Science.gov

Sample records for orbital giant resonances

  1. The Pan-Pacific Planet Search. IV. Two Super-Jupiters in a 3:5 Resonance Orbiting the Giant Star HD 33844

    NASA Astrophysics Data System (ADS)

    Wittenmyer, Robert A.; Johnson, John Asher; Butler, R. P.; Horner, Jonathan; Wang, Liang; Robertson, Paul; Jones, M. I.; Jenkins, J. S.; Brahm, R.; Tinney, C. G.; Mengel, M. W.; Clark, J.

    2016-02-01

    We report the discovery of two giant planets orbiting the K giant HD 33844 based on radial velocity data from three independent campaigns. The planets move on nearly circular orbits with semimajor axes {a}b\\=1.60+/- 0.02 AU and {a}c=2.24+/- 0.05 AU, and have minimum masses (m sin i) of {M}b=1.96+/- 0.12 {M}{{Jup}} and {M}c=1.76+/- 0.18 {M}{{Jup}}. Detailed N-body dynamical simulations show that the two planets have remained on stable orbits for more than 106 years for low eccentricities and are most likely trapped in a mutual 3:5 mean motion resonance.

  2. Apical Orbital Aspergillosis Complicating Giant Cell Arteritis.

    PubMed

    Zhou, Yang; Morgan, Michael L; Almarzouqi, Sumayya J; Chevez-Barrios, Patricia; Lee, Andrew G

    2016-06-01

    A 75-year-old woman with new onset headaches and left vision loss, temporal scalp tenderness, and jaw claudication was found to have biopsy-proven giant cell arteritis (GCA). Despite treatment and improvement with prednisone, she later developed left orbital apex syndrome, and an orbital biopsy revealed aspergillosis. After antifungal treatment, extraocular motility improved although vision in the left eye remained no light perception. Clinicians should be aware that fungal orbital apex disease may mimic or complicate steroid-treated GCA. PMID:26835662

  3. 4f wavefunction collapse and giant resonances in molecules

    NASA Astrophysics Data System (ADS)

    Robin, M. B.

    1985-08-01

    The effective potential for an f orbital in an atom reflects both the attractive Coulomb and repulsive centrifugal forces, resulting in a double-well potential. Transitions from nd orbitals to f¯ orbitals bound in the inner well of the effective potential are unique in their frequency, intensity and response to external perturbations, and are known as "giant resonances". In molecules, the role of the repulsive centrifugal force is played instead by orthogonality to bonding valence orbitals, in which case the inner-well wavefunctions then become antibonding valence MOs. In general, the expected molecular giant resonances resulting from transitions between d-like MOs and antibonding valence MOs of f symmetry are not seen because of strong valence/Rydberg mixing. However, in certain molecules having high symmetries and the proper electronic configurations, this upper-state mixing is symmetry forbidden, and so molecular giant resonances can appear. These d → f¯ molecular giant resonances are identified for the first time in the vacuum-ultraviolet spectra of cyclopropane, cyclohexane, neopentane and uranium hexafluoride.

  4. Two Giant Planets Orbiting the K Giant Star η Cet

    NASA Astrophysics Data System (ADS)

    Trifonov, T.; Reffert, S.; Tan, X.; Lee, M. H.; Quirrenbach, A.

    2014-01-01

    We present evidence of a new planetary system around the K giant η Cet (HIP 5364, HD 6805, HR 334), based on 124 high-precision optical and infrared radial velocity data, taken at Lick Observatory (Hamilton) and at VLT (CRIRES). The best dynamical fit to the data is consistent with two massive planets (m 1sini~2.6M Jup , m 2sini~3.3MJup ) and with periods of P 1~407 days, P 2~740 days. To test the η Cet system's stability we perform ~ 10,000 dynamical investigations with maximum time spans of 108 years. We find that in case of moderate eccentricities, the planets can be effectively trapped in an anti-aligned stable 2:1 mean motion resonance (MMR), very close to the separatrix. A larger non-resonant stable region exists in low-eccentricity parameter space, although less probable than the 2:1 MMR region.

  5. Hierarchical spin-orbital polarization of a giant Rashba system

    PubMed Central

    Bawden, Lewis; Riley, Jonathan M.; Kim, Choong H.; Sankar, Raman; Monkman, Eric J.; Shai, Daniel E.; Wei, Haofei I.; Lochocki, Edward B.; Wells, Justin W.; Meevasana, Worawat; Kim, Timur K.; Hoesch, Moritz; Ohtsubo, Yoshiyuki; Le Fèvre, Patrick; Fennie, Craig J.; Shen, Kyle M.; Chou, Fangcheng; King, Phil D. C.

    2015-01-01

    The Rashba effect is one of the most striking manifestations of spin-orbit coupling in solids and provides a cornerstone for the burgeoning field of semiconductor spintronics. It is typically assumed to manifest as a momentum-dependent splitting of a single initially spin-degenerate band into two branches with opposite spin polarization. Combining polarization-dependent and resonant angle-resolved photoemission measurements with density functional theory calculations, we show that the two “spin-split” branches of the model giant Rashba system BiTeI additionally develop disparate orbital textures, each of which is coupled to a distinct spin configuration. This necessitates a reinterpretation of spin splitting in Rashba-like systems and opens new possibilities for controlling spin polarization through the orbital sector. PMID:26601268

  6. Orbital resonances around black holes.

    PubMed

    Brink, Jeandrew; Geyer, Marisa; Hinderer, Tanja

    2015-02-27

    We compute the length and time scales associated with resonant orbits around Kerr black holes for all orbital and spin parameters. Resonance-induced effects are potentially observable when the Event Horizon Telescope resolves the inner structure of Sgr A*, when space-based gravitational wave detectors record phase shifts in the waveform during the resonant passage of a compact object spiraling into the black hole, or in the frequencies of quasiperiodic oscillations for accreting black holes. The onset of geodesic chaos for non-Kerr spacetimes should occur at the resonance locations quantified here. PMID:25768747

  7. Origin of the orbital architecture of the giant planets of the Solar System.

    PubMed

    Tsiganis, K; Gomes, R; Morbidelli, A; Levison, H F

    2005-05-26

    Planetary formation theories suggest that the giant planets formed on circular and coplanar orbits. The eccentricities of Jupiter, Saturn and Uranus, however, reach values of 6 per cent, 9 per cent and 8 per cent, respectively. In addition, the inclinations of the orbital planes of Saturn, Uranus and Neptune take maximum values of approximately 2 degrees with respect to the mean orbital plane of Jupiter. Existing models for the excitation of the eccentricity of extrasolar giant planets have not been successfully applied to the Solar System. Here we show that a planetary system with initial quasi-circular, coplanar orbits would have evolved to the current orbital configuration, provided that Jupiter and Saturn crossed their 1:2 orbital resonance. We show that this resonance crossing could have occurred as the giant planets migrated owing to their interaction with a disk of planetesimals. Our model reproduces all the important characteristics of the giant planets' orbits, namely their final semimajor axes, eccentricities and mutual inclinations. PMID:15917800

  8. Dynamical Coupling of Pygmy and Giant Resonances

    NASA Astrophysics Data System (ADS)

    Bertulani, Carlos; Brady, Nathan; Aumann, Thomas; Thomas, James

    2016-03-01

    One of the effects overseen in studies of excitation of pygmy resonances is the fact that both pygmy and giant resonances are strongly coupled. This coupling leads to dynamical effects such as the modification of transition probabilities and and cross sections. We make an assessment of such effects by means of the relativistic coupled channels equations developed by our group. Supported by the U.S. NSF Grant No. 1415656 and the U.S. DOE Grant No. DE-FG02-08ER41533.

  9. The survival of gas giant planets on wide orbits

    NASA Astrophysics Data System (ADS)

    Stamatellos, Dimitris

    2015-12-01

    It is not known whether gas giant planets on wide orbits form the same way as Jupiter or by fragmentation of gravitationally unstable discs. It has been suggested that giant planets that form on wide orbits in gravitationally unstable discs quickly migrate towards the central star. We simulate the migration of such planets including the effects of gas accretion onto the planet and radiative feedback from the planet, both of which have been ignored in previous studies. We show that a giant planet, which has formed in the outer regions of a protostellar disc, initially migrates towards the central star while accreting gas from the disc. However, the planet eventually opens up a gap in the disc and the migration is essentially halted. At the same time, accretion-powered radiative feedback from the planet, significantly limits its mass growth, keeping it within the planetary mass regime (i.e. below the deuterium burning limit). Giant planets are therefore able to survive as planets (not higher-mass objects, i.e. brown dwarfs) on wide orbits, shaping the environment in which terrestrial planets that may harbour life form.

  10. Orbit of a Giant and a Dwarf

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2015-11-01

    The binary system Procyon, located a mere 11 light-years away, consists of a bright, subgiant star and a faint white dwarf presenting a distinct challenge for astronomers to observe. But careful analysis of two decades of precise measurements with the Hubble Space Telescope has now finally revealed some of its secrets.Challenging ObservationsPerturbations were detected as early as 1844 in the orbit of Procyon, originally thought to be a single star. Astronomers of the time suspected that this wobbling was due to the pull of a companion orbiting Procyon, but it wasnt until five decades later that the companion was first detected visually.Why? Because the subgiant Procyon A is the 8th brightest star in the sky. Its companion, on the other hand, is a white dwarf thats fainter (in visual wavelengths) by a factor of nearly 16,000! And the two stars are separated by an angular distance of less than 5.Due to the difficulty observing the system, the measurements of its motion and resulting estimates of the masses of the two stars have been a subject of debate for the better part of the last century.Led by Howard Bond (Pennsylvania State University and the Space Telescope Science Institute), a team of astronomers has now analyzed two decades of Hubble observations of the system, combined with historical, ground-based observations dating back to the 19th century. Bond and collaborators used these data to precisely measure the orbital elements of Procyon and obtain dynamical masses of the two stars.Surprising MixingRelative orbit of Procyon B around Procyon A. The red curve is the authors fit to the orbit, and the open blue circles are positions predicted by the orbital elements found. The black dots are the HST observations of Procyon B. The open green and turquoise circles are the (significantly less precise!) historical, ground-based observations. [Bond et al. 2015]The team reports that this system orbits once every 40.8 years. They find masses for the two stars of 1

  11. The Orbital Architecture of 55 Cnc: An Orbital Resonance, Jupiter Analog, and Transiting Super-Earth

    NASA Astrophysics Data System (ADS)

    Nelson, Benjamin E.; Payne, M.; Ford, E.; Wright, J.

    2011-09-01

    55 Cnc is the only naked eye star with a known transiting planet (Winn et al. 2011) and one of a few systems with five known planets characterized via Doppler methods. The planets span a wide range of masses and orbital periods. We investigate the orbital architecture, focusing on two of the giant planets near 3:1 mean-motion resonance and the potential impact on the dynamical effects on the other planets. To quantify the uncertainty in the orbital parameters of the 55 Cnc system requires exploring a high-dimensional ( 35) parameter space and using self-consistent N-body integrations, both of which are computationally demanding. To surmount these challenges, we apply a differential evolution Markov chain Monte Carlo algorithm to characterize the orbital properties and masses. We present these results and discuss the implications on the dynamical evolution of the 55 Cnc system.

  12. Stability of Minor-Body Orbits in Systems with Two Giant Planets

    NASA Astrophysics Data System (ADS)

    Lepage, Ian; Duncan, Martin J.

    2004-03-01

    We have performed a large ensemble of long-term numerical integrations to study the stability of the orbits of minor bodies in systems containing a solar-mass star and two giant planets. Given the large parameter space involved, we have focused on systems in which the inner planet has the mass of Jupiter (MJ) and the outer planet has a mass equal to either MJ or 1/3 MJ, and where we use an initially dynamically cold (e=0) minor-body population. We investigated the effects of the planetary semimajor-axis ratio, eccentricity, and inclination on the stability of orbits distributed throughout the system. We show that the behavior of the particles varies from region to region as the result of a complex interplay of the two major types of resonances: ``mean motion'' resonances associated with commensurabilities of orbital frequencies, and ``secular'' resonances associated with commensurabilities of orbital precession frequencies. In the region inward of the inner planet, mean motion resonances produce instabilities and secular resonances induce high eccentricities in the particles. Between the planets, the mean motion resonances are dominant and generally induce instability. Beyond the outer planet, secular and mean motion resonances overlap and produce wide-scale instability. In this last region, many stable particles are associated with mean motion resonances in various kinds of protective mechanisms. We also show that increased planetary eccentricity generally results in increased instability and that high initial inclination of both planet and test particles greatly changes the final structure of the system. Overall, our results show trends that make it possible to predict the general features of the minor-body distribution for a given set of orbital elements of the planets. We demonstrate this with two examples drawn from the set of observed extrasolar planetary systems.

  13. THE FORMATION MECHANISM OF GAS GIANTS ON WIDE ORBITS

    SciTech Connect

    Dodson-Robinson, Sarah E.; Veras, Dimitri; Ford, Eric B.; Beichman, C. A.

