a method which is written in a more convenient numerical code. A two-dimensional, time-dependent, nonplanar MHD model is used to investigate the induced mass and wave motions in the lower solar atmosphere due to the shear motion of flux tubes.

  9. 3X compound parabolic concentrating (CPC) solar energy collector. Final technical report

    SciTech Connect

    Ballheim, R.W.

    1980-04-25

    Chamberlain engineers designed a 3X compound parabolic concentrating (CPC) collector for the subject contract. The collector is a completely housed, 105.75 x 44.75 x 10.23-inch, 240-pound unit with six each evacuated receiver assemblies, a center manifold and a one-piece glass cover. A truncated version of a CPC trough reflector system and the General Electric Company tubular evacuated receiver have been integrated with a mass producible collector design suitable for operation at 250 to 450/sup 0/F. The key criterion for optimization of the design was minimization of the cost per Btu collected annually at an operating temperature of 400/sup 0/F. The reflector is a 4.1X design truncated to a total height of 8.0 inches with a resulting actual concentration ratio of 2.6 to 1. The manifold is an insulated area housing the fluid lines which connect the six receivers in series with inlet and outlet tubes extending from one side of the collector at the center. The reflectors are polished, anodized aluminum which are shaped by the roll form process. The housing is painted, galvanized steel, and the cover glass is 3/16-inch thick tempered, low iron glass. The collector requires four slope adjustments per year for optimum effectiveness. Chamberlain produced ten 3X CPC collectors for the subject contract. Two collectors were used to evaluate assembly procedures, six were sent to the project officer in Albuquerque, New Mexico, one was sent to Argonne National Laboratory for performance testing and one remained with the Company. A manufacturing cost study was conducted to estimate limited mass production costs, explore cost reduction ideas and define tooling requirements. The final effort discussed shows the preliminary design for application of a 3X CPC solar collector system for use in the Iowa State Capitol complex.

  10. The deuterium fractionation of water on solar-system scales in deeply-embedded low-mass protostars

    NASA Astrophysics Data System (ADS)

    Persson, M. V.; Jørgensen, J. K.; van Dishoeck, E. F.; Harsono, D.

    2014-03-01

    Context. The chemical evolution of water through the star formation process directly affects the initial conditions of planet formation. The water deuterium fractionation (HDO/H2O abundance ratio) has traditionally been used to infer the amount of water brought to Earth by comets. Measuring this ratio in deeply-embedded low-mass protostars makes it possible to probe the critical stage when water is transported from clouds to disks in which icy bodies are formed. Aims: We aim to determine the HDO/H2O abundance ratio in the warm gas in the inner 150 AU for three deeply-embedded low-mass protostars NGC 1333-IRAS 2A, IRAS 4A-NW, and IRAS 4B through high-resolution interferometric observations of isotopologues of water. Methods: We present sub-arcsecond resolution observations of the 31,2-22,1 transition of HDO at 225.89672 GHz in combination with previous observations of the 31,3-22,0 transition of H218O at 203.40752 GHz from the Plateau de Bure Interferometer toward three low-mass protostars. The observations have similar angular resolution (0.̋7-1.̋3), probing scales R ≲ 150 AU. In addition, observations of the 21,1-21,2 transition of HDO at 241.561 GHz toward IRAS 2A are presented to constrain the excitation temperature. A direct and model independent HDO/H2O abundance ratio is determined for each source and compared with HDO/H2O ratios derived from spherically symmetric full radiative transfer models for two sources. Results: From the two HDO lines observed toward IRAS 2A, the excitation temperature is found to be Tex = 124 ± 60 K. Assuming a similar excitation temperature for H218O and all sources, the HDO/H2O ratio is 7.4 ± 2.1 × 10-4 for IRAS 2A, 19.1 ± 5.4 × 10-4 for IRAS 4A-NW, and 5.9 ± 1.7 × 10-4 for IRAS 4B. The abundance ratios show only a weak dependence on the adopted excitation temperature. The abundances derived from the radiative transfer models agree with the direct determination of the HDO/H2O abundance ratio for IRAS 16293-2422 within a

  11. The efficiency limit of CH{sub 3}NH{sub 3}PbI{sub 3} perovskite solar cells

    SciTech Connect

    Sha, Wei E. I.; Ren, Xingang; Chen, Luzhou; Choy, Wallace C. H.

    2015-06-01

    With the consideration of photon recycling effect, the efficiency limit of methylammonium lead iodide (CH{sub 3}NH{sub 3}PbI{sub 3}) perovskite solar cells is predicted by a detailed balance model. To obtain convincing predictions, both AM 1.5 spectrum of Sun and experimentally measured complex refractive index of perovskite material are employed in the detailed balance model. The roles of light trapping and angular restriction in improving the maximal output power of thin-film perovskite solar cells are also clarified. The efficiency limit of perovskite cells (without the angular restriction) is about 31%, which approaches to Shockley-Queisser limit (33%) achievable by gallium arsenide (GaAs) cells. Moreover, the Shockley-Queisser limit could be reached with a 200 nm-thick perovskite solar cell, through integrating a wavelength-dependent angular-restriction design with a textured light-trapping structure. Additionally, the influence of the trap-assisted nonradiative recombination on the device efficiency is investigated. The work is fundamentally important to high-performance perovskite photovoltaics.

  12. Lithium Inventory of 2 Solar Mass Red Clump Stars in Open Clusters: A Test of the Helium Flash Mechanism

    NASA Technical Reports Server (NTRS)

    Carlberg, Joleen K.; Cunha, Katia; Smith, Verne V.

    2016-01-01

    The temperature distribution of field Li-rich red giants suggests the presence of a population of Li-rich red clump (RC) stars. One proposed explanation for this population is that all stars with masses near 2 solar mass experience a shortlived phase of Li-richness at the onset of core He-burning. Many of these stars have low C-12/C-13, a signature of deep mixing that is presumably associated with the Li regeneration. To test this purported mechanism of Li enrichment, we measured abundances in 38 RC stars and 6 red giant branch (RGB) stars in four open clusters selected to have RC masses near 2 solar mass. We find six Li-rich stars (A(Li) greater than or equal to 1.50 dex) of which only two may be RC stars. None of the RC stars have Li exceeding the levels observed in the RGB stars, but given the brevity of the suggested Li-rich phase and the modest sample size, it is probable that stars with larger Li-enrichments were missed simply by chance. However, we find very few stars in our sample with low C-12/C-13. Such low C-12/C-13, seen in many field Li-rich stars, should persist even after lithium has returned to normal low levels. Thus, if Li synthesis during the He flash occurs, it is a rare, but potentially long-lived occurrence rather than a short-lived phase for all stars. We estimate a conservative upper limit of the fraction of stars going through a Li-rich phase to be less than 47%, based on stars that have low C-12/C-13 for their observed A(Li).

  13. Unexpected Performances of Flat Sb2S3-Based Hybrid Extremely Thin Absorber Solar Cells

    NASA Astrophysics Data System (ADS)

    Muto, Takuma; Larramona, Gerardo; Dennler, Gilles

    2013-07-01

    We report unexpected results obtained on hybrid extremely thin absorber (ETA) solar cells based on the structure TiO2/Sb2S3/poly(3-hexylthiophene)/hole conducting layer (HCL). We show that we can maintain a large, state-of-the-art short-circuit current by switching from a three-dimensional to a two-dimensional device, that is, by simplifying drastically the device structure. Moreover, we prove that the HCL plays an important role in the solar cell working mechanism, and influences significantly its open-circuit voltage. We believe that these findings suggest new directions for the optimization of solid-state sensitized solar cells.

  14. Detection of stratospheric HNO3 and NO2 response to short-term solar ultraviolet variability

    NASA Astrophysics Data System (ADS)

    Keating, G. M.; Nicholson, J., III; Brasseur, G.; de Rudder, A.; Schmailzl, U.

    1986-07-01

    It is pointed out that variations in the solar ultraviolet irradiance with a period equal to or approximately one-half of the rotation period of the sun are currently observed by satellite monitoring. Information regarding the response of stratospheric species to solar ultraviolet variability is indispensable for an understanding of the photochemical behavior of the middle atmosphere. Relations are considered between LIMS (limb infrared monitor of the stratosphere) measurements of HNO3 and NO2, and the SBUV (solar backscatter ultraviolet) measurements of short-term variations in 205-nm radiation. It is found that the response of HNO3 is much stronger than, but in the opposite sense to the ozone response, while the NO2 response is in the opposite sense to the HNO3 response. Model calculations predict large variations in HNO3 over the 11-yr solar cycle.

  15. Solar-wind velocity measurements from near-Sun comets C/2011 W3 (Lovejoy), C/2011 L4 (Pan-STARRS), and C/2012 S1 (ISON)

    NASA Astrophysics Data System (ADS)

    Ramanjooloo, Y.; Jones, G. H.; Coates, A.; Owens, M. J.; Battams, K.

    2014-07-01

    Since the mid-20th century, comets' plasma (type I) tails have been studied as natural probes of the solar wind [1]. Comets have induced magnetotails, formed through the draping of the heliospheric magnetic field by the velocity shear in the mass-loaded solar wind. These can be easily observed remotely as the comets' plasma tails, which generally point away from the Sun. Local solar-wind conditions directly influence the morphology and dynamics of a comet's plasma tail. During ideal observing geometries, the orientation and structure of the plasma tail can reveal large-scale and small-scale variations in the local solar-wind structure. These variations can be manifested as tail condensations, kinks, and disconnection events. Over 50 % of observed catalogued comets are sungrazing comets [2], fragments of three different parent comets. Since 2011, two bright new comets, C/2011 W3 [3] (from hereon comet Lovejoy) and C/2012 S1 [4] (hereon comet ISON) have experienced extreme solar-wind conditions and insolation of their nucleus during their perihelion passages, approaching to within 8.3×10^5 km (1.19 solar radii) and 1.9×10^6 km (2.79 solar radii) of the solar centre. They each displayed a prominent plasma tail, proving to be exceptions amongst the observed group of sungrazing comets. These bright sungrazers provide unprecedented access to study the solar wind in the heretofore unprobed innermost region of the solar corona. The closest spacecraft in-situ sampling of the solar wind by the Helios probes reached 0.29 au. For this study, we define a sungrazing comet as one with its perihelion within the solar Roche limit (3.70 solar radii). We also extend this study to include C/2011 L4 [5] (comet Pan-STARRS), a comet with a much further perihelion distance of 0.302 au. The technique employed in this study was first established by analysing geocentric amateur observations of comets C/2001 Q4 (NEAT) and C/2004 Q2 (Machholz) [7]. These amateur images, obtained with modern

  16. 3D Solar Wind Structure Features Characterizing the Rise of Cycle 24

    NASA Astrophysics Data System (ADS)

    Luhmann, J. G.; Ellenburg, M. A.; Riley, P.; Lee, C. O.; Arge, C. N.; Jian, L.; Russell, C. T.; Simunac, K.; Galvin, A. B.; Petrie, G. J.