    2009-12-10

    The recent discoveries of massive planets on ultra-wide orbits of HR 8799 and Fomalhaut present a new challenge for planet formation theorists. Our goal is to figure out which of three giant planet formation mechanisms-core accretion (with or without migration), scattering from the inner disk, or gravitational instability-could be responsible for Fomalhaut b, HR 8799 b, c and d, and similar planets discovered in the future. This paper presents the results of numerical experiments comparing the long-period planet formation efficiency of each possible mechanism in model A star, G star, and M star disks. First, a simple core accretion simulation shows that planet cores forming beyond 35 AU cannot reach critical mass, even under the most favorable conditions one can construct. Second, a set of N-body simulations demonstrates that planet-planet scattering does not create stable, wide-orbit systems such as HR 8799. Finally, a linear stability analysis verifies previous work showing that global spiral instabilities naturally arise in high-mass disks. We conclude that massive gas giants on stable orbits with semimajor axes a approx> 35 AU form by gravitational instability in the disk. We recommend that observers examine the planet detection rate as a function of stellar age, controlling for the planets' dimming with time. Any age trend would indicate that planets on wide orbits are transient relics of scattering from the inner disk. If planet detection rate is found to be independent of stellar age, it would confirm our prediction that gravitational instability is the dominant mode of producing detectable planets on wide orbits. We also predict that the occurrence ratio of long-period to short-period gas giants should be highest for M dwarfs due to the inefficiency of core accretion and the expected small fragment mass (approx10 M {sub Jup}) in their disks.

  14. Managing resonant trapped orbits in our Galaxy

    NASA Astrophysics Data System (ADS)

    Binney, James

    2016-08-01

    Galaxy modelling is greatly simplified by assuming the existence of a global system of angle-action coordinates. Unfortunately, global angle-action coordinates do not exist because some orbits become trapped by resonances, especially where the radial and vertical frequencies coincide. We show that in a realistic Galactic potential such trapping occurs only on thick-disc and halo orbits (speed relative to the guiding centre ≳ 80 km s-1). We explain how the Torus Mapper code (TM) behaves in regions of phase space in which orbits are resonantly trapped, and we extend TM so trapped orbits can be manipulated as easily as untrapped ones. The impact that the resonance has on the structure of velocity space depends on the weights assigned to trapped orbits. The impact is everywhere small if each trapped orbit is assigned the phase space density equal to the time average along the orbit of the DF for untrapped orbits. The impact could be significant with a different assignment of weights to trapped orbits.

  15. Damping of giant resonances in hot nuclei

    SciTech Connect

    Smerzi, A.; Bonasera, A.; DiToro, M. )

    1991-10-01

    The effect of one- and two-body dissipation on the damping of giant dipole resonances (GDR's) is studied in a semiclassical approach solving a Vlasov equation with a collision relaxation time. The latter is microscopically evaluated from the equilibration of a distorted momentum distribution in a kinetic approach. Temperature effects are introduced in the initial distribution function and in Pauli blocking rearrangement in the path to equilibration. Particle emission is also computed in the same microscopic picture. Without free parameters a good agreement with data is obtained for GDR's on the ground state. For collective vibration built on excited states we get a dramatic increase of the widths due to the enhancement of nucleon-nucleon ({ital NN}) collisions. The saturation observed in some experiments is explained as due to the competition of particle evaporation which cools down the system. The transition to first-sound modes is ruled out for the persistence of long-nucleon mean free paths at relatively high temperatures.

  16. Giant dipole resonance in hot rotating nuclei

    NASA Astrophysics Data System (ADS)

    Chakrabarty, D. R.; Dinh Dang, N.; Datar, V. M.

    2016-05-01

    Over the last several decades, extensive experimental and theoretical work has been done on the giant dipole resonance (GDR) in excited nuclei covering a wide range of temperature ( T), angular momentum ( J) and nuclear mass. A reasonable stability of the GDR centroid energy and an increase of the GDR width with T (in the range ˜ 1 - 3 MeV) and J are the two well-established results. Some experiments have indicated the saturation of the GDR width at high T . The gradual disappearance of the GDR vibration at much higher T has been observed. Experiments on the Jacobi transition and the GDR built on superdeformed shapes at high rotational frequencies have been reported in a few cases. Theoretical calculations on the damping of the collective dipole vibration, characterised by the GDR width, have been carried out within various models such as the thermal shape fluctuation model and the phonon damping model. These models offer different interpretations of the variation of the GDR width with T and J and have met with varying degrees of success in explaining the experimental data. In this review, the present experimental and theoretical status in this field will be discussed along with the future outlook. The interesting phenomenon of the pre-equilibrium GDR excitation in nuclear reactions will be briefly addressed.

  17. DISSIPATIVE DIVERGENCE OF RESONANT ORBITS

    SciTech Connect

    Batygin, Konstantin; Morbidelli, Alessandro

    2013-01-01

    A considerable fraction of multi-planet systems discovered by the observational surveys of extrasolar planets reside in mild proximity to first-order mean-motion resonances. However, the relative remoteness of such systems from nominal resonant period ratios (e.g., 2:1, 3:2, and 4:3) has been interpreted as evidence for lack of resonant interactions. Here, we show that a slow divergence away from exact commensurability is a natural outcome of dissipative evolution and demonstrate that libration of critical angles can be maintained tens of percent away from nominal resonance. We construct an analytical theory for the long-term dynamical evolution of dissipated resonant planetary pairs and confirm our calculations numerically. Collectively, our results suggest that a significant fraction of the near-commensurate extrasolar planets are in fact resonant and have undergone significant dissipative evolution.

  18. FORMATION AND SURVIVABILITY OF GIANT PLANETS ON WIDE ORBITS

    SciTech Connect

    Vorobyov, Eduard I.; Basu, Shantanu E-mail: basu@astro.uwo.c

    2010-05-01

    Motivated by the recent discovery of massive planets on wide orbits, we present a mechanism for the formation of such planets via disk fragmentation in the embedded phase of star formation. In this phase, the forming disk intensively accretes matter from the natal cloud core and undergoes several fragmentation episodes. However, most fragments are either destroyed or driven into the innermost regions (and probably onto the star) due to angular momentum exchange with spiral arms, leading to multiple FU-Ori-like bursts and disk expansion. Fragments that are sufficiently massive and form in the late embedded phase (when the disk conditions are less extreme) may open a gap and evolve into giant planets on typical orbits of several tens to several hundreds of AU. For this mechanism to work, the natal cloud core must have sufficient mass and angular momentum to trigger the burst mode and also form extended disks of the order of several hundreds of AU. When mass loading from the natal cloud core diminishes and the main fragmentation phase ends, such extended disks undergo a transient episode of contraction and density increase, during which they may give birth to a last and survivable set of giant planets on wide and relatively stable orbits.

  19. Superconducting quantum spin Hall systems with giant orbital g factors

    NASA Astrophysics Data System (ADS)

    Reinthaler, R. W.; Tkachov, G.; Hankiewicz, E. M.

    2015-10-01

    Topological aspects of superconductivity in quantum spin Hall systems (QSHSs) such as thin layers of three-dimensional topological insulators (TIs) or two-dimensional TIs are the focus of current research. Here, we describe a superconducting quantum spin Hall effect (quantum spin Hall system in proximity to an s -wave superconductor and in orbital in-plane magnetic fields), which is protected against elastic backscattering by combined time-reversal and particle-hole symmetry. This effect is characterized by spin-polarized edge states, which can be manipulated in weak magnetic fields due to a giant effective orbital g factor, allowing the generation of spin currents. The phenomenon provides a solution to the outstanding challenge of detecting the spin polarization of the edge states. Here we propose the detection of the edge polarization in a three-terminal junction using unusual transport properties of the superconducting quantum Hall effect: a nonmonotonic excess current and a zero-bias conductance peak splitting.

  20. Deformation effects on isoscalar giant resonances in 24Mg

    NASA Astrophysics Data System (ADS)

    Gupta, Y. K.; Garg, U.; Hoffman, J.; Matta, J.; Rao, P. V. Madhusudhana; Patel, D.; Peach, T.; Yoshida, K.; Itoh, M.; Fujiwara, M.; Hara, K.; Hashimoto, H.; Nakanishi, K.; Yosoi, M.; Sakaguchi, H.; Terashima, S.; Kishi, S.; Murakami, T.; Uchida, M.; Yasuda, Y.; Akimune, H.; Kawabata, T.; Harakeh, M. N.

    2016-04-01

    Strength distributions for isoscalar giant resonances with multipolarity L ≤2 have been determined in 24Mg from "instrumental background-free" inelastic scattering of 386-MeV α particles at extreme forward angles, including 0∘. The isoscalar E 0 , E 1 , and E 2 strengths are observed to be 57 ±7 % , 111 .1-7.2+10.9% , and 148.6 ±7.3 % , respectively, of their energy-weighted sum rules in the excitation energy range of 6 to 35 MeV. The isoscalar giant monopole (ISGMR) and quadrupole (ISGQR) resonances exhibit a prominent K splitting which is consistent with microscopic theory for a prolate-deformed ground state of 24Mg. For the ISGQR it is due to splitting of the three K components, whereas for the ISGMR it is due to its coupling to the K =0 component of the ISGQR. Deformation effects on the isoscalar giant dipole resonance are less pronounced, however.

  1. Convert Acoustic Resonances to Orbital Angular Momentum

    NASA Astrophysics Data System (ADS)

    Jiang, Xue; Li, Yong; Liang, Bin; Cheng, Jian-chun; Zhang, Likun

    2016-07-01

    We use acoustic resonances in a planar layer of half-wavelength thickness to twist wave vectors of an in-coming plane wave into a spiral phase dislocation of an outgoing vortex beam with orbital angular momentum (OAM). The mechanism is numerically and experimentally demonstrated by producing an airborne Bessel-like vortex beam. Our acoustic resonance-based OAM production differs from existing means for OAM production by enormous phased spiral sources or by elaborate spiral profiles. Our study can advance the capability of generating phase dislocated wave fields for further applications of acoustic OAM.

  2. Convert Acoustic Resonances to Orbital Angular Momentum.

    PubMed

    Jiang, Xue; Li, Yong; Liang, Bin; Cheng, Jian-Chun; Zhang, Likun

    2016-07-15

    We use acoustic resonances in a planar layer of half-wavelength thickness to twist wave vectors of an in-coming plane wave into a spiral phase dislocation of an outgoing vortex beam with orbital angular momentum (OAM). The mechanism is numerically and experimentally demonstrated by producing an airborne Bessel-like vortex beam. Our acoustic resonance-based OAM production differs from existing means for OAM production by enormous phased spiral sources or by elaborate spiral profiles. Our study can advance the capability of generating phase dislocated wave fields for further applications of acoustic OAM. PMID:27472113

  3. Erratum: Resonant Tides in Close Orbiting Planets

    NASA Astrophysics Data System (ADS)

    Lubow, S. H.; Tout, C. A.; Livio, M.

    1999-06-01

    In the paper ``Resonant Tides in Close Orbiting Planets'' by S. H. Lubow, C. A. Tout, and M. Livio (ApJ, 484, 866 [1997]), there is a misprint in the abstract. The abstract states that ``the torque is exerted in a region where H/rp>>1....'' Instead, it should state that ``the torque is exerted in a region where H/rp<<1....''

  4. THE PROPOSED GIANT PLANET ORBITING VB 10 DOES NOT EXIST

    SciTech Connect

    Bean, Jacob L.; Seifahrt, Andreas; Reiners, Ansgar; Dreizler, Stefan; Hartman, Henrik; Nilsson, Hampus; Henry, Todd J.; Wiedemann, Guenter

    2010-03-01

    We present high-precision relative radial velocities of the very low mass star VB 10 that were obtained over a time span of 0.61 years as part of an ongoing search for planets around stars at the end of the main sequence. The radial velocities were measured from high-resolution near-infrared spectra obtained using the CRIRES instrument on the Very Large Telescope with an ammonia gas cell. The typical internal precision of the measurements is 10 m s{sup -1}. These data do not exhibit significant variability and are essentially constant at a level consistent with the measurement uncertainties. Therefore, we do not detect the radial velocity variations of VB 10 expected due to the presence of an orbiting giant planet similar to that recently proposed by Pravdo and Shaklan based on apparent astrometric perturbations. In addition, we do not confirm the {approx}1 km s{sup -1} radial velocity variability of the star tentatively detected by Zapatero Osorio and colleagues with lower precision measurements. Our measurements rule out planets with M {sub p} > 3 M {sub Jup} and the orbital period and inclination suggested by Pravdo and Shaklan at better than 5{sigma} confidence. We conclude that the planet detection claimed by Pravdo and Shaklan is spurious on the basis of this result. Although the outcome of this work is a non-detection, it illustrates the potential of using ammonia cell radial velocities to detect planets around very low mass stars.

  5. Collisional width of giant resonances and interplay with Landau damping

    SciTech Connect

    Bonasera, A.; Burgio, G. F.; Di Toro, M.; Wolter, H. H.