    2011-12-01

    Since the launch of the STEREO mission in 2006, there has been renewed interest in the 3D structure of the solar wind, spurred in part by the unusual cycle 23 solar minimum and current solar cycle rise. Of particular significance for this subject has been the ubiquitous occurrence of low latitude coronal holes and coronal pseudo-streamers. These coupled features have been common both because of the relative strength of high order spherical harmonic content of the global coronal field, and the weakness of the field compared to the previous two well-observed cycles. We consider the effects of the low latitude coronal holes and pseudo-streamers on the near-ecliptic solar wind and interplanetary field. In particular, we illustrate how the now common passage of streams with low latitude sources and pseudo-streamer boundaries is changing our traditional perceptions of local solar wind structures.

  17. Preparation of 1-methyl-3-propylimidazolium acetate and its application in dye sensitized solar cells

    SciTech Connect

    Zhang, Zhihai; Wu, Yucheng; Ge, Qian; Sun, Songquan; Shi, Chengwu

    2010-03-15

    In this paper, we reported the preparation of 1-methyl-3-propylimidazolium acetate (MPIAc), which proceeded via the metathesis of 1-methyl-3-propylimidazolium iodide (MPII) and lead acetate or potassium acetate. The apparent diffusion coefficients of triiodide and iodide in binary ionic liquids, MPIAc and MPII with various weight ratios, were demonstrated by cyclic voltammetry using a Pt ultramicroelectrode. It was found that the apparent diffusion coefficients of triiodide increased and those of iodide slightly increased with the weight ratio increase of MPIAc and MPII. The dye sensitized solar cells with the electrolyte, which was composed of 0.13 M I{sub 2}, 0.10 M LiI, 0.50 M 4-tert-butylpyrdine in the binary ionic liquid electrolyte of MPIAc (employing potassium acetate) and MPII (weight ratio 0.2), gave short circuit photocurrent density of 9.40 mA cm{sup -2}, open circuit voltage of 0.62 V, and fill factor of 0.57, corresponding to the photoelectric conversion efficiency of 3.34% at the illumination (air mass 1.5, 100 mW cm{sup -2}). (author)

  18. FIRST PRECISION LIGHT CURVE ANALYSIS OF THE NEGLECTED EXTREME MASS RATIO SOLAR-TYPE BINARY HR BOOTIS

    SciTech Connect

    Samec, Ronald G.; Benkendorf, Barry; Dignan, James B.; Robb, Russell; Kring, James; Faulkner, Danny R.

    2015-04-15

    HR Bootis is a neglected binary that is found to be a solar-type (G2V) extreme mass ratio binary (EMRB). It was discovered by Hanley and Shapley in 1940. Surprisingly, little has been published in the intervening years. In 1999 it was characterized by a 0.31587 day orbital period. Since that time it has been observed by various observers who have determined ∼20 timings of minimum light over the past ∼15,000 orbits. Our observations in 2012 represent the first precision curves in the BVR{sub c}I{sub c} Johnson–Cousins wavelength bands. The light curves have rather low amplitudes, averaging some 0.5 magnitudes, yet they exhibit total eclipses, which is typical of the rare group of solar-type EMRBs. An improved linear ephemeris was computed along with a quadratic ephemeris showing a decaying orbit, which indicates magnetic breaking may be occurring. The light curve solution reveals that HR Boo is a contact system with a somewhat low 21% Roche-lobe fill-out but a mass ratio of q = 4.09 (0.2444), which defines it as an EMRB. Two spots, both hot, were allowed to iterate to fit the light curve asymmetries. Their radii are 32° and 16°. Both are high-latitude polar spots indicative of strong magnetic activity. The shallow contact yet nearly equal component temperatures makes it an unusual addition to this group.

  19. Solar neon abundances from gamma-ray spectroscopy and He-3-rich particle events

    NASA Technical Reports Server (NTRS)

    Reames, D. V.; Ramaty, R.; Von Rosenvinge, T. T.

    1988-01-01

    Ambient solar atmospheric abundances derived from gamma-ray spectroscopy are compared with observations of solar energetic particles. Agreement is found between the gamma-ray-derived Ne/O ratio and the corresponding mean ratio for He-3-rich flares. Both of these values are significantly higher than inferred coronal Ne/O ratios. It is suggested that the mean Ne/O ratio in He-3-rich flares reflects the composition of the flare plasma rather than the acceleration process.

  20. Stellar mass to halo mass relation from galaxy clustering in VUDS: a high star formation efficiency at z ≃ 3

    NASA Astrophysics Data System (ADS)

    Durkalec, A.; Le Fèvre, O.; de la Torre, S.; Pollo, A.; Cassata, P.; Garilli, B.; Le Brun, V.; Lemaux, B. C.; Maccagni, D.; Pentericci, L.; Tasca, L. A. M.; Thomas, R.; Vanzella, E.; Zamorani, G.; Zucca, E.; Amorín, R.; Bardelli, S.; Cassarà, L. P.; Castellano, M.; Cimatti, A.; Cucciati, O.; Fontana, A.; Giavalisco, M.; Grazian, A.; Hathi, N. P.; Ilbert, O.; Paltani, S.; Ribeiro, B.; Schaerer, D.; Scodeggio, M.; Sommariva, V.; Talia, M.; Tresse, L.; Vergani, D.; Capak, P.; Charlot, S.; Contini, T.; Cuby, J. G.; Dunlop, J.; Fotopoulou, S.; Koekemoer, A.; López-Sanjuan, C.; Mellier, Y.; Pforr, J.; Salvato, M.; Scoville, N.; Taniguchi, Y.; Wang, P. W.

    2015-04-01

    The relation between the galaxy stellar mass M⋆ and the dark matter halo mass Mh gives important information on the efficiency in forming stars and assembling stellar mass in galaxies. We present measurements of the ratio of stellar mass to halo mass (SMHR) at redshifts 2 < z < 5, obtained from the VIMOS Ultra Deep Survey. We use halo occupation distribution (HOD) modelling of clustering measurements on ~3000 galaxies with spectroscopic redshifts to derive the dark matter halo mass Mh, and spectral energy density fitting over a large set of multi-wavelength data to derive the stellar mass M⋆ and compute the SMHR = M⋆/Mh. We find that the SMHR ranges from 1% to 2.5% for galaxies with M⋆ = 1.3 × 109 M⊙ to M⋆ = 7.4 × 109 M⊙ in DM halos with Mh = 1.3 × 1011 M⊙ to Mh = 3 × 1011 M⊙. We derive the integrated star formation efficiency (ISFE) of these galaxies and find that the star formation efficiency is a moderate 6-9% for lower mass galaxies, while it is relatively high at 16% for galaxies with the median stellar mass of the sample ~ 7 × 109 M⊙. The lower ISFE at lower masses may indicate that some efficient means of suppressing star formation is at work (like SNe feedback), while the high ISFE for the average galaxy at z ~ 3 indicates that these galaxies efficiently build up their stellar mass at a key epoch in the mass assembly process. Based on our results, we propose a possible scenario in which the average massive galaxy at z ~ 3 begins to experience truncation of its star formation within a few million years. Based on data obtained with the European Southern Observatory Very Large Telescope, Paranal, Chile, under Large Program 185.A-0791.

  1. SPITZER OBSERVATIONS OF THE {lambda} ORIONIS CLUSTER. II. DISKS AROUND SOLAR-TYPE AND LOW-MASS STARS

    SciTech Connect

    Hernandez, Jesus; Morales-Calderon, Maria; Calvet, Nuria; Hartmann, L.; Muzerolle, J.; Gutermuth, R.; Luhman, K. L.; Stauffer, J. E-mail: muzerol@stsci.ed

    2010-10-20

    We present IRAC/MIPS Spitzer Space Telescope observations of the solar-type and the low-mass stellar population of the young ({approx}5 Myr) {lambda} Orionis cluster. Combining optical and Two Micron All Sky Survey photometry, we identify 436 stars as probable members of the cluster. Given the distance (450 pc) and the age of the cluster, our sample ranges in mass from 2 M{sub sun} to objects below the substellar limit. With the addition of the Spitzer mid-infrared data, we have identified 49 stars bearing disks in the stellar cluster. Using spectral energy distribution slopes, we place objects in several classes: non-excess stars (diskless), stars with optically thick disks, stars with 'evolved disks' (with smaller excesses than optically thick disk systems), and 'transitional disk' candidates (in which the inner disk is partially or fully cleared). The disk fraction depends on the stellar mass, ranging from {approx}6% for K-type stars (R{sub C} - J < 2) to {approx}27% for stars with spectral-type M5 or later (R{sub C} - J>4). We confirm the dependence of disk fraction on stellar mass in this age range found in other studies. Regarding clustering levels, the overall fraction of disks in the {lambda} Orionis cluster is similar to those reported in other stellar groups with ages normally quoted as {approx}5 Myr.

  2. Western Wind and Solar Integration Study Phase 3 – Frequency Response and Transient Stability

    SciTech Connect

    Miller, N. W.; Shao, M.; Pajic, S.; D'Aquila, R.

    2014-12-01

    Power system operators and utilities worldwide have concerns about the impact of high-penetration wind and solar generation on electric grid reliability (EirGrid 2011b, Hydro-Quebec 2006, ERCOT 2010). The stability of North American grids under these conditions is a particular concern and possible impediment to reaching future renewable energy goals. Phase 3 of the Western Wind and Solar Integration Study (WWSIS-3) considers a 33% wind and solar annual energy penetration level that results in substantial changes to the characteristics of the bulk power system, including different power flow patterns, different commitment and dispatch of existing synchronous generation, and different dynamic behavior of wind and solar generation. WWSIS-3 evaluates two specific aspects of fundamental frequency system stability: frequency response and transient stability.

  3. Stacbeam - An efficient, low-mass, sequentially deployable structure. [for satellite solar power

    NASA Technical Reports Server (NTRS)

    Adams, L. R.

    1982-01-01

    Design features of the stacking triangular articulated compact beam (Stacbeam) as a candidate truss structure for GEOS spacecraft solar power arrays are explored. Solar arrays of increasing size require folding, noninterfering structures, minimal thermal effects, slow and controlled deployment, and a high aspect ratio. The Stacbeam consists of a triangular batten frame perpendicular to the beam axis, three longerons attached at the corners of the batten frame and mounted parallel to the beam axis, and three diagonals to provide shear and torsional stiffness. Locking hinges are installed at the midpoint and ends of each longeron and at the midpoint and ends of each diagonal. The material is graphite/epoxy composite with a 120 GPa modulus and a 1500 kg/sq m density. Successful vertical deployment on the ground has been effected with a prototype deployer, together with horizontal cantilever in a fully deployed configuration.

  4. Quantitative Imaging of the Solar Wind: CME Mass Evolution and the Interplanetary Magnetic Flux Balance

    NASA Astrophysics Data System (ADS)

    DeForest, Craig

    2012-05-01

    We recently developed post-processing techniques for heliospheric images from the STEREO spacecraft; the new data sets enable, for the first time, quantitative photometric studies of evolving wind features at distances up to 1 A.U. from the Sun. We have used the new data to trace several CMEs and magnetic disconnection events to their origins in the solar corona, and to infer the force balance and entrained magnetic flux in those features. We present recent results showing the relationship between ICME and CME anatomy, in particular the origin of an observed interplanetary flux rope and the relationship between original launched solar material and piled-up sheath material and flux in the storm at 1. A.U. We discuss implications for understanding space weather physics and predicting individual events, and point out the importance of future imaging technologies such as polarized heliospheric imaging.