    1989-06-01

    We present a semiclassical method to calculate the widths of giant resonances. We solve a mean-field kinetic equation (Vlasov equation) with collision terms treated within the relaxation time approximation to construct a damped strength distribution for collective motions. The relaxation time is evaluated from the time evolution of distortions in the nucleon momentum distribution using a test-particle approach. The importance of an energy dependent nucleon-nucleon cross section is stressed. Results are shown for isoscalar giant quadrupole and octupole motions. A quite important interplay between self-consistent (Landau) and collisional damping is revealed.

  6. Spin-Orbit Activated Confinement Resonances

    NASA Astrophysics Data System (ADS)

    Keating, David; Manson, Steven; Deshmukh, Pranawa

    2016-05-01

    At high enough Z relativistic effects become important contributors to even the qualitative nature of atomic properties. This is likely to be true for confined atoms as well. One relativistic effect of interest is the spin-orbit activated interchannel coupling of a pair of spin-orbit doublet channels. This interaction is possible owing to the spin-orbit interaction breaking the degenerancy among the electrons of a subshell allowing, for example, the 5p3/2 and 5p1/2 subshells of mercury (Z = 80) and the 6p3/2 and 6p1/2 of radon (Z = 86), to interact. To explore the effect confinement has on spin-orbit activated interchannel coupling, a theoretical study of the 5p subshell of mercury and the 6p subshell of radon both confined in a C60 cage has been performed using the relativistic-random-phase approximation (RRPA) methodology. The effects of the C60 potential modeled by a static spherical well which is reasonable in the energy region well above the C60 plasmons. It is found in the photoionization cross sections of the 5p3/2 of confined mercury and the 6p3/2 of confined radon an extra confinement resonance due to spin-orbit activated interchannel coupling with the respective np1/2 photoionization channels.

  7. Extreme orbital evolution from hierarchical secular coupling of two giant planets

    SciTech Connect

    Teyssandier, Jean; Naoz, Smadar; Lizarraga, Ian; Rasio, Frederic A.

    2013-12-20

    Observations of exoplanets over the last two decades have revealed a new class of Jupiter-size planets with orbital periods of a few days, the so-called 'hot Jupiters'. Recent measurements using the Rossiter-McLaughlin effect have shown that many (∼50%) of these planets are misaligned; furthermore, some (∼15%) are even retrograde with respect to the stellar spin axis. Motivated by these observations, we explore the possibility of forming retrograde orbits in hierarchical triple configurations consisting of a star-planet inner pair with another giant planet, or brown dwarf, in a much wider orbit. Recently, it was shown that in such a system, the inner planet's orbit can flip back and forth from prograde to retrograde and can also reach extremely high eccentricities. Here we map a significant part of the parameter space of dynamical outcomes for these systems. We derive strong constraints on the orbital configurations for the outer perturber (the tertiary) that could lead to the formation of hot Jupiters with misaligned or retrograde orbits. We focus only on the secular evolution, neglecting other dynamical effects such as mean-motion resonances, as well as all dissipative forces. For example, with an inner Jupiter-like planet initially on a nearly circular orbit at 5 AU, we show that a misaligned hot Jupiter is likely to be formed in the presence of a more massive planetary companion (>2 M{sub J} ) within ∼140 AU of the inner system, with mutual inclination >50° and eccentricity above ∼0.25. This is in striking contrast to the test particle approximation, where an almost perpendicular configuration can still cause large-eccentricity excitations, but flips of an inner Jupiter-like planet are much less likely to occur. The constraints we derive can be used to guide future observations and, in particular, searches for more distant companions in systems containing a hot Jupiter.

  8. Mercury's resonant rotation from secular orbital elements

    NASA Astrophysics Data System (ADS)

    Stark, Alexander; Oberst, Jürgen; Hussmann, Hauke

    2015-11-01

    We used recently produced Solar System ephemerides, which incorporate 2 years of ranging observations to the MESSENGER spacecraft, to extract the secular orbital elements for Mercury and associated uncertainties. As Mercury is in a stable 3:2 spin-orbit resonance, these values constitute an important reference for the planet's measured rotational parameters, which in turn strongly bear on physical interpretation of Mercury's interior structure. In particular, we derive a mean orbital period of (87.96934962 ± 0.00000037) days and (assuming a perfect resonance) a spin rate of (6.138506839± 0.000000028)°/day. The difference between this rotation rate and the currently adopted rotation rate (Archinal et al. in Celest Mech Dyn Astron 109(2):101-135, 2011. doi:10.1007/s10569-010-9320-4), corresponds to a longitudinal displacement of approx. 67 m per year at the equator. Moreover, we present a basic approach for the calculation of the orientation of the instantaneous Laplace and Cassini planes of Mercury. The analysis allows us to assess the uncertainties in physical parameters of the planet, when derived from observations of Mercury's rotation.

  9. Orbitally-driven giant phonon anharmonicity in SnSe

    SciTech Connect

    Li, Chen W.; Hong, Jiawang; May, Andrew F.; Bansal, Dipanshu; Chi, Songxue; Hong, Tao; Ehlers, Georg; Delaire, Olivier A.

    2015-10-19

    We understand that elementary excitations and their couplings in condensed matter systems is critical to develop better energy-conversion devices. In thermoelectric materials, the heat-to-electricity conversion efficiency is directly improved by suppressing the propagation of phonon quasiparticles responsible for macroscopic thermal transport. The material with the current record for thermoelectric conversion efficiency, SnSe, achieves an ultra-low thermal conductivity, but the mechanism enabling this strong phonon scattering remains largely unknown. Using inelastic neutron scattering measurements and first-principles simulations, we mapped the four-dimensional phonon dispersion surfaces of SnSe, and revealed the origin of ionic-potential anharmonicity responsible for the unique properties of SnSe. We show that the giant phonon scattering arises from an unstable electronic structure, with orbital interactions leading to a ferroelectric-like lattice instability. Our results provide a microscopic picture connecting electronic structure and phonon anharmonicity in SnSe, and offers precious insights on how electron-phonon and phononphonon interactions may lead to the realization of ultra-low thermal conductivity.

  10. Orbitally-driven giant phonon anharmonicity in SnSe

    DOE PAGESBeta

    Li, Chen W.; Hong, Jiawang; May, Andrew F.; Bansal, Dipanshu; Chi, Songxue; Hong, Tao; Ehlers, Georg; Delaire, Olivier A.

    2015-10-19

    We understand that elementary excitations and their couplings in condensed matter systems is critical to develop better energy-conversion devices. In thermoelectric materials, the heat-to-electricity conversion efficiency is directly improved by suppressing the propagation of phonon quasiparticles responsible for macroscopic thermal transport. The material with the current record for thermoelectric conversion efficiency, SnSe, achieves an ultra-low thermal conductivity, but the mechanism enabling this strong phonon scattering remains largely unknown. Using inelastic neutron scattering measurements and first-principles simulations, we mapped the four-dimensional phonon dispersion surfaces of SnSe, and revealed the origin of ionic-potential anharmonicity responsible for the unique properties of SnSe. Wemore » show that the giant phonon scattering arises from an unstable electronic structure, with orbital interactions leading to a ferroelectric-like lattice instability. Our results provide a microscopic picture connecting electronic structure and phonon anharmonicity in SnSe, and offers precious insights on how electron-phonon and phononphonon interactions may lead to the realization of ultra-low thermal conductivity.« less

  11. Giant dipole resonances in the interacting boson model

    NASA Astrophysics Data System (ADS)

    Scholtz, F. G.; Hahne, F. J. W.

    1983-03-01

    Giant dipole resonances, represented by p bosons, are introduced into the interacting boson model. For nuclei with SU(3) symmetry the dipole is split by the interactions into two main parts, with any further fragmentation being generally small. The Raman scattering to side bands tends to be very small. This agrees with recent measurements on Er. Supported by the National Accelerator Centre, CSIR, Faure, South Africa.

  12. Bodily tides near spin-orbit resonances

    NASA Astrophysics Data System (ADS)

    Efroimsky, Michael

    2012-03-01

    Spin-orbit coupling can be described in two approaches. The first method, known as the "MacDonald torque", is often combined with a convenient assumption that the quality factor Q is frequency-independent. This makes the method inconsistent, because derivation of the expression for the MacDonald torque tacitly fixes the rheology of the mantle by making Q scale as the inverse tidal frequency. Spin-orbit coupling can be treated also in an approach called "the Darwin torque". While this theory is general enough to accommodate an arbitrary frequency-dependence of Q, this advantage has not yet been fully exploited in the literature, where Q is often assumed constant or is set to scale as inverse tidal frequency, the latter assertion making the Darwin torque equivalent to a corrected version of the MacDonald torque. However neither a constant nor an inverse-frequency Q reflect the properties of realistic mantles and crusts, because the actual frequency-dependence is more complex. Hence it is necessary to enrich the theory of spin-orbit interaction with the right frequency-dependence. We accomplish this programme for the Darwin-torque-based model near resonances. We derive the frequency-dependence of the tidal torque from the first principles of solid-state mechanics, i.e., from the expression for the mantle's compliance in the time domain. We also explain that the tidal torque includes not only the customary, secular part, but also an oscillating part. We demonstrate that the lmpq term of the Darwin-Kaula expansion for the tidal torque smoothly passes zero, when the secondary traverses the lmpq resonance (e.g., the principal tidal torque smoothly goes through nil as the secondary crosses the synchronous orbit). Thus, we prepare a foundation for modeling entrapment of a despinning primary into a resonance with its secondary. The roles of the primary and secondary may be played, e.g., by Mercury and the Sun, correspondingly, or by an icy moon and a Jovian planet. We also

  13. A giant planet orbiting the 'extreme horizontal branch' star V 391 Pegasi.

    PubMed

    Silvotti, R; Schuh, S; Janulis, R; Solheim, J-E; Bernabei, S; Østensen, R; Oswalt, T D; Bruni, I; Gualandi, R; Bonanno, A; Vauclair, G; Reed, M; Chen, C-W; Leibowitz, E; Paparo, M; Baran, A; Charpinet, S; Dolez, N; Kawaler, S; Kurtz, D; Moskalik, P; Riddle, R; Zola, S

    2007-09-13

    After the initial discoveries fifteen years ago, over 200 extrasolar planets have now been detected. Most of them orbit main-sequence stars similar to our Sun, although a few planets orbiting red giant stars have been recently found. When the hydrogen in their cores runs out, main-sequence stars undergo an expansion into red-giant stars. This expansion can modify the orbits of planets and can easily reach and engulf the inner planets. The same will happen to the planets of our Solar System in about five billion years and the fate of the Earth is matter of debate. Here we report the discovery of a planetary-mass body (Msini = 3.2M(Jupiter)) orbiting the star V 391 Pegasi at a distance of about 1.7 astronomical units (au), with a period of 3.2 years. This star is on the extreme horizontal branch of the Hertzsprung-Russell diagram, burning helium in its core and pulsating. The maximum radius of the red-giant precursor of V 391 Pegasi may have reached 0.7 au, while the orbital distance of the planet during the stellar main-sequence phase is estimated to be about 1 au. This detection of a planet orbiting a post-red-giant star demonstrates that planets with orbital distances of less than 2 au can survive the red-giant expansion of their parent stars. PMID:17851517

  14. Giant dipole resonance in hot and rotating nuclei

    NASA Astrophysics Data System (ADS)

    Banerjee, Sudhee R.

    2013-04-01

    The study of Giant Dipole Resonance (GDR) even after more than 60 years of its discovery, still remains an intriguing and a very relevant topic of research particularly in the case of hot and fast rotating nuclei. Many new facets of this giant collective mode of vibration are being brought to light recently owing to the new age powerful detection systems. Particularly for the nuclei with large asymmetries in its neutron and protons the study of its GDR decay modes opened up very interesting research prospects worldwide. Even with low energy light-ion and heavy-ion accelerated beams and employing the powerful large volume high energy photon spectrometer LAMBDA at VECC a number of very interesting experimental observations have been made recently which radically changes the present understanding of GDR vibrations in moderately hot nuclei in general. The availability of higher energy heavy-ion beams from the near ready superconducting cyclotron at VECC will open up many more interesting and challenging research prospects with the LAMBDA spectrometer. Exciting challenges and opportunities are also on offer for studying the properties and dynamics of hot exotic nuclei with stable and RI beams through high energy gamma decays from giant resonances. A few of the very interesting results obtained recently at VECC with the LAMBDA spectrometer, further research possibilities and several other powerful detector facilities will be discussed during the conference.