  5. Absorption enhancement in CH3NH3PbI3 solar cell using a TiO2/MoS2 nanocomposite electron selective contact

    NASA Astrophysics Data System (ADS)

    Imran Ahmed, Muhammad; Hussain, Zakir; Khalid, Amir; Noman Amin, Hafiz Muhammad; Habib, Amir

    2016-04-01

    In the present contribution, perovskite absorbers have been combined with few layer thick MoS2 semiconductor to put together a solar cell allowing broad spectrum harvesting of solar radiations. Such modification allows to achieve solar light harvesting at the band edges, addressing a drawback of CH3NH3PbI3 absorbers. We recorded an improved efficiency from 3.7% to 4.3% on the back of this methodology. We have also worked out a novel methodology to synthesize TiO2/MoS2 nanocomposite by in situ dispersion of liquid exfoliated MoS2 sheets in the sol gel reaction.

  6. A thermodynamic and mechanical model for formation of the Solar System via 3-dimensional collapse of the dusty pre-solar nebula

    NASA Astrophysics Data System (ADS)

    Hofmeister, Anne M.; Criss, Robert E.

    2012-03-01

    The fundamental and shared rotational characteristics of the Solar System (nearly circular, co-planar orbits and mostly upright axial spins of the planets) record conditions of origin, yet are not explained by prevailing 2-dimensional disk models. Current planetary spin and orbital rotational energies (R.E.) each nearly equal and linearly depend on gravitational self-potential of formation (Ug), revealing mechanical energy conservation. We derive -ΔUg≅Δ.R.E. and stability criteria from thermodynamic principles, and parlay these relationships into a detailed model of simultaneous accretion of the protoSun and planets from the dust-bearing 3-d pre-solar nebula (PSN). Gravitational heating is insignificant because Ug is negative, the 2nd law of thermodynamics must be fulfilled, and ideal gas conditions pertain to the rarified PSN until the objects were nearly fully formed. Combined conservation of angular momentum and mechanical energy during 3-dimensional collapse of spheroidal dust shells in a contracting nebula provides ΔR.E.≅R.E. for the central body, whereas for formation of orbiting bodies, ΔR.E.≅R.E.f(1-If/Ii), where I is the moment of inertia. Orbital data for the inner planets follow 0.04×R.E.f≅-Ug which confirms conservation of angular momentum. Significant loss of spin, attributed to viscous dissipation during differential rotation, masks the initial spin of the un-ignited protoSun predicted by R.E.=-Ug. Heat production occurs after nearly final sizes are reached via mechanisms such as shear during differential rotation and radioactivity. We focus on the dilute stage, showing that the PSN was compositionally graded due to light molecules diffusing preferentially, providing the observed planetary chemistry, and set limits on PSN mass, density, and temperature. From measured planetary masses and orbital characteristics, accounting for dissipation of spin, we deduce mechanisms and the sequence of converting a 3-d dusty cloud to the present 2-d

  7. Strong covalency-induced recombination centers in perovskite solar cell material CH3NH3PbI3.

    PubMed

    Agiorgousis, Michael L; Sun, Yi-Yang; Zeng, Hao; Zhang, Shengbai

    2014-10-15

    Inorganic-organic hybrid perovskites are a new family of solar cell materials, which have recently been used to make solar cells with efficiency approaching 20%. Here, we report the unique defect chemistry of the prototype material, CH3NH3PbI3, based on first-principles calculation. We found that both the Pb cations and I anions in this material exhibit strong covalency as characterized by the formation of Pb dimers and I trimers with strong covalent bonds at some of the intrinsic defects. The Pb dimers and I trimers are only stabilized in a particular charge state with significantly lowered energy, which leads to deep charge-state transition levels within the band gap, in contradiction to a recent proposal that this system has only shallow intrinsic defects. Our results show that, in order to prevent the deep-level defects from being effective recombination centers, the equilibrium carrier concentrations should be controlled so that the Fermi energy is about 0.3 eV away from the band edges. Beyond this range, according to a Shockley-Read-Hall analysis, the non-equilibrium carrier lifetime will be strongly affected by the concentration of I vacancies and the anti-site defects with I occupying a CH3NH3 site.

  8. Solar flares associated coronal mass ejections in case of type II radio bursts

    NASA Astrophysics Data System (ADS)

    Bhatt, Beena; Prasad, Lalan; Chandra, Harish; Garia, Suman

    2016-08-01

    We have statistically studied 220 events from 1996 to 2008 (i.e. solar cycle 23). Two set of flare-CME is examined one with Deca-hectometric (DH) type II and other without DH type II radio burst. Out of 220 events 135 (flare-halo CME) are accompanied with DH type II radio burst and 85 are without DH type II radio burst. Statistical analysis is performed to examine the distribution of solar flare-halo CME around the solar disk and to investigate the relationship between solar flare and halo CME parameters in case of with and without DH type II radio burst. In our analysis we have observed that: (i) 10-20° latitudinal belt is more effective than the other belts for DH type II and without DH type II radio burst. In this belt, the southern region is more effective in case of DH type II radio burst, whereas in case of without DH type II radio burst dominance exits in the northern region. (ii) 0-10° longitudinal belt is more effective than the other belts for DH type II radio burst and without DH type II radio burst. In this belt, the western region is more effective in case of DH type II radio burst, while in case of without DH type II radio burst dominance exits in the eastern region. (iii) Mean speed of halo CMEs (1382 km/s) with DH type II radio burst is more than the mean speed of halo CMEs (775 km/s) without DH type II radio burst. (iv) Maximum number of M-class flares is found in both the cases. (v) Average speed of halo CMEs in each class accompanied with DH type II radio burst is higher than the average speed of halo CMEs in each class without DH type II radio burst. (vi) Average speed of halo CMEs, associated with X-class flares, is greater than the other class of solar flares in both the cases.

  9. Solar power satellite system definition study. Part 3: Preferred concept system definition

    NASA Technical Reports Server (NTRS)

    1978-01-01

    A concise but complete system description for the preferred concept of the Solar Power Satellite System is presented. Significant selection decisions included the following: (1) single crystal silicon solar cells; (2) glass encapsulated solar cell blankets; (3) concentration ratio 1; (4) graphite composite materials for primary structure; (5) electric propulsion for attitude control; (6) klystron RF amplifier tubes for the transmitter; (7) one kilometer diameter transmitter with a design trans mission link output power of 5,000 megawatts; (8) construction in low earth orbit with self-powered transfer of satellite modules to geosynchronous orbit; and (9) two-stage winged fully reusable rocket vehicle for transportation to low earth orbit.

  10. Theory of Type 3 and Type 2 Solar Radio Emissions

    NASA Technical Reports Server (NTRS)

    Robinson, P. A.; Cairns, I. H.

    2000-01-01

    The main features of some current theories of type III and type II bursts are outlined. Among the most common solar radio bursts, type III bursts are produced at frequencies of 10 kHz to a few GHz when electron beams are ejected from solar active regions, entering the corona and solar wind at typical speeds of 0.1c. These beams provide energy to generate Langmuir waves via a streaming instability. In the current stochastic-growth theory, Langmuir waves grow in clumps associated with random low-frequency density fluctuations, leading to the observed spiky waves. Nonlinear wave-wave interactions then lead to secondary emission of observable radio waves near the fundamental and harmonic of the plasma frequency. Subsequent scattering processes modify the dynamic radio spectra, while back-reaction of Langmuir waves on the beam causes it to fluctuate about a state of marginal stability. Theories based on these ideas can account for the observed properties of type III bursts, including the in situ waves and the dynamic spectra of the radiation. Type 11 bursts are associated with shock waves propagating through the corona and interplanetary space and radiating from roughly 30 kHz to 1 GHz. Their basic emission mechanisms are believed to be similar to those of type III events and radiation from Earth's foreshock. However, several sub-classes of type II bursts may exist with different source regions and detailed characteristics. Theoretical models for type II bursts are briefly reviewed, focusing on a model with emission from a foreshock region upstream of the shock for which observational evidence has just been reported.

  11. Spraylon fluorocarbon encapsulation for silicon solar cell arrays, phase 3

    NASA Technical Reports Server (NTRS)

    Naes, L. G.

    1978-01-01

    The liquid transparent film-forming, fluorocarbon, Spraylon, a protective coating for terrestrial solar cell modules was evaluated. Two modules were completed and field tested. Problems developed early in the field testing which led to the shortened test period, specifically, lifting of the antireflection coating, followed in some areas by complete film delamination. It is believed that although these problems were certainly induced by the presence of the SPRAYLON film, they were not failures of the material per se. Instead, assembly procedures, module design, and cell coating quality should be evaluated to determine cause of failure.

  12. SDO: Complex Mass of Plasma

    NASA Video Gallery

    A small, but complex mass of solar material gyrated and spun about over the course of 40 hours above the surface of the sun on Sept. 1-3, 2015. It was stretched and pulled back and forth by powerfu...

  13. Evolution of Intrinsic Scatter in the SFR-Stellar Mass Correlation at 0.5 less than z Less Than 3

    NASA Technical Reports Server (NTRS)

    Kurczynski, Peter; Gawiser, Eric; Acquaviva, Viviana; Bell, Eric F.; Dekel, Avishai; De Mello, Duilia F.; Ferguson, Henry C.; Gardner, Jonathan P.; Grogin, Norman A.

    2016-01-01

    We present estimates of intrinsic scatter in the star formation rate (SFR)--stellar mass (M*) correlation in the redshift range 0.5 less than z less than 3.0 and in the mass range 10(exp 7) less than M* less than 10(exp 11) solar mass. We utilize photometry in the Hubble Ultradeep Field (HUDF12) and Ultraviolet Ultra Deep Field (UVUDF) campaigns and CANDELS/GOODS-S and estimate SFR, M* from broadband spectral energy distributions and the best-available redshifts. The maximum depth of the UDF photometry (F160W 29.9 AB, 5 sigma depth) probes the SFR--M* correlation down to M* approximately 10(exp 7) solar mass, a factor of 10-100 x lower in M* than previous studies, and comparable to dwarf galaxies in the local universe. We find the slope of the SFR-M* relationship to be near unity at all redshifts and the normalization to decrease with cosmic time. We find a moderate increase in intrinsic scatter with cosmic time from 0.2 to 0.4 dex across the epoch of peak cosmic star formation. None of our redshift bins show a statistically significant increase in intrinsic scatter approximately 100 Myr. Our results are consistent with a picture of gradual and self-similar assembly of galaxies across more than three orders of magnitude in stellar mass from as low as 10(exp 7) solar mass.

  14. Optimization of solar cells for air mass zero operation and a study of solar cells at high temperatures

    NASA Technical Reports Server (NTRS)

    Hovel, H. J.; Vernon, S. M.

    1982-01-01

    The power to weight ratio of GaAs cells can be reduced by fabricating devices using thin GaAs films on low density substrate materials (silicon, glass, plastics). A graphoepitaxy technique was developed which uses fine geometric patterns in the substrate to affect growth. Initial substrates were processed by etching 25 microns deep grooves into 100 oriented wafers; fine-grained polycrystalline GaAs layers 25-50 microns thick were then deposited on these and recrystallization was performed, heating the substrates to above the GaAs melting point in ASH3 atmosphere, resulting in large grain regrowth oriented along the groove dimensions. Experiments with smaller groove depths and spacings were initially encouraging; single large GaAs grains would totally cover one and often two groove fields of 14 groove each spanning several hundred microns. Dielectric coatings on the grooved substrates were also used to modify the growth.

  15. LSD: Lyman-break galaxies Stellar populations and Dynamics - I. Mass, metallicity and gas at z ~ 3.1

    NASA Astrophysics Data System (ADS)

    Mannucci, F.; Cresci, G.; Maiolino, R.; Marconi, A.; Pastorini, G.; Pozzetti, L.; Gnerucci, A.; Risaliti, G.; Schneider, R.; Lehnert, M.; Salvati, M.

    2009-10-01

    We present the first results of a project, Lyman-break galaxies Stellar populations and Dynamics (LSD), aimed at obtaining spatially resolved, near-infrared (IR) spectroscopy of a complete sample of Lyman-break galaxies at z ~ 3. Deep observations with adaptive optics resulted in the detection of the main optical lines, such as [OII] λ3727, Hβ and [OIII] λ5007, which are used to study sizes, star formation rates (SFRs), morphologies, gas-phase metallicities, gas fractions and effective yields. Optical, near-IR and Spitzer/Infrared Array Camera photometry are used to measure stellar mass. We obtain that morphologies are usually complex, with the presence of several peaks of emissions and companions that are not detected in broad-band images. Typical metallicities are 10-50 per cent solar, with a strong evolution of the mass-metallicity relation from lower redshifts. Stellar masses, gas fraction and evolutionary stages vary significantly among the galaxies, with less massive galaxies showing larger fractions of gas. In contrast with observations in the local universe, effective yields decrease with stellar mass and reach solar values at the low-mass end of the sample. This effect can be reproduced by gas infall with rates of the order of the SFRs. Outflows are present but are not needed to explain the mass-metallicity relation. We conclude that a large fraction of these galaxies is actively creating stars after major episodes of gas infall or merging. Based on observations collected with European Southern Observatory/Very Large Telescope (ESO/VLT) (proposals 075.A-0300 and 076.A-0711), with the Italian TNG, operated by FGG (INAF) at the Spanish Observatorio del Roque de los Muchachos, and with the Spitzer Space Telescope, operated by JPL (Caltech) under a contract with NASA.

  16. A thermodynamic and mechanical model for the earliest Solar System: Formation via 3-d collapse of dust in the pre-Solar nebula

    NASA Astrophysics Data System (ADS)

    Criss, R. E.; Hofmeister, A.

    2012-12-01

    The fundamental and shared rotational characteristics of the Solar System (nearly circular, co-planar orbits and mostly upright axial spins of the planets) record conditions of origin, yet are not explained by prevailing 2-dimensional disk models. Current planetary spin and orbital rotational energies (R.E.) each nearly equal and linearly depend on gravitational self-potential of formation (Ug), revealing mechanical energy conservation. We derive ΔUg ˜= ΔR.E. and stability criteria from thermodynamic principles, and parlay these relationships into a detailed model of simultaneous accretion of the protoSun and planets from the dust-bearing pre-solar nebula (PSN). Gravitational heating is insignificant because Ug is negative, the 2nd law of thermodynamics must be fulfilled, and ideal gas conditions pertain until the objects were nearly fully formed. Combined conservation of angular momentum and mechanical energy during 3-dimensional collapse of spheroidal dust shells in a contracting nebula provides ΔR.E. ˜= R.E. for the central body, whereas for formation of orbiting bodies, ΔR.E.depends on the contraction of orbits during collapse. Orbital data for the inner planets follow 0.04xR.E.f ˜= -Ug which confirms conservation of angular momentum. Measured spins of the youngest stars confirm that R.E.˜= -Ug. Heat production occurs after nearly final sizes are reached via mechanisms such as shear during differential rotation and radioactivity. We focus on the dilute stage, showing that the PSN was compositionally graded due to light molecules diffusing preferentially, providing the observed planetary chemistry, and set limits on PSN mass, density, and temperature. From measured planetary masses and orbital characteristics, accounting for dissipation of spin, we deduce mechanisms and the sequence of converting a 3-d dusty cloud to the present 2-d Solar System, and infer the evolution of dust and gas densities. Duration of events is obtained from the time

  17. What can We Learn about Solar Coronal Mass Ejections, Coronal Dimmings, and Extreme-ultraviolet Jets through Spectroscopic Observations?

    NASA Astrophysics Data System (ADS)

    Tian, Hui; McIntosh, Scott W.; Xia, Lidong; He, Jiansen; Wang, Xin

    2012-04-01

    Solar eruptions, particularly coronal mass ejections (CMEs) and extreme-ultraviolet (EUV) jets, have rarely been investigated with spectroscopic observations. We analyze several data sets obtained by the EUV Imaging Spectrometer on board Hinode and find various types of flows during CMEs and jet eruptions. CME-induced dimming regions are found to be characterized by significant blueshift and enhanced line width by using a single Gaussian fit, while a red-blue (RB) asymmetry analysis and an RB-guided double Gaussian fit of the coronal line profiles indicate that these are likely caused by the superposition of a strong background emission component and a relatively weak (~10%), high-speed (~100 km s-1) upflow component. This finding suggests that the outflow velocity in the dimming region is probably of the order of 100 km s-1, not ~20 km s-1 as reported previously. These weak, high-speed outflows may provide a significant amount of mass to refill the corona after the eruption of CMEs, and part of them may experience further acceleration and eventually become solar wind streams that can serve as an additional momentum source of the associated CMEs. Density and temperature diagnostics of the dimming region suggest that dimming is primarily an effect of density decrease rather than temperature change. The mass losses in dimming regions as estimated from different methods are roughly consistent with each other, and they are 20%-60% of the masses of the associated CMEs. With the guide of RB asymmetry analysis, we also find several temperature-dependent outflows (speed increases with temperature) immediately outside the (deepest) dimming region. These outflows may be evaporation flows that are caused by the enhanced thermal conduction or nonthermal electron beams along reconnecting field lines, or induced by the interaction between the opened field lines in the dimming region and the closed loops in the surrounding plage region. In an erupted CME loop and an EUV jet

  18. 3D Simulations of Helmet Streamer Dynamics and Implications for the Slow Solar Wind

    NASA Astrophysics Data System (ADS)

    Higginson, Aleida K.; Antiochos, Spiro K.; DeVore, C. R.; Zurbuchen, Thomas H.

    2015-04-01

    The source of the slow solar wind at the Sun is still an issue of intense debate in solar and heliospheric physics. Because the majority of the solar wind observed at Earth is slow wind, understanding its origin is essential for understanding and predicting Earth’s space weather environment. In-situ and remote observations show that, when compared to the fast wind, the slow solar wind corresponds to higher freeze-in temperatures, as indicated by charge-state ratios, and more corona-like elemental abundance ratios. These results indicate that the most likely source for the slow wind is the hot plasma in the closed-field corona, but the release mechanism(s) for the wind from the closed-field regions is far from understood. We perform fully dynamic, 3D MHD simulations in order to the study the opening and closing of the Sun’s magnetic field that leads to the escape of the slow solar wind. In particular, we calculate the dynamics of helmet streamers that are driven by photospheric motions such as supergranular flows. We determine in detail the opening and closing of coronal flux, and discuss the implications of our results for theories of slow wind origin, especially the S-Web model. We also determine observational signatures for the upcoming inner heliosphere missions Solar Orbiter and Solar Probe Plus.This work was supported by the NASA SR&T and TR&T Programs.

  19. Temperature-stable and optically transparent thin-film zinc oxide aerogel electrodes as model systems for 3D interpenetrating organic-inorganic heterojunction solar cells.

    PubMed

    Krumm, Michael; Pawlitzek, Fabian; Weickert, Jonas; Schmidt-Mende, Lukas; Polarz, Sebastian

    2012-12-01

    Novel, nanostructured electrode materials comprising porous ZnO films with aerogel morphology are presented. Almost any substrate including polymers, metals, or ceramics can be coated using a method that is suitable for mass production. The thin, porous films can be prepared from the wet gels via conventional drying, supercritical drying is not necessary. The filigree ZnO network is thermally very stable and exhibits sufficient electrical conductivity for advanced electronic applications. The latter was tested by realizing a highly desired architecture of organic-inorganic hybrid solar cells. After sensitizing of the ZnO with a purely organic squarine dye (SQ2), a nanostructured, interpenetrating 3D network of the inorganic semiconductor (ZnO) and organic semiconductor (P3HT) was prepared. The solar cell device was tested under illumination with AM 1.5G solar light (100 mW/cm(2)) and exhibited an energy conversion efficiency (η(eff)) of 0.69%.

  20. Energy-Specific Solar Radiation Data from Msg: the HELIOSAT-3 Project

    NASA Astrophysics Data System (ADS)

    Schroedter-Homscheidt, M.

    2006-08-01

    Solar energy technologies such as photovoltaics, solar thermal power plants, passive solar heating/cooling systems and day lighting in buildings are expected to continue their very rapid growth. In this context the availability of reliable solar radiation data is of high economic value both for planning and operating these systems. HELIOSAT-3 aims the quantification of surface solar irradiance in cloud free and cloudy situations and additional energy-specific parameters as direct normal and diffuse irradiance over Europe and Africa using the enhanced capabilities of MSG. Emphasis is laid on clouds, water vapor, aerosols and ozone and their influence on surface solar irradiance. Several projects as e.g. the HELIOSAT-3 and PVSAT-2 European Commission FP5 and the ENVISOLAR (ESA Earth Observation Market Development Program) projects made profit from the data access and additional MSG product information obtained through the RAO program. The paper focuses on results obtained during the RAO project based on funding in HELIOSAT-3, PVSAT-2 and ENVISOLAR projects.

  1. Kepler-423b: a half-Jupiter mass planet transiting a very old solar-like star

    NASA Astrophysics Data System (ADS)

    Gandolfi, D.; Parviainen, H.; Deeg, H. J.; Lanza, A. F.; Fridlund, M.; Prada Moroni, P. G.; Alonso, R.; Augusteijn, T.; Cabrera, J.; Evans, T.; Geier, S.; Hatzes, A. P.; Holczer, T.; Hoyer, S.; Kangas, T.; Mazeh, T.; Pagano, I.; Tal-Or, L.; Tingley, B.