  15. Extrasolar Giant Planet in Earth-like Orbit

    NASA Astrophysics Data System (ADS)

    1999-07-01

    companion . iota Hor b has an orbital period of 320 days. From this period, the known mass of the central star (1.03 solar masses) and the amplitude of the velocity changes, a mass of at least 2.26 times that of planet Jupiter is deduced for the planet. It revolves around the host star in a somewhat elongated orbit (the eccentricity is 0.16). If it were located in our own solar system, this orbit would stretch from just outside the orbit of Venus (at 117 million km or 0.78 Astronomical Units from the Sun) to just outside the orbit of the Earth (the point farthest from the Sun, at 162 million km or 1.08 Astronomical Units) The new giant planet is thus moving in an orbit not unlike that of the Earth. In fact, of all the planets discovered so far, the orbit of iota Hor b is the most Earth-like. Also, with a spectral type of G0 V , its host star is quite similar to the Sun (G2 V). iota Hor b is, however, at least 720 times more massive than the Earth and it is probably more similar to planet Jupiter in our own solar system. While the radial velocity technique described above only determines a minimum value for the planet's mass, an analysis of the velocity with which the star turns around its own axis suggests that the true mass of iota Hor b is unlikely to be much higher. A difficult case Natural phenomena with periods near one solar year always present a particular challenge to astronomers. This is one of the reasons why it has been necessary to observe the iota Hor system for such a long time to be absolutely sure about the present result. First, special care must be taken to verify that the radial velocity variations found in the data are not an artefact of the Earth's movement around the Sun. In any case, the effect of this movement on the measurements must be accurately accounted for; it reaches about ± 30 km/sec over one year, i.e. much larger than the effect of the new planet. In the present case of iota Hor , this was thoroughly tested and any residual influence of

  16. Fourteen years of resonance of Vanguard orbits

    NASA Technical Reports Server (NTRS)

    Wagner, C. A.

    1975-01-01

    Tracking of Vanguard 3 and the Vanguard 2 rocket with Baker-Nunn cameras and the U.S. Navy's Space Surveillance (radio interferometer) system over a 14 year period revealed resonant fluctuations of up to 0.035 deg in inclination (peak to peak). Six geopotential terms (lumped coefficients) of 11th order and three of 22nd order were measured using orbit inclinations derived from this tracking record. The terms of 11th order are significantly smaller than Kaula's rule. (The lumped coefficients are sensitive to geopotential effects as high as 37th degree.) These observed terms are compatible with a recent 27-satellite geopotential solution whose formal coefficient errors are increased by a factor of 3.3.

  17. Excitation and photon decay of giant resonances excited by intermediate energy heavy ions

    SciTech Connect

    Bertrand, F.E.; Beene, J.R.

    1987-01-01

    Inelastic scattering of medium energy heavy ions provides very large cross sections and peak-to-continuum ratios for excitation of giant resonances. For energies above about 50 MeV/nucleon, giant resonances are excited primarily through Coulomb excitation, which is indifferent to isospin, thus providing a good probe for the study of isovector giant resonances. The extremely large cross sections available from heavy ion excitation permit the study of rare decay modes of the giant resonances. In particular, recent measurements have been made of the photon decay of giant resonances following excitation by 22 and 84 MeV/nucleon /sup 17/O projectiles. The singles results at 84 MeV/nucleon yield peak cross sections for the isoscalar giant quadrupole resonance and the isovector giant dipole resonance of approximately 0.8 and 3 barns/sr, respectively. Data on the ground state decay of the isoscalar giant quadrupole and isovector giant dipole resonances are presented and compared with calculations. Decays to low-lying excited states are also discussed. Preliminary results from an experiment to isolate the /sup 208/Pb isovector quadrupole resonance using its gamma decay are presented. 22 refs., 19 figs., 1 tab.

  18. Kinetic approach to the damping of giant quadrupole resonances

    SciTech Connect

    Bonasera, A.; Di Toro, M.; Gulminelli, F. Dipartimento di Fisica, Corso Italia 57, 95129 Catania Dipartimento di Fisica, Via Celoria 16, 20133 Milano Laboratorio Nazionale del Sud, Viale A. Doria, 95125 Catania )

    1990-09-01

    The effect of one- and two-body dissipation on the damping of giant quadrupole resonances is studied in a semiclassic approach solving a Vlasov equation with a collisional relaxation time. The latter is microscopically evaluated from the equilibration of a distorted momentum distribution in a kinetic approach. Important effects from energy and angle dependent nucleon-nucleon ({ital NN}) cross sections and from the time variation of Pauli blocking are stressed. Once these points are suitably treated, a good agreement with the experimental systematics is obtained from the use of a free {ital NN} cross section.

  19. Kozai's resonance in the orbital motions of CBERS satellites

    NASA Astrophysics Data System (ADS)

    Sampaio, Jarbas; Vilhena de Moraes, Rodolpho; Da Silva Fernandes, Sandro

    The objects orbiting the Earth are classified, basically, in Low Earth Orbit (LEO), Medium Earth Orbit (MEO) and Geosynchronous Orbit (GEO). Most of the objects are found in the LEO region because this region has a big quantity of space debris. Currently, the orbital motions of the cataloged objects can be analyzed using the 2-line element set of the NORAD (North American Defense). In this work, resonant orbital motions of the CBERS (China-Brazil Earth Resource Satellite) satellites are studied using the TLE files of the NORAD. Analyzing the motions of artificial satellites CBERS-1 and CBERS-2, one can observe resonant angles in the neighborhood of the exact 14:1 resonance. The orbital motions of the CBERS satellites can be corrected during your lifetime, because some disturbances, resonance effects or collision risk can affect your mission. These corrections can be seen by the abrupt change in the values of the semi-major axis. In this way, the study of the resonant angles using real data of the artificial satellites is limited to the period without corrections. However, the study involving space debris allows to use a long time and consequently a better analysis about the resonant period in a given region. The results and discussions show the complexity, in the orbital dynamics of these objects, caused by the resonance effects. Figures show the time behavior of the semimajor axis, eccentricity, resonant periods and resonant angles. Energy's curves are observed in the (omega, e) plane of the orbital motions of CBERS satellites indicating the presence of Kozai's resonance in their orbits. Where omega is the argument of pericentre and e is the eccentricity.

  20. Isoscalar Giant Dipole Resonance within Fermi Liquid Drop Model

    NASA Astrophysics Data System (ADS)

    Pochivalov, Oleksiy; Shlomo, Shalom

    2006-04-01

    Recent highly accurate experimental data on Isoscalar Giant Dipole (ISGDR) and Monopole (ISGMR) Resonances in nuclei renewed interest in correct microscopic description of collective excitations. Hartree-Fock based Random-Phase-Approximation (HF-RPA) is a successful method of describing collective excitations in nuclei. However, recent fully self-consistent HF-RPA calculations, which reproduce the centroid energies of the ISGMR, systematically overestimate by 1.5-2.5 MeV results for the ISGDR energy comparing with experimentally obtained data. Also, the HF-RPA model does not provide description of the widths of giant resonances. We consider these issues within the semi-classical generalization of the mean field theory, namely, Fermi-Liquid-Drop-Model (FLDM). In this presentation, we provide description of the FLDM formalism in its application to ISGDR and ISGMR calculations. We present results of FLDM calculations for centroid energy and widths of the ISGDR and ISGMR in the four nuclei, namely, 90Zr, 116Sn, 144Sm, and 208Pb and compare with available experimental data.

  1. Relaxation of giant resonances: Semimicroscopic description (Methods, Results, and Prospects)

    SciTech Connect

    Urin, M. H.

    2011-08-15

    An account of a semimicroscopic approach to globally describing dominant relaxation modes for giant resonances in spherical nuclei is given. This approach is based on the continuum version of the random-phase approximation and on a phenomenological description of the fragmentation effect. The fragmentation effect in question is taken into account in the 'pole' approximation in terms of the excitationenergy-dependent imaginary part of the single-particle effective optical potential directly in the equations of the approximation in question. In the practical implementation of the above approach, use is made of the Landau-Migdal interaction in the particle-hole channel and a phenomenological mean field of the nucleus being considered, these two being related by a partial-consistency condition. The results obtained within this approach by calculating integrated and differential features for a number of giant resonances over a broad range of excitation energies are used to perform a comparison with available experimental data and to predict the results of possible experiments. A particle-hole optical model that serves both as a substantiation for the existing version of the semimicroscopic approach and as a basic element for describing excitations of the particle-hole type at an arbitrary (albeit rather high) energy is formulated.

  2. TERRESTRIAL PLANET FORMATION DURING THE MIGRATION AND RESONANCE CROSSINGS OF THE GIANT PLANETS

    SciTech Connect

    Lykawka, Patryk Sofia; Ito, Takashi

    2013-08-10

    The newly formed giant planets may have migrated and crossed a number of mutual mean motion resonances (MMRs) when smaller objects (embryos) were accreting to form the terrestrial planets in the planetesimal disk. We investigated the effects of the planetesimal-driven migration of Jupiter and Saturn, and the influence of their mutual 1:2 MMR crossing on terrestrial planet formation for the first time, by performing N-body simulations. These simulations considered distinct timescales of MMR crossing and planet migration. In total, 68 high-resolution simulation runs using 2000 disk planetesimals were performed, which was a significant improvement on previously published results. Even when the effects of the 1:2 MMR crossing and planet migration were included in the system, Venus and Earth analogs (considering both orbits and masses) successfully formed in several runs. In addition, we found that the orbits of planetesimals beyond a {approx} 1.5-2 AU were dynamically depleted by the strengthened sweeping secular resonances associated with Jupiter's and Saturn's more eccentric orbits (relative to the present day) during planet migration. However, this depletion did not prevent the formation of massive Mars analogs (planets with more than 1.5 times Mars's mass). Although late MMR crossings (at t > 30 Myr) could remove such planets, Mars-like small mass planets survived on overly excited orbits (high e and/or i), or were completely lost in these systems. We conclude that the orbital migration and crossing of the mutual 1:2 MMR of Jupiter and Saturn are unlikely to provide suitable orbital conditions for the formation of solar system terrestrial planets. This suggests that to explain Mars's small mass and the absence of other planets between Mars and Jupiter, the outer asteroid belt must have suffered a severe depletion due to interactions with Jupiter/Saturn, or by an alternative mechanism (e.g., rogue super-Earths)

  3. The Weihai Observatory Search for Close-in Planets Orbiting Giant Stars

    NASA Astrophysics Data System (ADS)

    Wittenmyer, Robert A.; Gao, Dongyang; Hu, Shao Ming; Villaver, Eva; Endl, Michael; Wright, Duncan

    2015-10-01

    Planets are known to orbit giant stars, yet there is a shortage of planets orbiting within ~0.5 AU (P lsim 100 days). First-ascent giants have not expanded enough to engulf such planets, but tidal forces can bring planets to the surface of the star far beyond the stellar radius. So the question remains: Are tidal forces strong enough in these stars to engulf all the missing planets? We describe a high-cadence observational program to obtain precise radial velocities of bright giants from Weihai Observatory of Shandong University. We present data on the planet host Beta Gem (HD 62509), confirming our ability to derive accurate and precise velocities; our data achieve an rms of 7.3 m s-1 about the Keplerian orbit fit. This planet-search program currently receives ~100 nights per year, allowing us to aggressively pursue short-period planets to determine whether they are truly absent.

  4. GIANT PLANETS ORBITING METAL-RICH STARS SHOW SIGNATURES OF PLANET-PLANET INTERACTIONS

    SciTech Connect

    Dawson, Rebekah I.; Murray-Clay, Ruth A.

    2013-04-20

    Gas giants orbiting interior to the ice line are thought to have been displaced from their formation locations by processes that remain debated. Here we uncover several new metallicity trends, which together may indicate that two competing mechanisms deliver close-in giant planets: gentle disk migration, operating in environments with a range of metallicities, and violent planet-planet gravitational interactions, primarily triggered in metal-rich systems in which multiple giant planets can form. First, we show with 99.1% confidence that giant planets with semimajor axes between 0.1 and 1 AU orbiting metal-poor stars ([Fe/H] < 0) are confined to lower eccentricities than those orbiting metal-rich stars. Second, we show with 93.3% confidence that eccentric proto-hot Jupiters undergoing tidal circularization primarily orbit metal-rich stars. Finally, we show that only metal-rich stars host a pile-up of hot Jupiters, helping account for the lack of such a pile-up in the overall Kepler sample. Migration caused by stellar perturbers (e.g., stellar Kozai) is unlikely to account for the trends. These trends further motivate follow-up theoretical work addressing which hot Jupiter migration theories can also produce the observed population of eccentric giant planets between 0.1 and 1 AU.

  5. Tidal interactions of a Maclaurin spheroid - II. Resonant excitation of modes by a close, misaligned orbit

    NASA Astrophysics Data System (ADS)

    Braviner, Harry J.; Ogilvie, Gordon I.

    2015-02-01

    We model a tidally forced star or giant planet as a Maclaurin spheroid, decomposing the motion into the normal modes found by Bryan. We first describe the general prescription for this decomposition and the computation of the tidal power. Although this formalism is very general, forcing due to a companion on a misaligned, circular orbit is used to illustrate the theory. The tidal power is plotted for a variety of orbital radii, misalignment angles, and spheroid rotation rates. Our calculations are carried out including all modes of degree l ≤ 4, and the same degree of gravitational forcing. Remarkably, we find that for close orbits (a/R* ≈ 3) and rotational deformations that are typical of giant planets (e ≈ 0.4) the l = 4 component of the gravitational potential may significantly enhance the dissipation through resonance with surface gravity modes. There are also a large number of resonances with inertial modes, with the tidal power being locally enhanced by up to three orders of magnitude. For very close orbits (a/R* ≈ 3), the contribution to the power from the l = 4 modes is roughly the same magnitude as that due to the l = 3 modes.

  6. Resonant excitation of black holes by massive bosonic fields and giant ringings

    NASA Astrophysics Data System (ADS)

    Décanini, Yves; Folacci, Antoine; Ould El Hadj, Mohamed

    2014-04-01

    We consider the massive scalar field, the Proca field, and the Fierz-Pauli field in the Schwarzschild spacetime and we focus more particularly on their long-lived quasinormal modes. We show numerically that the associated excitation factors have a strong resonant behavior and we confirm this result analytically from semiclassical considerations based on the properties of the unstable circular geodesics on which a massive particle can orbit the black hole. The conspiracy of (i) the long-lived behavior of the quasinormal modes and (ii) the resonant behavior of their excitation factors induces intrinsic giant ringings, i.e., ringings of a huge amplitude. Such ringings, which are moreover slowly decaying, are directly constructed from the retarded Green function. If we describe the source of the black hole perturbation by an initial value problem with Gaussian initial data, i.e., if we consider the excitation of the black hole from an extrinsic point of view, we can show that these extraordinary ringings are still present. This suggests that physically realistic sources of perturbations should generate giant and slowly decaying ringings and that their existence could be used to constrain ultralight bosonic field theory interacting with black holes.

  7. Phase-space exploration in nuclear giant resonance decay

    SciTech Connect

    Drozdz, S.; Nishizaki, S.; Wambach, J.; Speth, J. Institute of Nuclear Physics, PL-31-342 Krakow Department of Physics, University of Illinois at Urbana, Illinois 61801 College of Humanities and Social Sciences, Iwate University, Ueda 3-18-34, Morioka 020 )

    1995-02-13

    The rate of phase-space exploration in the decay of isovector and isoscalar giant quadrupole resonances in [sup 40]Ca is analyzed. The study is based on the time dependence of the survival probability and of the spectrum of generalized entropies evaluated in the space of one-particle--one-hole (1p-1h) and 2p-2h states. Three different cases for the level distribution of 2p-2h background states, corresponding to (a) high degeneracy, (b) classically regular motion, and (c) classically chaotic motion, are studied. In the latter case the isovector excitation evolves almost statistically while the isoscalar excitation remains largely localized, even though it penetrates the whole available phase space.

  8. Driving Rabi oscillations at the giant dipole resonance in xenon

    NASA Astrophysics Data System (ADS)

    Pabst, Stefan; Wang, Daochen; Santra, Robin

    2015-11-01

    Free-electron lasers (FELs) produce short and very intense light pulses in the XUV and x-ray regimes. We investigate the possibility to drive Rabi oscillations in xenon with an intense FEL pulse by using the unusually large dipole strength of the giant dipole resonance (GDR). The GDR decays within less than 30 as due to its position, which is above the 4 d ionization threshold. We find that intensities around 1018W /cm2 are required to induce Rabi oscillations with a period comparable to the lifetime. The pulse duration should not exceed 100 as because xenon will be fully ionized within a few lifetimes. Rabi oscillations reveal themselves also in the photoelectron spectrum in the form of Autler-Townes splittings extending over several tens of electronvolts.

  9. Near strongly resonant periodic orbits in a Hamiltonian system

    PubMed Central

    Gelfreich, Vassili

    2002-01-01

    We study an analytic Hamiltonian system near a strongly resonant periodic orbit. We introduce a modulus of local analytic classification. We provide asymptotic formulae for the exponentially small splitting of separatrices for bifurcating hyperbolic periodic orbits. These formulae confirm a conjecture formulated by V. I. Arnold in the early 1970s. PMID:12391324

  10. Jupiter: Giant of the solar system. [its solar orbits

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Jupiter, its relationship to the other planets in the solar system, its twelve natural satellites, solar orbit and the appearance of Jupiter in the sky, and the sightings and motions of Jupiter in 1973 are discussed. Educational study projects for students are also included.

  11. AN INTERPRETATION OF THE ORBITAL PERIOD DIFFERENCE BETWEEN HOT JUPITERS AND GIANT PLANETS ON LONG-PERIOD ORBITS

    SciTech Connect

    Jin Liping

    2010-09-10

    It is believed that a hot Jupiter (giant planet with a short period less than 10 days) forms in the outer region of a protoplanetary disk, then migrates inward to an orbit with a short period around 3 days, and stops there by a final stopping mechanism. The prominent problem is why hot Jupiters migrate inward to short-period orbits, while other extrasolar giant planets and Jovian planets in our solar system exist on long-period orbits. Here we show that this difference in orbital periods is caused by two populations of protoplanetary disks. One population experiences gravitational instability during some periods of their lifetime (GI disks), while the other does not (No-GI disks). In GI disks, planets can quickly migrate inward to short-period orbits to become hot Jupiters. In No-GI disks, the migration is so slow that planets can exist on long-period orbits. Protoplanetary disks are classified into the two populations because of the differences in properties of molecular cloud cores, from which disks from. We specifically compare our theory with observations. Our theory is supported by observations of extrasolar planets. We analyze the current status of our solar system and find that our solar nebula belongs to the population with a low migration rate. This is consistent with the observation that Jupiter and Saturn are indeed on long-period orbits. Our results further suggest that, in the future observations, a hot Jupiter cannot be found around a star with mass below a critical mass (0.14-0.28 M {sub sun}).

  12. FORMATION OF GIANT PLANETS BY DISK INSTABILITY ON WIDE ORBITS AROUND PROTOSTARS WITH VARIED MASSES

    SciTech Connect

    Boss, Alan P.

    2011-04-10

    Doppler surveys have shown that more massive stars have significantly higher frequencies of giant planets inside {approx}3 AU than lower mass stars, consistent with giant planet formation by core accretion. Direct imaging searches have begun to discover significant numbers of giant planet candidates around stars with masses of {approx}1 M{sub sun} to {approx}2 M{sub sun} at orbital distances of {approx}20 AU to {approx}120 AU. Given the inability of core accretion to form giant planets at such large distances, gravitational instabilities of the gas disk leading to clump formation have been suggested as the more likely formation mechanism. Here, we present five new models of the evolution of disks with inner radii of 20 AU and outer radii of 60 AU, for central protostars with masses of 0.1, 0.5, 1.0, 1.5, and 2.0 M{sub sun}, in order to assess the likelihood of planet formation on wide orbits around stars with varied masses. The disk masses range from 0.028 M{sub sun} to 0.21 M{sub sun}, with initial Toomre Q stability values ranging from 1.1 in the inner disks to {approx}1.6 in the outer disks. These five models show that disk instability is capable of forming clumps on timescales of {approx}10{sup 3} yr that, if they survive for longer times, could form giant planets initially on orbits with semimajor axes of {approx}30 AU to {approx}70 AU and eccentricities of {approx}0 to {approx}0.35, with initial masses of {approx}1 M{sub Jup} to {approx}5 M{sub Jup}, around solar-type stars, with more protoplanets forming as the mass of the protostar (and protoplanetary disk) is increased. In particular, disk instability appears to be a likely formation mechanism for the HR 8799 gas giant planetary system.

  13. Orbital Feshbach Resonance in Alkali-Earth Atoms.

    PubMed

    Zhang, Ren; Cheng, Yanting; Zhai, Hui; Zhang, Peng

    2015-09-25

    For a mixture of alkali-earth atomic gas in the long-lived excited state ^{3}P_{0} and the ground state ^{1}S_{0}, in addition to nuclear spin, another "orbital" index is introduced to distinguish these two internal states. In this Letter we propose a mechanism to induce Feshbach resonance between two atoms with different orbital and nuclear spin quantum numbers. Two essential ingredients are the interorbital spin-exchange process and orbital dependence of the Landé g factors. Here the orbital degrees of freedom plays a similar role as the electron spin degree of freedom in magnetic Feshbach resonance in alkali-metal atoms. This resonance is particularly accessible for the ^{173}Yb system. The BCS-BEC crossover in this system requires two fermion pairing order parameters, and displays a significant difference compared to that in an alkali-metal system. PMID:26451561

  14. Orbital Feshbach Resonance in Alkali-Earth Atoms

    NASA Astrophysics Data System (ADS)

    Zhang, Ren; Cheng, Yanting; Zhai, Hui; Zhang, Peng

    2015-09-01

    For a mixture of alkali-earth atomic gas in the long-lived excited state 3P0 and the ground state 1S0, in addition to nuclear spin, another "orbital" index is introduced to distinguish these two internal states. In this Letter we propose a mechanism to induce Feshbach resonance between two atoms with different orbital and nuclear spin quantum numbers. Two essential ingredients are the interorbital spin-exchange process and orbital dependence of the Landé g factors. Here the orbital degrees of freedom plays a similar role as the electron spin degree of freedom in magnetic Feshbach resonance in alkali-metal atoms. This resonance is particularly accessible for the 173Yb system. The BCS-BEC crossover in this system requires two fermion pairing order parameters, and displays a significant difference compared to that in an alkali-metal system.

  15. Astrophysics of resonant orbits in the Kerr metric

    NASA Astrophysics Data System (ADS)

    Brink, Jeandrew; Geyer, Marisa; Hinderer, Tanja

    2015-04-01

    This paper gives a complete characterization of the location of resonant orbits in a Kerr spacetime for all possible black hole spins and orbital parameter values. A resonant orbit in this work is defined as a geodesic for which the longitudinal and radial orbital frequencies are commensurate. Our analysis is based on expressing the resonance condition in its most symmetric form using Carlson's elliptic integrals, which enable us to provide exact results together with a number of concise formulas characterizing the explicit dependence on the system parameters. The locations of resonant orbits identify regions where intriguing observable phenomena could occur in astrophysical situations when various sources of perturbation act on the binary system. Resonant effects may have observable implications for the inspirals of compact objects into a supermassive black hole. During a generic inspiral the slowly evolving orbital frequencies will pass through a series of low-order resonances where the ratio of orbital frequencies is equal to the ratio of two small integers. At these locations rapid changes in the orbital parameters could produce a measurable phase shift in the emitted gravitational and electromagnetic radiation. Resonant orbits may also capture gas or larger objects leading to further observable characteristic electromagnetic emission. According to the Kolmogorov-Arnold-Moser theorem, low-order resonant orbits demarcate the regions where the onset of geodesic chaos could occur when the Kerr Hamiltonian is perturbed. Perturbations are induced for example if the spacetime of the central object is non-Kerr, if gravity is modified, if the orbiting particle has large multipole moments, or if additional masses are nearby. We find that the 1 /2 and 2 /3 resonances occur at approximately 4 and 5.4 Schwarzschild radii (Rs) from the black hole's event horizon. For compact object inspirals into supermassive black holes (˜106M⊙ ) this region lies within the sensitivity

  16. A SECOND GIANT PLANET IN 3:2 MEAN-MOTION RESONANCE IN THE HD 204313 SYSTEM

    SciTech Connect

    Robertson, Paul; Endl, Michael; Cochran, William D.; MacQueen, Phillip J.; Brugamyer, Erik J.; Barnes, Stuart I.; Caldwell, Caroline; Horner, J.; Wittenmyer, Robert A.; Simon, Attila E.

    2012-07-20

    We present eight years of high-precision radial velocity (RV) data for HD 204313 from the 2.7 m Harlan J. Smith Telescope at McDonald Observatory. The star is known to have a giant planet (Msin i = 3.5 M{sub J} ) on a {approx}1900 day orbit, and a Neptune-mass planet at 0.2 AU. Using our own data in combination with the published CORALIE RVs of Segransan et al., we discover an outer Jovian (Msin i = 1.6 M{sub J} ) planet with P {approx} 2800 days. Our orbital fit suggests that the planets are in a 3:2 mean motion resonance, which would potentially affect their stability. We perform a detailed stability analysis and verify that the planets must be in resonance.

  17. Orbital order of spinless fermions near an optical Feshbach resonance

    SciTech Connect

    Hauke, Philipp; Zhao, Erhai; Goyal, Krittika; Deutsch, Ivan H.; Liu, W. Vincent; Lewenstein, Maciej

    2011-11-15

    We study the quantum phases of a three-color Hubbard model that arises in the dynamics of the p-band orbitals of spinless fermions in an optical lattice. Strong, color-dependent interactions are induced by an optical Feshbach resonance. Starting from the microscopic scattering properties of ultracold atoms, we derive the orbital exchange constants at 1/3 filling on the cubic optical lattice. Using this, we compute the phase diagram in a Gutzwiller ansatz. We find phases with ''axial orbital order'' in which p{sub z} and p{sub x}+ip{sub y} (or p{sub x}-ip{sub y}) orbitals alternate.

  18. How the presence of a gas giant affects the formation of mean-motion resonances between two low-mass planets in a locally isothermal gaseous disc

    NASA Astrophysics Data System (ADS)

    Podlewska-Gaca, E.; Szuszkiewicz, E.