    2015-04-01

    We report the spectroscopic confirmation of the Kepler object of interest KOI-183.01 (Kepler-423b), a half-Jupiter mass planet transiting an old solar-like star every 2.7 days. Our analysis is the first to combine the full Kepler photometry (quarters 1-17) with high-precision radial velocity measurements taken with the FIES spectrograph at the Nordic Optical Telescope. We simultaneously modelled the photometric and spectroscopic data-sets using Bayesian approach coupled with Markov chain Monte Carlo sampling. We found that the Kepler pre-search data conditioned light curve of Kepler-423 exhibits quarter-to-quarter systematic variations of the transit depth, with a peak-to-peak amplitude of ~4.3% and seasonal trends reoccurring every four quarters. We attributed these systematics to an incorrect assessment of the quarterly variation of the crowding metric. The host star Kepler-423 is a G4 dwarf with M⋆ = 0.85 ± 0.04 M⊙, R⋆ = 0.95 ± 0.04 R⊙, Teff= 5560 ± 80 K, [M/H] = - 0.10 ± 0.05 dex, and with an age of 11 ± 2 Gyr. The planet Kepler-423b has a mass of Mp= 0.595 ± 0.081MJup and a radius of Rp= 1.192 ± 0.052RJup, yielding a planetary bulk density of ρp = 0.459 ± 0.083 g cm-3. The radius of Kepler-423b is consistent with both theoretical models for irradiated coreless giant planets and expectations based on empirical laws. The inclination of the stellar spin axis suggests that the system is aligned along the line of sight. We detected a tentative secondary eclipse of the planet at a 2σ confidence level (ΔFec = 14.2 ± 6.6 ppm) and found that the orbit might have asmall non-zero eccentricity of 0.019+0.028-0.014. With a Bond albedo of AB = 0.037 ± 0.019, Kepler-423b is one of the gas-giant planets with the lowest albedo known so far. Based on observations obtained with the Nordic Optical Telescope, operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway, and Sweden, in the Spanish Observatorio del Roque de los Muchachos of

  2. Transient heat and mass transfer analysis in a porous ceria structure of a novel solar redox reactor

    SciTech Connect

    Chandran, RB; Bader, R; Lipinski, W

    2015-06-01

    Thermal transport processes are numerically analyzed for a porous ceria structure undergoing reduction in a novel redox reactor for solar thermochemical fuel production. The cylindrical reactor cavity is formed by an array of annular reactive elements comprising the porous ceria monolith integrated with gas inlet and outlet channels. Two configurations are considered, with the reactor cavity consisting of 10 and 20 reactive elements, respectively. Temperature dependent boundary heat fluxes are obtained on the irradiated cavity wall by solving for the surface radiative exchange using the net radiation method coupled to the heat and mass transfer model of the reactive element. Predicted oxygen production rates are in the range 40-60 mu mol s(-1) for the geometries considered. After an initial rise, the average temperature of the reactive element levels off at 1660 and 1680 K for the two geometries, respectively. For the chosen reduction reaction rate model, oxygen release continues after the temperature has leveled off which indicates that the oxygen release reaction is limited by chemical kinetics and/or mass transfer rather than by the heating rate. For a fixed total mass of ceria, the peak oxygen release rate is doubled for the cavity with 20 reactive elements due to lower local oxygen partial pressure. (C) 2015 Elsevier Masson SAS. All rights reserved.

  3. Effects of the LBV Primary's Mass-loss Rate on the 3D Hydrodynamics of eta Carinae's Colliding Winds

    NASA Technical Reports Server (NTRS)

    Madura, Thomas I.; Gull, Theodore R.; Cocoran, M.; Okazaki, A.; Owocki, S.; Russell, C.; Hamaguchi, K.; Clementel, N; Groh, J.; Hillier, D. J.

    2013-01-01

    At the heart of eta Carinae's spectacular "Homunculus" nebula lies an extremely luminous (L(sub Total) greater than approximately 5 × 10(exp 6) solar luminosity) colliding wind binary with a highly eccentric (e approximately 0.9), 5.54-year orbit (Figure 1). The primary of the system, a Luminous Blue Variable (LBV), is our closest (D approximately 2.3 kpc) and best example of a pre-hypernova or pre-gamma ray burst environment. The remarkably consistent and periodic RXTE X-ray light curve surprisingly showed a major change during the system's last periastron in 2009, with the X-ray minimum being approximately 50% shorter than the minima of the previous two cycles1. Between 1998 and 2011, the strengths of various broad stellar wind emission lines (e.g. Halpha, Fe II) in line-of-sight (l.o.s.) also decreased by factors of 1.5 - 3 relative to the continuum2. The current interpretation for these changes is that they are due to a gradual factor of 2 - 4 drop in the primary's mass-loss rate over the last approximately 15 years1, 2. However, while a secular change is seen for a direct view of the central source, little to no change is seen in profiles at high stellar latitudes or reflected off of the dense, circumbinary material known as the "Weigelt blobs"2, 3. Moreover, model spectra generated with CMFGEN predict that a factor of 2 - 4 drop in the primary's mass-loss rate should lead to huge changes in the observed spectrum, which thus far have not been seen. Here we present results from large- (plus or minus 1620 AU) and small- (plus or minus 162 AU) domain, full 3D smoothed particle hydrodynamics (SPH) simulations of eta Car's massive binary colliding winds for three different primary-star mass-loss rates (2.4, 4.8, and 8.5 × 10(exp -4) solar mass/yr). The goal is to investigate how the mass-loss rate affects the 3D geometry and dynamics of eta Car's optically-thick wind and spatially-extended wind-wind collision (WWC) regions, both of which are known sources of

  4. Solar wind research with the Large Angle Spectroscopic Coronagraph (LASCO) experiment onboard the Solar and Heliospheric Observatory (SOHO) satellite

    NASA Technical Reports Server (NTRS)

    Brueckner, G. E.

    1995-01-01

    The ESA-NASA satellite, to be launched in October 1995, carries three nested coronagraphs, which will image the solar corona from 1.1 R(solar mass) to 30 R(solar mass). Super polished mirrors have been developed for the design of a mirror Lyot coronagraph which has a straylight level comparable with the coronal intensity from 1.1 R, to 30 R(solar mass) Coronal details can be imaged with a spatial resolution of 6 arc seconds. A Fabry Perot interferometer with a spectral resolution of 0.7 A at the wavelength of the green coronal emission line will allow the simultaneous construction of spectra over the entire field of view of 10(exp 6) pixels. The middle coronagraph (1.5 R(solar mass) - 6 R(solar mass)) and the outer coronagraph (3 R(solar mass) - 30 R(solar mass)) are externally occulted lens Lyot coronagraphs. Their straylight level 10(exp -11) B(solar mass) and 10(exp -12) B(solar mass) respectively is an order of magnitude smaller than the intensity of the corona. The sensitivity of LASCO to distinguish between different solar wind acceleration mechanisms will be discussed as well as its ability to discern different CME models.

  5. WISEA J114724.10-204021.3: A Free-floating Planetary Mass Member of the TW Hya Association

    NASA Astrophysics Data System (ADS)

    Schneider, Adam C.; Windsor, James; Cushing, Michael C.; Kirkpatrick, J. Davy; Wright, Edward L.

    2016-05-01

    We present WISEA J114724.10-204021.3, a young, low-mass, high-probability member of the TW Hya association (TWA). WISEA J114724.10-204021.3 was discovered based on its red AllWISE color (W1 - W2 = 0.63 mag) and extremely red 2MASS J - K S color (>2.64 mag), the latter of which is confirmed with near-infrared photometry from the Visible and Infrared Survey Telescope for Astronomy Hemisphere Survey (J - K S = 2.57 ± 0.03). Follow-up near-infrared spectroscopy shows a spectral type of L7 ± 1 as well as several spectroscopic indicators of youth. These include a peaked H-band shape and a steeper K-band slope, traits typically attributed to low surface gravity. The sky position, proper motion, and distance estimates of WISEA J114724.10-204021.3 are all consistent with membership in the ˜10 Myr old TWA. Using the age of the TWA and evolutionary models, we estimate the mass of WISEA J114724.10-204021.3 to be 5-13 M Jup, making it one of the youngest and lowest-mass free-floating objects yet discovered in the Solar neighborhood.

  6. The 3rd Joint Solar Dynamics Project data summary: Solar magnetic field, chromospheric and coronal observations near the time of the 18 March 1988 solar eclipse

    NASA Astrophysics Data System (ADS)

    Sime, D. G.; Garcia, C. J.; Lundin, W. E.; Yasukawa, E. A.; Mickey, D. L.; Labonte, B.

    1988-11-01

    The general goal of the HAO/University of Hawaii Joint Solar Dynamics Project is to establish the relationships that exist between the solar magnetic field which is detected in the photosphere and the structure and evolution of the corona. The SOLDYN programs of 1982 and 1983 demonstrated the ability to use existing instruments to gather data of value in the pursuit of that goal. The goals for the observations in 1988 are as follows: (1) Document the state of the sun, from the photosphere up through the chromosphere and out into the corona for the approximately four-week interval around the total solar eclipse of 18 March 1988, and (2) Identify the relationship between the photospheric magnetic fields and the temperature and density structure of the corona. The reduced observations made during this SOLDYN 3 period necessary to achieve these goals are provided. The observations are presented both in the form of daily photographic and photo-electric measurements, and in synoptic format for the period.

  7. Solar Irradiance observation from Fengyun3 meteorological satellites: recent results and future plan

    NASA Astrophysics Data System (ADS)

    Qi, Jin; Zhang, Peng; Qiu, Hong; Fang, Wei

    2016-04-01

    The Solar Irradiance Monitors (SIM) on-board Fengyun3 (FY3) satellites have been observing Total Solar Irradiance since June 2008. With the lessons from the first two satellites, the SIM on FY3C has two significant improvements by adding sun tracing system and temperature control system, which is named after SIM-II. The SIM-II measurements are first really traceable to World Radiometric Reference and building an on-orbit aging model. TSI from FY3C/SIM-II has been evaluated by comparing with SORCE/TIM and RMIB composite data. The result shows a good consistency. Monitoring of strong solar activity during Oct. 2014, FY3C/SIM-II and SORCE/TIM showed the similar result about solar energy change. For the future plan, we would like to have cooperation with RMIB and PMOD on TSI observation from FY3 early-morning orbit satellite which is designed to launch in 2018. We also plan to develop a new ability to capture daily variance in solar spectral irradiance on the early-morning orbit.

  8. The Controlling Mechanism for Potential Loss in CH 3 NH 3 PbBr 3 Hybrid Solar Cells

    SciTech Connect

    Zheng, Xiaojia; Chen, Bo; Yang, Mengjin; Wu, Congcong; Orler, Bruce; Moore, Robert B.; Zhu, Kai; Priya, Shashank

    2016-08-12

    We investigated moisture and thermal stability of MAPbBr3 perovskite material. Cubic MAPbBr3 was found to be moisture-insensitive and can avoid the thermal stability issues introduced by low-temperature phase transition in MAPbI3. MAPbBr3 and MAPbI3 hybrid solar cells with efficiencies of ~7.1% and ~15.5%, respectively, were fabricated, and we identified the correlation between the working temperature, light intensity, and the photovoltaic performance. No charge-carrier transport barriers were found in the MAPbBr3 and MAPbI3 solar cells. The MAPbBr3 solar cell displays a better stability under high working temperature because of its close-packed crystal structure. Temperature-dependent photocurrent-voltage characteristics indicate that, unlike the MAPbI3 solar cell with an activation energy (EA) nearly equal to its band gap (Eg), the EA for the MAPbBr3 solar cell is much lower than its Eg. This indicates that a high interface recombination process limits the photovoltage and consequently the device performance of the MAPbBr3 solar cell.