    2014-03-01

    In this paper we investigate the possibility of a migration-induced resonance locking in systems containing three planets, namely an Earth analogue (1 M⊕), a super-Earth (4 M⊕) and a gas giant (one Jupiter mass). The planets have been listed in order of increasing orbital periods. All three bodies are embedded in a locally isothermal gaseous disc and orbit around a solar mass star. We are interested in answering the following questions: will the low-mass planets form the same resonant structures with each other in the vicinity of the gas giant as in the case when the gas giant is absent? More in general, how will the presence of the gas giant affect the evolution of the two low-mass planets? When there is no gas giant in the system, it has been already shown that if the two low-mass planets undergo a convergent differential migration, they will capture each other in a mean-motion resonance. For the choices of disc parameters and planet masses made in this paper, the formation of the 5:4 resonance in the absence of the Jupiter has been observed in a previous investigation and confirmed here. In this work we add a gas giant on the most external orbit of the system in such a way that its differential migration is convergent with the low-mass planets. We show that the result of this set-up is the speeding up of the migration of the super-Earth and, after that, all three planets become locked in a triple mean-motion resonance. However, this resonance is not maintained due to the low-mass planet eccentricity excitation, a fact that leads to close encounters between planets and eventually to the ejection from the internal orbits of one or both low-mass planets. We have observed that the ejected low-mass planets can leave the system, fall into a star or become the external planet relative to the gas giant. In our simulations the latter situation has been observed for the super-Earth. It follows from the results presented here that the presence of a Jupiter-like planet

  19. Pluto and Charon: A Case of Precession-Orbit Resonance?

    NASA Technical Reports Server (NTRS)

    Rubincam, David Parry; Smith, David E. (Technical Monitor)

    2000-01-01

    Pluto may be the only known case of precession-orbit resonance in the solar system. The Pluto-Charon system orbits the Sun with a period of 1 Plutonian year, which is 250.8 Earth years. The observed parameters of the system are such that Charon may cause Pluto to precess with a period near 250.8 Earth years. This gives rise to two possible resonances, heretofore unrecognized. The first is due to Pluto's orbit being highly eccentric, giving solar torques on Charon with a period of 1 Plutonian year. Charon in turn drives Pluto near its precession period. Volatiles, which are expected to shuttle across Pluto's surface between equator and pole as Pluto's obliquity oscillates, might change the planet's dynamical flattening enough so that Pluto crosses the nearby resonance, forcing the planet's equatorial plane to depart from Charon's orbital plane. The mutual tilt can reach as much as 2 deg after integrating over 5.6 x 10(exp 6) years, depending upon how close Pluto is to the resonance and the supply of volatiles. The second resonance is due to the Sun's traveling above and below Charon's orbital plane; it has a period half that of the eccentricity resonance. Reaching this half-Plutonian year resonance requires a much larger but still theoretically possible amount of volatiles. In this case the departure of Charon from an equatorial orbit is about 1 deg after integrating for 5.6 x 10(exp 6) years. The calculations ignore libration and tidal friction. It is not presently known how large the mutual tilt can grow over the age of the solar system, but if it remains only a few degrees, then observing such small angles from a Pluto flyby mission would be difficult. It is not clear why the parameters of the Pluto-Charon system are so close to the eccentricity resonance.

  20. Diagrammatic theory of transition of pendulum like systems. [orbit-orbit and spin-orbit gravitational resonance interactions

    NASA Technical Reports Server (NTRS)

    Yoder, C. F.

    1979-01-01

    Orbit-orbit and spin-orbit gravitational resonances are analyzed using the model of a rigid pendulum subject to both a time-dependent periodic torque and a constant applied torque. First, a descriptive model of passage through resonance is developed from an examination of the polynomial equation that determines the extremes of the momentum variable. From this study, a probability estimate for capture into libration is derived. Second, a lowest order solution is constructed and compared with the solution obtained from numerical integration. The steps necessary to systematically improve this solution are also discussed. Finally, the effect of a dissipative term in the pendulum equation is analyzed.

  1. Characteristics of vibration energy harvesting using giant magnetostrictive cantilevers with resonant tuning

    NASA Astrophysics Data System (ADS)

    Mori, Kotaro; Horibe, Tadashi; Ishikawa, Shigekazu; Shindo, Yasuhide; Narita, Fumio

    2015-12-01

    This work deals with the dynamic bending and energy harvesting characteristics of giant magnetostrictive cantilevers with resonant tuning both numerically and experimentally. The giant magnetostrictive cantilever is fabricated using a thin Terfenol-D layer, SUS layer, movable proof mass, etc, and, is designed to automatically adjust its own resonant frequency to match the external vibration frequency in real time. Three-dimensional finite element analysis was conducted, and the resonant frequency, induced voltage and stress in the magnetostrictive cantilevers were predicted. The resonant frequency and induced voltage were also measured, and comparison was made between simulation and experiment. The time-varying behavior and self-tuning ability are discussed in detail.

  2. HOW ECCENTRIC ORBITAL SOLUTIONS CAN HIDE PLANETARY SYSTEMS IN 2:1 RESONANT ORBITS

    SciTech Connect

    Anglada-Escude, Guillem; Chambers, John E.; Lopez-Morales, Mercedes E-mail: mercedes@dtm.ciw.ed

    2010-01-20

    The Doppler technique measures the reflex radial motion of a star induced by the presence of companions and is the most successful method to detect exoplanets. If several planets are present, their signals will appear combined in the radial motion of the star, leading to potential misinterpretations of the data. Specifically, two planets in 2:1 resonant orbits can mimic the signal of a single planet in an eccentric orbit. We quantify the implications of this statistical degeneracy for a representative sample of the reported single exoplanets with available data sets, finding that (1) around 35% of the published eccentric one-planet solutions are statistically indistinguishable from planetary systems in 2:1 orbital resonance, (2) another 40% cannot be statistically distinguished from a circular orbital solution, and (3) planets with masses comparable to Earth could be hidden in known orbital solutions of eccentric super-Earths and Neptune mass planets.

  3. Extrasolar Giant Planet in Earth-like Orbit

    NASA Astrophysics Data System (ADS)

    1999-07-01

    Discovery from a Long-term Project at La Silla A new extrasolar planet has been found at the ESO La Silla Observatory as a companion to iota Horologii (iota Hor) . This 5.4-mag solar-type star is located at a distance of 56 light-years and is just visible to the unaided eye in the southern constellation Horologium (The Pendulum Clock). The discovery is the result of a long-term survey of forty solar-type stars that was begun in November 1992. It is based on highly accurate measurements of stellar radial velocities, i.e. the speed with which a star moves along the line of sight. The presence of a planet in orbit around a star is inferred from observed, regular changes of this velocity, as the host star and its planet revolve around a common center of gravity. Since in all cases the star is much heavier than the planet, the resulting velocity variations of the star are always quite small. The team that found the new planet, now designated iota Hor b , consists of Martin Kürster , Michael Endl and Sebastian Els (ESO-Chile), Artie P. Hatzes and William D. Cochran (University of Texas, Austin, USA), and Stefan Döbereiner and Konrad Dennerl (Max-Planck-Institut für extraterrestrische Physik, Garching, Germany). Iodine cell provides very accurate velocity measurements iota Hor b represents the first discovery of an extrasolar planet with an ESO instrument [1]. The finding is based on data obtained with ESO's highest-resolution spectrograph, the Coudé Echelle Spectrometer (CES) at the 1.4-m Coudé Auxiliary Telescope (CAT). While this telescope has recently been decommissioned, the CES instrument is now coupled via an optical fiber link to the larger ESO 3.6-m telescope, thus permitting the continuation of this survey. The high precision radial velocity measurements that are necessary for a study of this type were achieved by means of a special calibration technique. It incorporates an iodine gas absorption cell and sophisticated data modelling. The cell is used like

  4. Dwarf spheroidal galaxies and resonant orbital coupling

    NASA Technical Reports Server (NTRS)

    Kuhn, J. R.; Miller, R. H.

    1989-01-01

    The structural properties of the dwarf spheroidal satellite galaxies of the Milky Way may be strongly affected by their time-dependent interactions with the 'tidal' field of the Milky Way. A low Q resonance of the tidal driving force with collective oscillation modes of the dwarf system can produce many of the observed properties of the Local Group dwarf spheroidal galaxies, including large velocity dispersions that would normally be interpreted as indicating large dynamical masses.

  5. Orbital evolution of asteroids near the secular resonance nu6

    NASA Astrophysics Data System (ADS)

    Froeschle, Ch.; Scholl, H.

    1987-06-01

    The authors investigate the orbital evolutions of numbered asteroids which are supposed to be located near the secular resonance ν6 according to Williams' list (1979). The asteroidal orbits are integrated numerically over 1 Myr in the four-body model Sun-Jupiter-Saturn-asteroid. Only the two asteroids (759) Vinifera and (1222) Tina are found to be located deeply in the ν6 secular resonance. The asteroid (2368) Beltovata is at present also situated in this secular resonance. Presumably, Beltovata will be removed from the resonance due to a close approach to Jupiter. Beltovata is a possible candidate to become an Apollo asteroid. The dynamical topology of the ν6 secular resonance seems to be similar to the mean motion resonance. The authors conjecture that also for the ν6 resonance, a separatrix-like region separates librators from circulators. Only those parts of the ν6 secular resonance region, where libration with large amplitudes occurs, have to be considered as possible sources of meteorites.

  6. The Use of Resonant Orbits in Satellite Geodesy: A Review

    NASA Astrophysics Data System (ADS)

    Klokočník, J.; Gooding, R. H.; Wagner, C. A.; Kostelecký, J.; Bezděk, A.

    2013-01-01

    Dynamic resonance, arising from commensurate (orbital or rotational) periods of satellites or planets with each other, has been a strong force in the development of the solar system. The repetition of conditions over the commensurate periods can result in amplified long-term changes in the positions of the bodies involved. Such resonant phenomena driven by the commensurability between the mean motion of certain artificial Earth satellites and the Earth's rotation originally contributed to the evaluation and assessment of the Stokes parameters (harmonic geopotential coefficients) that specify the Earth's gravitational field. The technique constrains linear combinations of the harmonic coefficients that are of relevant resonant order (lumped coefficients). The attraction of the method eventually dwindled, but the very accurate orbits of CHAMP and GRACE have recently led to more general insights for commensurate orbits applied to satellite geodesy involving the best resolution for all coefficients, not just resonant ones. From the GRACE mission, we learnt how to explain and predict temporary decreases in the resolution and accuracy of derived geopotential parameters, due to passages through low-order commensurabilities, which lead to low-density ground-track patterns. For GOCE we suggest how to change a repeat orbit height slightly, to achieve the best feasible recovery of the field parameters derived from on-board gradiometric measurements by direct inversion from the measurements to the harmonic geopotential coefficients, not by the way of lumped coefficients. For orbiters of Mars, we have suggestions which orbits should be avoided. The slow rotation of Venus results in dense ground-tracks and excellent gravitational recovery for almost all orbiters.

  7. Dynamical sequestration of the Moon-forming impactor in co-orbital resonance with Earth

    NASA Astrophysics Data System (ADS)

    Kortenkamp, Stephen J.; Hartmann, William K.

    2016-09-01

    Recent concerns about the giant impact hypothesis for the origin of the Moon, and an associated "isotope crisis" may be assuaged if the impactor was a local object that formed near Earth. We investigated a scenario that may meet this criterion, with protoplanets assumed to originate in 1:1 co-orbital resonance with Earth. Using N-body numerical simulations we explored the dynamical consequences of placing Mars-mass companions in various co-orbital configurations with a proto-Earth of 0.9 Earth-masses (M⊕). We modeled 162 different configurations, some with just the four terrestrial planets and others that included the four giant planets. In both the 4- and 8-planet models we found that a single Mars-mass companion typically remained a stable co-orbital of Earth for the entire 250 million year (Myr) duration of our simulations (59 of 68 unique simulations). In an effort to destabilize such a system we carried out an additional 94 simulations that included a second Mars-mass co-orbital companion. Even with two Mars-mass companions sharing Earth's orbit about two-thirds of these models (66) also remained stable for the entire 250 Myr duration of the simulations. Of the 28 2-companion models that eventually became unstable 24 impacts were observed between Earth and an escaping co-orbital companion. The average delay we observed for an impact of a Mars-mass companion with Earth was 102 Myr, and the longest delay was 221 Myr. In 40% of the 8-planet models that became unstable (10 out of 25) Earth collided with the nearly equal mass Venus to form a super-Earth (loosely defined here as mass ≥1.7 M⊕). These impacts were typically the final giant impact in the system and often occurred after Earth and/or Venus has accreted one or more of the other large objects. Several of the stable configurations involved unusual 3-planet hierarchical co-orbital systems.

  8. Dynamical coupling of pygmy and giant resonances in relativistic Coulomb excitation

    NASA Astrophysics Data System (ADS)

    Brady, N. S.; Aumann, T.; Bertulani, C. A.; Thomas, J. O.

    2016-06-01

    We study the Coulomb excitation of pygmy dipole resonances (PDR) in heavy ion reactions at 100 MeV/nucleon and above. The reactions 68Ni +197Au and 68Ni +208Pb are taken as practical examples. Our goal is to address the question of the influence of giant resonances on the PDR as the dynamics of the collision evolves. We show that the coupling to the giant resonances affects considerably the excitation probabilities of the PDR, a result that indicates the need of an improved theoretical treatment of the reaction dynamics at these bombarding energies.