  9. Supernova progenitor stars in the initial range of 23 to 33 solar masses and their relation with the SNR Cassiopeia A

    NASA Astrophysics Data System (ADS)

    Pérez-Rendón, B.; García-Segura, G.; Langer, N.

    2009-11-01

    Context: Multi wavelength observations of Cassiopeia A (Cas A) have provided us with strong evidence of circumstellar material surrounding the progenitor star. It has been suggested that its progenitor was a massive star with strong mass loss. But, despite the large amount of observational data from optical, IR, radio, and x-ray observations, the identity of Cas A progenitor is still elusive. Aims: In this work, we computed stellar and circumstellar numerical models to look for the progenitor of Cas A. The models are compared with the observational constraints that come from chemical observed abundances and dynamical information. Methods: We first computed stellar evolution models to get time-dependent wind parameters and surface abundances using the code STERN. To explore the range of masses proposed by several previous works, we chose a set of probable progenitor stars with initial masses of 23, 28, 29, 30, and 33 M⊙, with initial solar composition (Y=0.28, Z=0.02) and mass loss. The derived mass loss rates and wind terminal velocities are used as inner boundary conditions in the explicit, hydrodynamical code ZEUS-3D to simulate the evolution of the circumstellar medium. We simplified the calculations by using one-dimensional grids in the main sequence and red super-giant (RSG) stages, and two-dimensional grids for the post-RSG evolution and supernova (SN) blast wave. Results: Our stellar set gives distinct SN progenitors: RSG, luminous blue super giants (LBSGs), and Wolf-Rayet (WR) stars. We named these type of stars “luminous blue super giant” (LBSGs) to distinguish them from normal blue super giants (BSGs) of much lower initial masses. The 23 M⊙ star explodes as an RSG in a ρ ˜ r-2 dense, free-streaming wind surrounded by a thin, compressed, RSG shell. The 28 M⊙ star explodes as an LBSG, and the SN blast wave interacts with a low density, free streaming wind surrounded by an unstable and massive “RSG+LBSG” shell. Finally, the 30 and 33 M

  10. Photodegradation of ethyl paraben using simulated solar radiation and Ag3PO4 photocatalyst.

    PubMed

    Frontistis, Zacharias; Antonopoulou, Maria; Petala, Athanasia; Venieri, Danae; Konstantinou, Ioannis; Kondarides, Dimitris I; Mantzavinos, Dionissios

    2017-02-05

    In this work, the solar light-induced photocatalytic degradation of ethyl paraben (EP), a representative of the parabens family, was studied using silver orthophosphate, a relatively new photocatalytic material. The catalyst was synthesized by a precipitation method and had a primary crystallite size of ca 70nm, specific surface area of 1.4m(2)/g and a bandgap of 2.4eV. A factorial design methodology was implemented to evaluate the importance of EP concentration (500-1500μg/L), catalyst concentration (100-500mg/L), reaction time (4-30min), water matrix (pure water or 10mg/L humic acid) and initial solution pH (3-9) on EP removal. All individual effects but solution pH were statistically significant and so were the second-order interactions of EP concentration with reaction time or catalyst concentration. The water matrix effect was negative (all other effects were positive) signifying the role of humic acid as scavenger of the oxidant species. Liquid chromatography-time of flight mass spectrometry revealed the formation of methyl paraben, 4-hydroxybenzoic acid, benzoic acid and phenol as primary transformation by-products; these are formed through dealkylation and decarboxylation reactions initiated primarily by the photogenerated holes. Estrogenicity assays showed that methyl paraben was more estrogenic than EP; however, parabens are slightly estrogenic compared to 17β-estradiol.

  11. Combined Multipoint Remote and in situ Observations of the Asymmetric Evolution of a Fast Solar Coronal Mass Ejection

    NASA Astrophysics Data System (ADS)

    Rollett, T.; Möstl, C.; Temmer, M.; Frahm, R. A.; Davies, J. A.; Veronig, A. M.; Vršnak, B.; Amerstorfer, U. V.; Farrugia, C. J.; Žic, T.; Zhang, T. L.

    2014-07-01

    We present an analysis of the fast coronal mass ejection (CME) of 2012 March 7, which was imaged by both STEREO spacecraft and observed in situ by MESSENGER, Venus Express, Wind, and Mars Express. Based on detected arrivals at four different positions in interplanetary space, it was possible to strongly constrain the kinematics and the shape of the ejection. Using the white-light heliospheric imagery from STEREO-A and B, we derived two different kinematical profiles for the CME by applying the novel constrained self-similar expansion method. In addition, we used a drag-based model to investigate the influence of the ambient solar wind on the CME's propagation. We found that two preceding CMEs heading in different directions disturbed the overall shape of the CME and influenced its propagation behavior. While the Venus-directed segment underwent a gradual deceleration (from ~2700 km s-1 at 15 R ⊙ to ~1500 km s-1 at 154 R ⊙), the Earth-directed part showed an abrupt retardation below 35 R ⊙ (from ~1700 to ~900 km s-1). After that, it was propagating with a quasi-constant speed in the wake of a preceding event. Our results highlight the importance of studies concerning the unequal evolution of CMEs. Forecasting can only be improved if conditions in the solar wind are properly taken into account and if attention is also paid to large events preceding the one being studied.

  12. Direct evidence of an eruptive, filament-hosting magnetic flux rope leading to a fast solar coronal mass ejection

    SciTech Connect

    Chen, Bin; Gary, D. E.; Bastian, T. S.

    2014-10-20

    Magnetic flux ropes (MFRs) are believed to be at the heart of solar coronal mass ejections (CMEs). A well-known example is the prominence cavity in the low corona that sometimes makes up a three-part white-light (WL) CME upon its eruption. Such a system, which is usually observed in quiet-Sun regions, has long been suggested to be the manifestation of an MFR with relatively cool filament material collecting near its bottom. However, observational evidence of eruptive, filament-hosting MFR systems has been elusive for those originating in active regions. By utilizing multi-passband extreme-ultraviolet (EUV) observations from Solar Dynamics Observatory/Atmospheric Imaging Assembly, we present direct evidence of an eruptive MFR in the low corona that exhibits a hot envelope and a cooler core; the latter is likely the upper part of a filament that undergoes a partial eruption, which is later observed in the upper corona as the coiled kernel of a fast, WL CME. This MFR-like structure exists more than 1 hr prior to its eruption, and displays successive stages of dynamical evolution, in which both ideal and non-ideal physical processes may be involved. The timing of the MFR kinematics is found to be well correlated with the energy release of the associated long-duration C1.9 flare. We suggest that the long-duration flare is the result of prolonged energy release associated with the vertical current sheet induced by the erupting MFR.

  13. The Relation between Coronal Holes and Coronal Mass Ejections during the Rise, Maximum, and Declining Phases of Solar Cycle 23

    NASA Technical Reports Server (NTRS)

    Mohamed, A. A.; Gopalswamy, N; Yashiro, S.; Akiyama, S.; Makela, P.; Xie, H.; Jung, H.

    2012-01-01

    We study the interaction between coronal holes (CHs) and coronal mass ejections (CMEs) using a resultant force exerted by all the coronal holes present on the disk and is defined as the coronal hole influence parameter (CHIP). The CHIP magnitude for each CH depends on the CH area, the distance between the CH centroid and the eruption region, and the average magnetic field within the CH at the photospheric level. The CHIP direction for each CH points from the CH centroid to the eruption region. We focus on Solar Cycle 23 CMEs originating from the disk center of the Sun (central meridian distance =15deg) and resulting in magnetic clouds (MCs) and non-MCs in the solar wind. The CHIP is found to be the smallest during the rise phase for MCs and non-MCs. The maximum phase has the largest CHIP value (2.9 G) for non-MCs. The CHIP is the largest (5.8 G) for driverless (DL) shocks, which are shocks at 1 AU with no discernible MC or non-MC. These results suggest that the behavior of non-MCs is similar to that of the DL shocks and different from that of MCs. In other words, the CHs may deflect the CMEs away from the Sun-Earth line and force them to behave like limb CMEs with DL shocks. This finding supports the idea that all CMEs may be flux ropes if viewed from an appropriate vantage point.

  14. An estimate of the coronal magnetic field near a solar coronal mass ejection from low-frequency radio observations

    SciTech Connect

    Hariharan, K.; Ramesh, R.; Kishore, P.; Kathiravan, C.; Gopalswamy, N.

    2014-11-01

    We report ground-based, low-frequency (<100 MHz) radio imaging, spectral, and polarimeter observations of the type II radio burst associated with the solar coronal mass ejection (CME) that occurred on 2013 May 2. The spectral observations indicate that the burst has fundamental (F) and harmonic (H) emission components with split-band and herringbone structures. The imaging observations at 80 MHz indicate that the H component of the burst was located close to leading edge of the CME at a radial distance of r ≈ 2 R {sub ☉} in the solar atmosphere. The polarimeter observations of the type II burst, also at 80 MHz, indicate that the peak degree of circular polarization (dcp) corresponding to the emission generated in the corona ahead of and behind the associated MHD shock front are ≈0.05 ± 0.02 and ≈0.1 ± 0.01, respectively. We calculated the magnetic field B in the above two coronal regions by adopting the empirical relationship between the dcp and B for the harmonic plasma emission and the values are ≈(0.7-1.4) ± 0.2 G and ≈(1.4-2.8) ± 0.1 G, respectively.

  15. A HIGH-FREQUENCY TYPE II SOLAR RADIO BURST ASSOCIATED WITH THE 2011 FEBRUARY 13 CORONAL MASS EJECTION

    SciTech Connect

    Cho, K.-S.; Kim, R.-S.; Gopalswamy, N.; Kwon, R.-Y.; Yashiro, S.

    2013-03-10

    We examine the relationship between the high-frequency (425 MHz) type II radio burst and the associated white-light coronal mass ejection (CME) that occurred on 2011 February 13. The radio burst had a drift rate of 2.5 MHz s{sup -1}, indicating a relatively high shock speed. From SDO/AIA observations we find that a loop-like erupting front sweeps across high-density coronal loops near the start time of the burst (17:34:17 UT). The deduced distance of shock formation (0.06 Rs) from the flare center and speed of the shock (1100 km s{sup -1}) using the measured density from SDO/AIA observations are comparable to the height (0.05 Rs, from the solar surface) and speed (700 km s{sup -1}) of the CME leading edge observed by STEREO/EUVI. We conclude that the type II burst originates even in the low corona (<59 Mm or 0.08 Rs, above the solar surface) due to the fast CME shock passing through high-density loops.