  9. Spin-Orbit Coupled Fermi Gases across a Feshbach Resonance

    NASA Astrophysics Data System (ADS)

    Yu, Zeng-Qiang; Zhai, Hui

    2011-11-01

    In this Letter we study both ground state properties and the superfluid transition temperature of a spin-1/2 Fermi gas across a Feshbach resonance with a synthetic spin-orbit coupling, using the mean-field theory and the exact solution of two-body problem. We show that a strong spin-orbit coupling can significantly enhance the pairing gap for negative scattering length as, due to increased density of state at Fermi surface. Strong spin-orbit coupling can also significantly enhance the superfluid transition temperature Tc to a sizable fraction of Fermi temperature when as≲0, while it suppresses Tc slightly for positive as. The interaction energy and pair size at resonance are also discussed.

  10. Charged dust dynamics - Orbital resonance due to planetary shadows

    NASA Technical Reports Server (NTRS)

    Horanyi, M.; Burns, J. A.

    1991-01-01

    The dynamics of a weakly charged dust grain orbiting in the equatorial plane of a planet surrounded by a rigidly corotating magnetospehre is examined. It is shown that an introduction of an effectilve 1D potential causes a perturbation due to electrostatic forces, which induces a motion of the pericenter, similar to the effect of the planetary oblateness. A case is examined where the charge varies periodically due to the modulation of the photoelectron current occurring as the grain enters and leaves the planetary shadow, causing the electromagnetic perturbation to resonate with the orbital period and to modify the size and eccentricity of the orbit. This effect is demonstrated both numerically and analytically for small grains comprising the Jovian ring, showing that their resulting changes are periodic, and their amplitude is much larger than that of the periodic changes due to light-pressure perturbation or the secular changes due to resonant charge variations that develop over a comparable time span.

  11. Resonant Orbits and the High Velocity Peaks toward the Bulge

    NASA Astrophysics Data System (ADS)

    Molloy, Matthew; Smith, Martin C.; Evans, N. Wyn; Shen, Juntai

    2015-10-01

    We extract the resonant orbits from an N-body bar that is a good representation of the Milky Way, using the method recently introduced by Molloy et al. By decomposing the bar into its constituent orbit families, we show that they are intimately connected to the boxy-peanut shape of the density. We highlight the imprint due solely to resonant orbits on the kinematic landscape toward the Galactic center. The resonant orbits are shown to have distinct kinematic features and may be used to explain the cold velocity peak seen in the Apache Point Observatory Galactic Evolution Experiment commissioning data. We show that high velocity peaks are a natural consequence of the motions of stars in the 2:1 orbit family and that stars on other higher order resonances can contribute to the peaks. The locations of the peaks vary with bar angle and, with the tacit assumption that the observed peaks are due to the 2:1 family, we find that the locations of the high velocity peaks correspond to bar angles in the range {10}\\circ ≲ {θ }{bar}≲ 25^\\circ . However, some important questions about the nature of the peaks remain, such as their apparent absence in other surveys of the Bulge and the deviations from symmetry between equivalent fields in the north and south. We show that the absence of a peak in surveys at higher latitudes is likely due to the combination of a less prominent peak and a lower number density of bar supporting orbits at these latitudes.

  12. Giant Kerr nonlinearity via tunneling induced double dark resonances in triangular quantum dot molecules

    NASA Astrophysics Data System (ADS)

    Tian, Si-Cong; Wan, Ren-Gang; Tong, Cun-Zhu; Fu, Xi-Hong; Cao, Jun-Sheng; Ning, Yong-Qiang

    2015-12-01

    A scheme for giant Kerr nonlinearity via tunneling in triangular triple quantum dot molecules is proposed. In such a system, the linear absorption and the Kerr nonlinearity depend critically on the energy splitting of the excited states and the tunneling intensity. With proper parameters, giant Kerr nonlinearity accompanied by vanishing absorption can be realized. The enhancement of Kerr nonlinearity is attributed to the interacting double dark resonances induced by the tunneling between the quantum dots, requiring no extra coupling laser fields.

  13. Magnetization switching through giant spin-orbit torque in a magnetically doped topological insulator heterostructure

    NASA Astrophysics Data System (ADS)

    Fan, Yabin; Upadhyaya, Pramey; Kou, Xufeng; Lang, Murong; Takei, So; Wang, Zhenxing; Tang, Jianshi; He, Liang; Chang, Li-Te; Montazeri, Mohammad; Yu, Guoqiang; Jiang, Wanjun; Nie, Tianxiao; Schwartz, Robert N.; Tserkovnyak, Yaroslav; Wang, Kang L.

    2014-07-01

    Recent demonstrations of magnetization switching induced by in-plane current in heavy metal/ferromagnetic heterostructures (HMFHs) have drawn great attention to spin torques arising from large spin-orbit coupling (SOC). Given the intrinsic strong SOC, topological insulators (TIs) are expected to be promising candidates for exploring spin-orbit torque (SOT)-related physics. Here we demonstrate experimentally the magnetization switching through giant SOT induced by an in-plane current in a chromium-doped TI bilayer heterostructure. The critical current density required for switching is below 8.9 × 104 A cm-2 at 1.9 K. Moreover, the SOT is calibrated by measuring the effective spin-orbit field using second-harmonic methods. The effective field to current ratio and the spin-Hall angle tangent are almost three orders of magnitude larger than those reported for HMFHs. The giant SOT and efficient current-induced magnetization switching exhibited by the bilayer heterostructure may lead to innovative spintronics applications such as ultralow power dissipation memory and logic devices.

  14. THE PAN-PACIFIC PLANET SEARCH. I. A GIANT PLANET ORBITING 7 CMa

    SciTech Connect

    Wittenmyer, Robert A.; Tinney, C. G.; Endl, Michael; Wang Liang; Johnson, John Asher; O'Toole, S. J.

    2011-12-20

    We introduce the Pan-Pacific Planet Search, a survey of 170 metal-rich Southern Hemisphere subgiants using the 3.9 m Anglo-Australian Telescope. We report the first discovery from this program, a giant planet orbiting 7 CMa (HD 47205) with a period of 763 {+-} 17 days, eccentricity e = 0.14 {+-} 0.06, and msin i = 2.6 {+-} 0.6 M{sub Jup}. The host star is a K giant with a mass of 1.5 {+-} 0.3 M{sub Sun} and metallicity [Fe/H] = 0.21 {+-} 0.10. The mass and period of 7 CMa b are typical of planets which have been found to orbit intermediate-mass stars (M{sub *} > 1.3 M{sub Sun }). Hipparcos photometry shows this star to be stable to 0.0004 mag on the radial-velocity period, giving confidence that this signal can be attributed to reflex motion caused by an orbiting planet.

  15. E2 giant resonances and an M1 component in the photofission of /sup 236/U

    SciTech Connect

    Arruda-Neto, J.D.T.; Herdade, S.B.; Berman, B.L.; Nascimento, I.C.

    1980-11-01

    Electrofission and photofission yields and electrofission-fragment angular distributions for /sup 236/U have been measured with fission-track detectors for incident electron energies from 5.5 to 33.0 MeV. Analysis of these data with the use of virtual-photon spectra calculated in distorted-wave Born approximation, combined with the known photofission cross section, results in the simultaneous determination for this nucleus of (a) a giant isoscalar E2 resonance located at 10.8 +- 0.4 MeV, having a width of 6 +- 1 MeV, and exhausting approx.70% of the isoscalar energy-weighted sum rule, and (b) a small M1 component located at 5.8 +- 0.2 MeV whose strength is <2% of that of the giant isoscalar E2 resonance. No evidence is seen for a giant isovector E2 resonance between 22 and 30 MeV.

  16. Attosecond delay of xenon 4 d photoionization at the giant resonance and Cooper minimum

    NASA Astrophysics Data System (ADS)

    Magrakvelidze, Maia; Madjet, Mohamed El-Amine; Chakraborty, Himadri S.

    2016-07-01

    A Kohn-Sham time-dependent local-density-functional scheme is utilized to predict attosecond time delays of xenon 4 d photoionization that involves the 4 d giant dipole resonance and Cooper minimum. The fundamental effect of electron correlations to uniquely determine the delay at both regions is demonstrated. In particular, for the giant dipole resonance, the delay underpins strong collective effect, emulating the recent prediction at C60 giant plasmon resonance [T. Barillot et al., Phys. Rev. A 91, 033413 (2015), 10.1103/PhysRevA.91.033413]. For the Cooper minimum, a qualitative similarity with a photorecombination experiment near argon 3 p minimum [S. B. Schoun et al., Phys. Rev. Lett. 112, 153001 (2014), 10.1103/PhysRevLett.112.153001] is found. The result should encourage attosecond measurements of Xe 4 d photoemission.

  17. Study of dynamical processes at the final stages of planetary system formation: Resonance motion of giant planets

    NASA Astrophysics Data System (ADS)

    Emel'yanenko, V. V.

    2012-09-01

    According to current observational data, planets of many exoplanetary systems have resonant motion. The formation of resonance configurations is studied within a unified model of planetary migration. Planets in the observed systems 24 Sex, HD 37124, HD 73526, HD 82943, HD 128311, HD 160691, Kepler 9, NN Ser, which are moving in the 2: 1 resonance, could have been captured into this resonance due to both the Type I and II migration with a wide range of parameters. The migration conditions are defined for the formation of HD 45364 and HD 200964 that are in the 3: 2 and 4: 3 first-order resonances, correspondingly. The results obtained for HD 200964 show that planets can be captured in the first-order resonances, when the outer-to-inner orbital period ratios for the planets are less than 3: 2, only if Type I migration rates are large, and the mass of at least one planet is substantially less than the modern masses of the observed giant planets. The formation of the HD 102272, HD 108874, HD 181433 and HD 202206 systems with planets in high-order resonances is considered. The capture into these resonances can be realized with very slow Type II migration. Possible bounds for migration parameters are considered. In particular, it has been found that the capture of HD 108874 into the 4: 1 resonance is possible only if the angle between the plane of planetary orbits and the plane of sky is appreciably less than 90°, i.e., the planetary masses are a few times larger than the minimum values. The capture of HD 202206 into the 5: 1 resonance is possible at low migration rates; however, another mechanism is required to explain the high observed eccentricity of the inner planet (for example, strong gravitational interaction between the planets). Resonant configurations can be disrupted due to the interaction between planets and remaining fragments of the planetesimal disk as, for example, may occur in the three-planet system 47 UMa. The specific orbital features observed for

  18. Extreme nuclear shapes examined via giant dipole resonance lineshapes in hot light-mass systems

    SciTech Connect

    Pandit, Deepak; Mukhopadhyay, S.; Pal, Surajit; Bhattacharya, S.; Bhattacharya, C.; Banerjee, K.; Kundu, S.; Rana, T. K.; Dey, A.; Mukherjee, G.; Ghosh, T.; Banerjee, S. R.; De, A.; Gupta, D.

    2010-06-15

    The influence of alpha clustering on nuclear reaction dynamics is investigated using the giant dipole resonance (GDR) lineshape studies in the reactions {sup 20}Ne (E{sub lab}=145,160 MeV) + {sup 12}C and {sup 20}Ne (E{sub lab}=160 MeV) + {sup 27}Al, populating {sup 32}S and {sup 47}V, respectively. The GDR lineshapes from the two systems are remarkably different from each other. Whereas, the non-alpha-like {sup 47}V undergoes Jacobi shape transition and matches exceptionally well with the theoretical GDR lineshape estimated under the framework rotating liquid drop model (RLDM) and thermal shape fluctuation model (TSFM) signifying shape equilibration, for the alpha cluster {sup 32}S an extended prolate kind of shape is observed. This unusual deformation, seen directly via gamma decay for the first time, is predicted to be due to the formation of orbiting dinuclear configuration or molecular structure of {sup 16}O + {sup 16}O in the {sup 32}S superdeformed band.

  19. Synchronous spin-orbital resonance locking of large planetary satellites

    NASA Astrophysics Data System (ADS)

    Aleshkina, E. Yu.

    2009-02-01

    A numerical investigation of the chaotic rotation of large planetary satellites before their synchronous spin-orbital resonance locking with regard to tidal friction is carried out. The rotational dynamics of seven large satellites greater than 1000 km in diameter and with known inertial parameters (Io, Europa, Ganymede, Callisto (J1 J4), Tethys (S3), Iapetus (S8), and Ariel (U1)) in the epoch of synchronous resonance locking is modeled. All of these satellites have a small dynamic asymmetry. The planar case is considered in which the satellite’s axis of rotation is orthogonal to the plane of orbit. The satellites possessing an initial rapid rotation pass through various resonant states during the tidal evolution. Here, the probability of their locking into these states exists. The numerical experiments presented in this paper have shown that, with a rather high arbitrariness in the choice of initial states, the satellites during the course of the tidal evolution of their rotational motion have passed without interruption through the regions of the 5: 2, 2: 1, and 3: 2 resonances in the phase space and are locked into the 1: 1 resonance. The estimate for the tidal deceleration time is obtained both theoretically and on the numerical experimental basis.

  20. Excitation and photon decay of giant multipole resonances - the role and future of medium-energy heavy ions

    SciTech Connect

    Bertrand, F.E.; Beene, J.R.; Horen, D.J.