  16. Evidence from stable isotopes and (10)Be for solar system formation triggered by a low-mass supernova.

    PubMed

    Banerjee, Projjwal; Qian, Yong-Zhong; Heger, Alexander; Haxton, W C

    2016-11-22

    About 4.6 billion years ago, some event disturbed a cloud of gas and dust, triggering the gravitational collapse that led to the formation of the solar system. A core-collapse supernova, whose shock wave is capable of compressing such a cloud, is an obvious candidate for the initiating event. This hypothesis can be tested because supernovae also produce telltale patterns of short-lived radionuclides, which would be preserved today as isotopic anomalies. Previous studies of the forensic evidence have been inconclusive, finding a pattern of isotopes differing from that produced in conventional supernova models. Here we argue that these difficulties either do not arise or are mitigated if the initiating supernova was a special type, low in mass and explosion energy. Key to our conclusion is the demonstration that short-lived (10)Be can be readily synthesized in such supernovae by neutrino interactions, while anomalies in stable isotopes are suppressed.

  17. Coronal mass ejection and solar flare initiation processes without appreciable changes of the large-scale magnetic field topology

    NASA Astrophysics Data System (ADS)

    Veselovsky, I. S.; Panasenco, O. A.

    We demonstrate that spurious three-dimensional re-constructions from two-dimensional images and movies of solar flares and coronal mass ejections can arise as a result of viewing conditions and projection effects, which are not always properly taken into account in the current literature. Theory and observations indicate that eruptions can proceed with or without large-scale topological changes of prominences and coronal magnetic fields. Electric currents and plasma drifts in crossed electric and magnetic fields play not negligible, but important role. This means that large-scale magnetic reconnections understood as topological transitions in the magnetic field are not always necessary for eruptions. The scenario of expanding and rising non-planar systems of preexisting loops and arcades, which are deforming when shearing at bottom parts, twisting and rotating at summits, satisfactory fits available observations. Movies are presented demonstrating this type of behavior with a preserved magnetic connectivity.

  18. The evolution of rotating stars. I - Method and exploratory calculations for a 7-solar-mass star

    NASA Technical Reports Server (NTRS)

    Endal, A. S.; Sofia, S.

    1976-01-01

    A method is developed which allows the evolution of rotating stars to be studied well beyond the main-sequence stage. Four different cases of redistribution of angular momentum in an evolving star are considered. Evolutionary sequences for a 7-solar-mass star, rotating according to these different cases, were computed from the zero-age main-sequence to the double-shell-source stage. Each sequence was begun with a (typical) equatorial rotational velocity of 210 km/s. On the main sequence, the effects of rotation are of minor importance. However, as the core contracts during later stages, important effects arise in all physically plausible cases. The outer regions of the cores approach critical velocities and develop unstable angular-velocity distributions. The effects of these instabilities should significantly alter the subsequent evolution.

  19. Evidence from stable isotopes and 10Be for solar system formation triggered by a low-mass supernova

    PubMed Central

    Banerjee, Projjwal; Qian, Yong-Zhong; Heger, Alexander; Haxton, W C

    2016-01-01

    About 4.6 billion years ago, some event disturbed a cloud of gas and dust, triggering the gravitational collapse that led to the formation of the solar system. A core-collapse supernova, whose shock wave is capable of compressing such a cloud, is an obvious candidate for the initiating event. This hypothesis can be tested because supernovae also produce telltale patterns of short-lived radionuclides, which would be preserved today as isotopic anomalies. Previous studies of the forensic evidence have been inconclusive, finding a pattern of isotopes differing from that produced in conventional supernova models. Here we argue that these difficulties either do not arise or are mitigated if the initiating supernova was a special type, low in mass and explosion energy. Key to our conclusion is the demonstration that short-lived 10Be can be readily synthesized in such supernovae by neutrino interactions, while anomalies in stable isotopes are suppressed. PMID:27873999

  20. Evidence from stable isotopes and 10Be for solar system formation triggered by a low-mass supernova

    NASA Astrophysics Data System (ADS)

    Banerjee, Projjwal; Qian, Yong-Zhong; Heger, Alexander; Haxton, W. C.

    2016-11-01

    About 4.6 billion years ago, some event disturbed a cloud of gas and dust, triggering the gravitational collapse that led to the formation of the solar system. A core-collapse supernova, whose shock wave is capable of compressing such a cloud, is an obvious candidate for the initiating event. This hypothesis can be tested because supernovae also produce telltale patterns of short-lived radionuclides, which would be preserved today as isotopic anomalies. Previous studies of the forensic evidence have been inconclusive, finding a pattern of isotopes differing from that produced in conventional supernova models. Here we argue that these difficulties either do not arise or are mitigated if the initiating supernova was a special type, low in mass and explosion energy. Key to our conclusion is the demonstration that short-lived 10Be can be readily synthesized in such supernovae by neutrino interactions, while anomalies in stable isotopes are suppressed.

  1. Enhanced Charge Separation in Ternary P3HT/PCBM/CuInS2 Nanocrystals Hybrid Solar Cells

    PubMed Central

    Lefrançois, Aurélie; Luszczynska, Beata; Pepin-Donat, Brigitte; Lombard, Christian; Bouthinon, Benjamin; Verilhac, Jean-Marie; Gromova, Marina; Faure-Vincent, Jérôme; Pouget, Stéphanie; Chandezon, Frédéric; Sadki, Saïd; Reiss, Peter

    2015-01-01

    Geminate recombination of bound polaron pairs at the donor/acceptor interface is one of the major loss mechanisms in organic bulk heterojunction solar cells. One way to overcome Coulomb attraction between opposite charge carriers and to achieve their full dissociation is the introduction of high dielectric permittivity materials such as nanoparticles of narrow band gap semiconductors. We selected CuInS2 nanocrystals of 7.4 nm size, which present intermediate energy levels with respect to poly(3-hexylthiophene) (P3HT) and Phenyl-C61-butyric acid methyl ester (PCBM). Efficient charge transfer from P3HT to nanocrystals takes place as evidenced by light-induced electron spin resonance. Charge transfer between nanocrystals and PCBM only occurs after replacing bulky dodecanethiol (DDT) surface ligands with shorter 1,2-ethylhexanethiol (EHT) ligands. Solar cells containing in the active layer a ternary blend of P3HT:PCBM:CuInS2-EHT nanocrystals in 1:1:0.5 mass ratio show strongly improved short circuit current density and a higher fill factor with respect to the P3HT:PCBM reference device. Complementary measurements of the absorption properties, external quantum efficiency and charge carrier mobility indicate that enhanced charge separation in the ternary blend is at the origin of the observed behavior. The same trend is observed for blends using the glassy polymer poly(triarylamine) (PTAA). PMID:25588811

  2. Enhanced Charge Separation in Ternary P3HT/PCBM/CuInS2 Nanocrystals Hybrid Solar Cells

    NASA Astrophysics Data System (ADS)

    Lefrançois, Aurélie; Luszczynska, Beata; Pepin-Donat, Brigitte; Lombard, Christian; Bouthinon, Benjamin; Verilhac, Jean-Marie; Gromova, Marina; Faure-Vincent, Jérôme; Pouget, Stéphanie; Chandezon, Frédéric; Sadki, Saïd; Reiss, Peter

    2015-01-01

    Geminate recombination of bound polaron pairs at the donor/acceptor interface is one of the major loss mechanisms in organic bulk heterojunction solar cells. One way to overcome Coulomb attraction between opposite charge carriers and to achieve their full dissociation is the introduction of high dielectric permittivity materials such as nanoparticles of narrow band gap semiconductors. We selected CuInS2 nanocrystals of 7.4 nm size, which present intermediate energy levels with respect to poly(3-hexylthiophene) (P3HT) and Phenyl-C61-butyric acid methyl ester (PCBM). Efficient charge transfer from P3HT to nanocrystals takes place as evidenced by light-induced electron spin resonance. Charge transfer between nanocrystals and PCBM only occurs after replacing bulky dodecanethiol (DDT) surface ligands with shorter 1,2-ethylhexanethiol (EHT) ligands. Solar cells containing in the active layer a ternary blend of P3HT:PCBM:CuInS2-EHT nanocrystals in 1:1:0.5 mass ratio show strongly improved short circuit current density and a higher fill factor with respect to the P3HT:PCBM reference device. Complementary measurements of the absorption properties, external quantum efficiency and charge carrier mobility indicate that enhanced charge separation in the ternary blend is at the origin of the observed behavior. The same trend is observed for blends using the glassy polymer poly(triarylamine) (PTAA).

  3. Modeling of downconverter based on Pr3+-Yb3+ codoped fluoride glasses to improve sc-Si solar cells efficiency

    NASA Astrophysics Data System (ADS)

    Song, P.; Jiang, C.

    2012-12-01

    Quantum cutting via a two-step resonant energy transfer in a spectral downconverter of Pr3+-Yb3+ codoped fluoride glass is investigated numerically by proposing up and solving the theoretical model of rate equations and power propagation equations. Based on the optimal Pr3+-Yb3+ concentration and the thickness of the spectral downconverter, the total power conversion efficiency of 175% and total quantum conversion efficiency of 186% are obtained. The performance of a sc-Si solar cell covered with a spectral downconverter is evaluated with the photovoltaic simulation programme PC1D. For sc-Si solar cells, the energy conversion efficiency of 14.90% for the modified AM1.5G compared to a 12.25% energy conversion efficiency for the standard AM1.5G has been obtained, and the simulated relative energy conversion efficiency for the sc-Si solar cell approaches up to 1.21. Our results show that the use of a spectral downconverter yields better sc-Si solar cell performance compared to the standard AM1.5G irradiation. The paper also provides a framework for investigating and optimizing the rare-earth doped spectral downconverter, potentially enabling a sc-Si solar cell with an efficiency improvement.

  4. A Search for Transiting Neptune-Mass Extrasolar Planets in High-Precision Photometry of Solar-Type Stars

    NASA Technical Reports Server (NTRS)

    Henry, Stephen M.; Gillman, Amelie r.; Henry, Gregory W.

    2005-01-01

    Tennessee State University operates several automatic photometric telescopes (APTs) at Fairborn Observatory in southern Arizona. Four 0.8 m APTs have been dedicated to measuring subtle luminosity variations that accompany magnetic cycles in solar-type stars. Over 1000 program and comparison stars have been observed every clear night in this program for up to 12 years with a precision of approximately 0.0015 mag for a single observation. We have developed a transit-search algorithm, based on fitting a computed transit template for each trial period, and have used it to search our photometric database for transits of unknown companions. Extensive simulations with the APT data have shown that we can reliably recover transits with periods under 10 days as long as the transits have a depth of at least 0.0024 mag, or about 1.6 times the scatter in the photometric observations. Thus, due to our high photometric precision, we are sensitive to transits of possible short-period Neptune-mass planets that likely would have escaped detection by current radial velocity techniques. Our search of the APT data sets for 1087 program and comparison stars revealed no new transiting planets. However, the detection of several unknown grazing eclipsing binaries from among our comparison stars, with eclipse depths of only a few millimags, illustrates the success of our technique. We have used this negative result to place limits on the frequency of Neptune-mass planets in close orbits around solar-type stars in the Sun's vicinity.

  5. Full Printable Processed Mesoscopic CH3NH3PbI3/TiO2 Heterojunction Solar Cells with Carbon Counter Electrode

    PubMed Central

    Ku, Zhiliang; Rong, Yaoguang; Xu, Mi; Liu, Tongfa; Han, Hongwei

    2013-01-01

    A mesoscopic methylammonium lead iodide (CH3NH3PbI3) perovskite/TiO2 heterojunction solar cell is developed with low-cost carbon counter electrode (CE) and full printable process. With carbon black/spheroidal graphite CE, this mesoscopic heterojunction solar cell presents high stability and power conversion efficiency of 6.64%, which is higher than that of the flaky graphite based device and comparable to the conventional Au version. PMID:24185501

  6. A Simple Sb2Te3 Back-Contact Process for CdTe Solar Cells

    NASA Astrophysics Data System (ADS)

    Siepchen, B.; Späth, B.; Drost, C.; Krishnakumar, V.; Kraft, C.; Winkler, M.; König, J.; Bartholomé, K.; Peng, S.

    2015-10-01

    CdTe solar technology has proved to be a cost-efficient solution for energy production. Formation of the back contact is an important and critical step in preparing high-efficiency, stable CdTe solar cells. In this paper we report a simple CdTe solar cell (Sb2Te3) back contact-formation process. The CdS and CdTe layers were deposited by close-space sublimation. After CdCl2 annealing treatment, the CdTe surface was etched by use of a mixture of nitric and phosphoric acids to obtain a Te-rich surface. Elemental Sb was sputtered on the etched surface and successive post-annealing treatment induced Sb2Te3 alloy formation. Structural characterization by x-ray diffraction analysis confirmed formation of the Sb2Te3 phase. The performance of solar cells with nanoalloyed Sb2Te3 back contacts was comparable with that of reference solar cells prepared with sputtered Sb2Te3 back contact from a compound sputter target.

  7. Optical simulations of P3HT/Si nanowire array hybrid solar cells.

    PubMed

    Wang, Wenbo; Li, Xinhua; Wen, Long; Zhao, Yufeng; Duan, Huahua; Zhou, Bukang; Shi, Tongfei; Zeng, Xuesong; Li, Ning; Wang, Yuqi

    2014-01-01

    An optical simulation of poly(3-hexylthiophene) (P3HT)/Si nanowire array (NWA) hybrid solar cells was investigated to evaluate the optical design requirements of the system by using finite-difference time-domain (FDTD) method. Steady improvement of light absorption was obtained with increased P3HT coating shell thickness from 0 to 80 nm on Si NWA. Further increasing the thickness caused dramatic decrease of the light absorption. Combined with the analysis of ultimate photocurrents, an optimum geometric structure with a coating P3HT thickness of 80 nm was proposed. At this structure, the hybrid solar cells show the most efficient light absorption. The optimization of the geometric structure and further understanding of the optical characteristics may contribute to the development for the practical experiment of the promising hybrid solar cells.

  8. The effects of dual-domain mass transfer on the tritium-helium-3 dating method.

    PubMed

    Neumann, Rebecca B; Labolle, Eric M; Harvey, Charles F

    2008-07-01

    Diffusion of tritiated water (referred to as tritium) and helium-3 between mobile and immobile regions in aquifers (mass transfer) can affect tritium and helium-3 concentrations and hence tritium-helium-3 (3H/3He) ages that are used to estimate aquifer recharge and groundwater residence times. Tritium and helium-3 chromatographically separate during transport because their molecular diffusion coefficients differ. Simulations of tritium and helium-3 transport and diffusive mass transfer along stream tubes show that mass transfer can shift the 3H/3He age of the tritium and helium-3 concentration ([3H + 3He]) peak to dates much younger than the 1963 peak in atmospheric tritium. Furthermore, diffusive mass-transfer can cause the 3H/3He age to become younger downstream along a stream tube, even as the mean water-age must increase. Simulated patterns of [3H + 3He] versus 3H/3He age using a mass transfer model appear consistent with a variety of field data. These results suggest that diffusive mass transfer should be considered, especially when the [3H + 3He] peak is not well defined or appears younger than the atmospheric peak. 3H/3He data provide information about upstream mass-transfer processes that could be used to constrain mass-transfer models; however, uncritical acceptance of 3H/3He dates from aquifers with immobile regions could be misleading.

  9. Organic solar cells: evaluation of the stability of P3HT using time-delayed degradation

    NASA Astrophysics Data System (ADS)

    Poh, Chung-How; Poh, Chung-Kiak; Bryant, Glenn; Belcher, Warwick; Dastoor, Paul

    2011-12-01

    Despite the fact that the performance of organic solar cells is generally susceptible to degradation by moisture exposure, there has been suggestion that the photoactive layer (P3HT) is surprisingly resilient. This work attempts to confirm the stability of P3HT as an organic solar cell material by deliberately introducing water into the photoactive layer. A dramatic step drop in device performance during cell characterization is observed approximately one day after the device has been fabricated. The time-delayed step drop in output efficiency strongly suggests that moisture has little effect on the P3HT conducting polymer.

  10. Fitting a 3-D analytic model of the coronal mass ejection to observations

    NASA Technical Reports Server (NTRS)

    Gibson, S. E.; Biesecker, D.; Fisher, R.; Howard, R. A.; Thompson, B. J.

    1997-01-01

    The application of an analytic magnetohydrodynamic model is presented to observations of the time-dependent explusion of 3D coronal mass ejections (CMEs) out of the solar corona. This model relates the white-light appearance of the CME to its internal magnetic field, which takes the form of a closed bubble, filled with a partly anchored, twisted magnetic flux rope and embedded in an otherwise open background field. The density distribution frozen into the expanding CME expanding field is fully 3D, and can be integrated along the line of sight to reproduce observations of scattered white light. The model is able to reproduce the three conspicuous features often associated with CMEs as observed with white-light coronagraphs: a surrounding high-density region, an internal low-density cavity, and a high-density core. The model also describes the self-similar radial expansion of these structures. By varying the model parameters, the model can be fitted directly to observations of CMEs. It is shown how the model can quantitatively match the polarized brightness contrast of a dark cavity emerging through the lower corona as observed by the HAO Mauna Loa K-coronameter to within the noise level of the data.

  11. Mass independent sulfur isotope signatures in CMs: Implications for sulfur chemistry in the early solar system

    NASA Astrophysics Data System (ADS)

    Labidi, J.; Farquhar, J.; Alexander, C. M. O.'D.; Eldridge, D. L.; Oduro, H.

    2017-01-01

    We have investigated the quadruple sulfur isotopic composition of inorganic sulfur-bearing phases from 13 carbonaceous chondrites of CM type. Our samples include 4 falls and 9 Antarctic finds. We extracted sulfur from sulfides, sulfates, and elemental sulfur (S0) from all samples. On average, we recover a bulk sulfur (S) content of 2.11 ± 0.39 wt.% S (1σ). The recovered sulfate, S0 and sulfide contents represent 25 ± 12%, 10 ± 7% and 65 ± 15% of the bulk S, respectively (all 1σ). There is no evidence for differences in the bulk S content between falls and finds, and there is no correlation between the S speciation and the extent of aqueous alteration. We report ranges of Δ33S and Δ36S values in CMs that are significantly larger than previously observed. The largest variations are exhibited by S0, with Δ33S values ranging between -0.104 ± 0.012‰ and +0.256 ± 0.018‰ (2σ). The Δ36S/33S ratios of S0 are on average -3.1 ± 1.0 (2σ). Two CMs show distinct Δ36S/33S ratios, of +1.3 ± 0.1 and +0.9 ± 0.1. We suggest that these mass independent S isotopic compositions record H2S photodissociation in the nebula. The varying Δ36S/Δ33S ratios are interpreted to reflect photodissociation that occurred at different UV wavelengths. The preservation of these isotopic features requires that the S-bearing phases were heterogeneously accreted to the CM parent body. Non-zero Δ33S values are also preserved in sulfide and sulfate, and are positively correlated with S0 values. This indicates a genetic relationship between the S-bearing phases: We argue that sulfates were produced by the direct oxidation of S0 (not sulfide) in the parent body. We describe two types of models that, although imperfect, can explain the major features of the CM S isotope compositions, and can be tested in future studies. Sulfide and S0 could both be condensates from the nebula, as the residue and product, respectively, of incomplete H2S photodissociation by UV light (wavelength <150 nm

  12. High efficiency CH3NH3PbI3:CdS perovskite solar cells with CuInS2 as the hole transporting layer

    NASA Astrophysics Data System (ADS)

    Chen, Chong; Zhai, Yong; Li, Fumin; Tan, Furui; Yue, Gentian; Zhang, Weifeng; Wang, Mingtai

    2017-02-01

    The CH3NH3PbI3:CdS composite films are prepared by a newly developed precursor blending solution method, which are further used to fabricate CH3NH3PbI3:CdS perovskite solar cells. Our experimental results demonstrate that the introduced CdS effectively improves the light absorption property of the ITO/CuInS2/Al2O3/CH3NH3PbI3:CdS film stack and decreases the charge recombination in the prepared solar cells due to the formation of CH3NH3PbI3/CdS bulk heterojunction. Furthermore, the formed CdS/CuInS2 heterojunction also contributes to the enhanced efficiency. As a consequence, the CH3NH3PbI3/CdS bulk heterojunction perovskite solar cells exhibit a maximum power conversion efficiency of (16.5 ± 0.2)%, which is 1.35 times the best efficiency of 12.2% of previously reported CdS/CH3NH3PbI3 bilayer solar cell. In addition, this efficiency is a 59% improvement compared with the efficiency of (10.4 ± 0.2)% for the ITO/CuInS2/Al2O3/CH3NH3PbI3/PC60BM/Ag cell without CdS.

  13. The type Ia supernova SNLS-03D3bb from a super-Chandrasekhar-mass white dwarf star.

    PubMed

    Howell, D Andrew; Sullivan, Mark; Nugent, Peter E; Ellis, Richard S; Conley, Alexander J; Le Borgne, Damien; Carlberg, Raymond G; Guy, Julien; Balam, David; Basa, Stephane; Fouchez, Dominique; Hook, Isobel M; Hsiao, Eric Y; Neill, James D; Pain, Reynald; Perrett, Kathryn M; Pritchet, Christopher J

    2006-09-21

    The accelerating expansion of the Universe, and the need for dark energy, were inferred from observations of type Ia supernovae. There is a consensus that type Ia supernovae are thermonuclear explosions that destroy carbon-oxygen white dwarf stars that have accreted matter from a companion star, although the nature of this companion remains uncertain. These supernovae are thought to be reliable distance indicators because they have a standard amount of fuel and a uniform trigger: they are predicted to explode when the mass of the white dwarf nears the Chandrasekhar mass of 1.4 solar masses (M(o)). Here we show that the high-redshift supernova SNLS-03D3bb has an exceptionally high luminosity and low kinetic energy that both imply a super-Chandrasekhar-mass progenitor. Super-Chandrasekhar-mass supernovae should occur preferentially in a young stellar population, so this may provide an explanation for the observed trend that overluminous type Ia supernovae occur only in 'young' environments. As this supernova does not obey the relations that al