    1988-01-01

    Inelastic scattering of medium energy heavy ions provides very large cross sections and peak-to-continuum ratios for excitation of giant resonances. For energies above about 50 MeV/nucleon, giant resonances are excited primarily through Coulomb excitation, which is indifferent to isospin, thus providing a good probe for the study of isovector giant resonances. The extremely large cross sections available from heavy ion excitation permit the study of rare decay modes of the photon decay of giant resonances following excitation by 22 and 84 MeV/nucleon /sup 17/O projectiles. The singles results at 84 MeV/nucleon yield peak cross sections for the isoscalar giant quadrupole resonance and the isovector giant dipole resonance of approximately 0.8 and 3 barns/sr, respectively. Data on the ground state decay of the isoscalar giant quadrupole and isovector giant dipole resonances are presented and compared with calculations. Decays to low-lying excited states are also discussed. Preliminary results from an experiment to isolate the /sup 208/Pb isovector quadrupole resonance using its gamma decay are presented.

  1. Giant myxofibrosarcoma of the orbit: a rare case and a review of the literature.

    PubMed

    Meel, Rachna; Lokdarshi, Gautam; Kashyap, Seema; Sharma, Sanjay

    2016-01-01

    A 65-year-old man presented with giant orbital myxofibrosarcoma with no extraorbital extension. Imaging was suggestive of mesenchymal malignancy with significant vascularity. Incisional biopsy was suggestive of low-grade fibromyxoid sarcoma. The clinical and imaging features did not support the pathological diagnosis. Histopathology of the exenterated sample revealed features of high-grade myxofibrosarcoma. To the best of our knowledge, this is the largest reported myxofibrosarcoma of the orbit. Adjuvant radiotherapy was advised. Correlating the case history, imaging and histopathology, this case can best be summarised as a natural history of conversion from a low to high-grade myxoid malignancy. We emphasise that the overlapping features of myxoid malignancy (fibromyxosarcoma vs myxofibrosarcoma) and regional variation in tumour morphology in biopsy specimen may mislead the clinician. Therefore, knowledge about the key differentiating features as well as incisional biopsy of each radiologically different area can increase the possibility of correct diagnosis and management of each case. PMID:27298287

  2. N-BODY SIMULATIONS OF SATELLITE FORMATION AROUND GIANT PLANETS: ORIGIN OF ORBITAL CONFIGURATION OF THE GALILEAN MOONS

    SciTech Connect

    Ogihara, Masahiro; Ida, Shigeru E-mail: ida@geo.titech.ac.jp

    2012-07-01

    As the number of discovered extrasolar planets has been increasing, diversity of planetary systems requires studies of new formation scenarios. It is important to study satellite formation in circumplanetary disks, which is often viewed as analogous to formation of rocky planets in protoplanetary disks. We investigated satellite formation from satellitesimals around giant planets through N-body simulations that include gravitational interactions with a circumplanetary gas disk. Our main aim is to reproduce the observable properties of the Galilean satellites around Jupiter through numerical simulations, as previous N-body simulations have not explained the origin of the resonant configuration. We performed accretion simulations based on the work of Sasaki et al., in which an inner cavity is added to the model of Canup and Ward. We found that several satellites are formed and captured in mutual mean motion resonances outside the disk inner edge and are stable after rapid disk gas dissipation, which explains the characteristics of the Galilean satellites. In addition, owing to the existence of the disk edge, a radial compositional gradient of the Galilean satellites can also be reproduced. An additional objective of this study is to discuss orbital properties of formed satellites for a wide range of conditions by considering large uncertainties in model parameters. Through numerical experiments and semianalytical arguments, we determined that if the inner edge of a disk is introduced, a Galilean-like configuration in which several satellites are captured into a 2:1 resonance outside the disk inner cavity is almost universal. In fact, such a configuration is produced even for a massive disk {approx}> 10{sup 4} g cm{sup -2} and rapid type I migration. This result implies the inevitability of a Galilean satellite formation in addition to providing theoretical predictions for extrasolar satellites. That is, we can predict a substantial number of exomoon systems in the 2

  3. SHOCKS AND A GIANT PLANET IN THE DISK ORBITING BP PISCIUM?

    SciTech Connect

    Melis, C.; Zuckerman, B.; Gielen, C.; Chen, C. H.; Rhee, Joseph H.; Song, Inseok

    2010-11-20

    Spitzer Infrared Spectrograph data support the interpretation that BP Piscium, a gas and dust enshrouded star residing at high Galactic latitude, is a first-ascent giant rather than a classical T Tauri star. Our analysis suggests that BP Piscium's spectral energy distribution can be modeled as a disk with a gap that is opened by a giant planet. Modeling the rich mid-infrared emission line spectrum indicates that the solid-state emitting grains orbiting BP Piscium are primarily composed of {approx}75 K crystalline, magnesium-rich olivine; {approx}75 K crystalline, magnesium-rich pyroxene; {approx}200 K amorphous, magnesium-rich pyroxene; and {approx}200 K annealed silica (cristobalite). These dust grains are all sub-micron sized. The giant planet and gap model also naturally explains the location and mineralogy of the small dust grains in the disk. Disk shocks that result from disk-planet interaction generate the highly crystalline dust which is subsequently blown out of the disk mid-plane and into the disk atmosphere.

  4. Magnetization switching through giant spin-orbit torque in the magnetically doped topological insulators

    NASA Astrophysics Data System (ADS)

    Fan, Yabin

    2015-03-01

    Recent demonstrations of magnetization switching induced by in-plane current in heavy metal/ferromagnetic heterostructures (HMFHs) have drawn great interest to spin torques arising from the large spin-orbit coupling (SOC)... in heavy metals. Considering the intrinsic strong SOC, topological insulators (TIs) are expected to be promising candidates for exploring spin-orbit torque (SOT)-related physics.... In this talk, we report the magnetization switching through giant SOT in the magnetically doped TI structures. In particular, we demonstrate the magnetization switching in a chromium-doped TI bilayer heterostructure, and the current induced SOT possibly has contribution from the spin-momentum locked surface states of TI. The critical current density for switching is below 8.9 × 104A/cm2 at 1.9 K. Moreover, we use second-harmonic methods to measure the spin torque efficiencies which are more than three orders of magnitude larger than those reported in heavy metals. The giant SOT and efficient current-induced magnetization switching exhibited by the bilayer heterostructure may lead to innovative spintronics applications such as ultralow power dissipation memory and logic devices. We are grateful to the support from the DARPA Meso program under Contract No. N66001-12-1-4034 and N66001-11-1-4105. We also acknowledge the support from the Western Institute of Nanoelectronics (WIN) and the support from the FAME center.

  5. DETECTION OF A GIANT EXTRASOLAR PLANET ORBITING THE ECLIPSING POLAR DP LEO

    SciTech Connect

    Qian, S.-B.; Liao, W.-P.; Zhu, L.-Y.; Dai, Z.-B.

    2010-01-01

    DP Leo is the first discovered eclipsing polar with a short period of 1.4967 hours. The period variation of the eclipsing binary was analyzed by using five new determined eclipse times together with those compiled from the literature. It is discovered that the O - C curve of DP Leo shows a cyclic variation with a period of 23.8 years and a semiamplitude of 31.5 s. The small-amplitude periodic change can be plausibly explained as the light-travel time effect due to the presence of a tertiary companion. The mass of the tertiary component is determined to be M {sub 3}sin i' = 0.00600({+-}0.00055) M {sub sun} = 6.28({+-}0.58) M {sub Jupiter} when a total mass of 0.69 M {sub sun} is adopted. If the tertiary companion is coplanar to the eclipsing binary (i.e., i' = 79.{sup 0}5), it should be a giant extrasolar planet with a mass of 6.39 M {sub Jupiter} at a distance of 8.6 astronomical units to the central binary. One of the most interesting things that we have learned about extrasolar planets over the last 17 years is that they can exist almost anywhere. The detection of a giant planet orbiting a polar would provide insight into the formation and evolution of circumbinary planets (planets orbiting both components of short-period binaries) as well as the late evolution of binary stars.

  6. Observation of global electromagnetic resonances by low- orbiting satellites

    NASA Astrophysics Data System (ADS)

    Surkov, V. V.

    2016-02-01

    Penetration of Schumann resonances energy from the Earth-ionosphere resonance cavity into the circumterrestrial space is examined. This study focuses on estimates of Alfvén wave amplitude and spectra in the frequency range of 7-50 Hz which can be observed by low-orbiting satellites. Differences in Schumann resonances observation conditions between the nighttime and sunlit sides of the ionosphere are analyzed. Particular emphasis has been placed on the ionospheric Alfvén resonator (IAR) excited by both global thunderstorm activity and individual lightning discharges. IAR spectra in the frequency range of 0.5-10 Hz are calculated for ionospheric altitudes. The calculated spectral amplitudes of IAR and Schumann resonances are compatible with C/NOFS satellite observations. To explain a shift of IAR resonant frequencies observed during C/NOFS satellite passage through terminator region, the IAR model is developed in which an interference of Alfvén waves reflected from the ionospheric E-layer and the IAR upper boundary is taken into account.

  7. Relativistic effects on giant resonances in electron-impact double ionization

    SciTech Connect

    Pindzola, M.S.

    1987-06-01

    The electron-impact double-ionization cross section for Fr/sup +/ is calculated in the distorted-wave Born approximation. A giant resonance in the 5d subshell ionization-autoionization contribution to the cross section is found to be quite sensitive to changes in the double-well potential caused by relativistic effects on bound-state wave functions.

  8. The Isoscalar Giant Dipole Resonance in {sup 20}Pb, {sup 90}Zr and the Nuclear Compressibility

    SciTech Connect

    Yildirim, Serbulent; Koeroglu, Ulas

    2008-11-11

    The isoscalar giant dipol resonance (ISGDR) in finite nuclei is studied within the framework of a relativistic transport approach. The excitation energies of spherical {sup 90}Zr and {sup 208}Pb nuclei are obtained for different quantum hydrodynamical Lagrangian parametrization. The sensitivity of ISGDR excitation energy on the nuclear bulk to surface properties are also investigated.

  9. Self-gravity, Resonances, and Orbital Diffusion in Stellar Disks

    NASA Astrophysics Data System (ADS)

    Fouvry, Jean-Baptiste; Binney, James; Pichon, Christophe

    2015-06-01

    Fluctuations in a stellar system's gravitational field cause the orbits of stars to evolve. The resulting evolution of the system can be computed with the orbit-averaged Fokker-Planck equation once the diffusion tensor is known. We present the formalism that enables one to compute the diffusion tensor from a given source of noise in the gravitational field when the system's dynamical response to that noise is included. In the case of a cool stellar disk we are able to reduce the computation of the diffusion tensor to a one-dimensional integral. We implement this formula for a tapered Mestel disk that is exposed to shot noise and find that we are able to explain analytically the principal features of a numerical simulation of such a disk. In particular the formation of narrow ridges of enhanced density in action space is recovered. As the disk's value of Toomre's Q is reduced and the disk becomes more responsive, there is a transition from a regime of heating in the inner regions of the disk through the inner Lindblad resonance to one of radial migration of near-circular orbits via the corotation resonance in the intermediate regions of the disk. The formalism developed here provides the ideal framework in which to study the long-term evolution of all kinds of stellar disks.

  10. The orbital evolution of asteroids, pebbles and planets from giant branch stellar radiation and winds

    NASA Astrophysics Data System (ADS)

    Veras, Dimitri; Eggl, Siegfried; Gänsicke, Boris T.

    2015-08-01

    The discovery of over 50 planets around evolved stars and more than 35 debris discs orbiting white dwarfs highlight the increasing need to understand small body evolution around both early and asymptotic giant branch (GB) stars. Pebbles and asteroids are susceptible to strong accelerations from the intense luminosity and winds of GB stars. Here, we establish equations that can model time-varying GB stellar radiation, wind drag and mass-loss. We derive the complete three-dimensional equations of motion in orbital elements due to (1) the Epstein and Stokes regimes of stellar wind drag, (2) Poynting-Robertson drag, and (3) the Yarkovsky drift with seasonal and diurnal components. We prove through averaging that the potential secular eccentricity and inclination excitation due to Yarkovsky drift can exceed that from Poynting-Robertson drag and radiation pressure by at least three orders of magnitude, possibly flinging asteroids which survive YORP spin-up into a widely dispersed cloud around the resulting white dwarf. The GB Yarkovsky effect alone may change an asteroid's orbital eccentricity by 10 per cent in just 1 Myr. Damping perturbations from stellar wind drag can be just as extreme, but are strongly dependent on the highly uncertain local gas density and mean free path length. We conclude that GB radiative and wind effects must be considered when modelling the post-main-sequence evolution of bodies smaller than about 1000 km.

  11. A mechanism for orbital angular momentum and giant spin-splitting in solids and nanostructures

    NASA Astrophysics Data System (ADS)

    Oh, Sehoon; Choi, Hyoung Joon

    Giant spin-splitting (GSS) of electronic bands, which is several orders of magnitude greater than Rashba model, has been observed in various systems including noble-metal surfaces, thin film of transition-metal dichalcogenides, often accompanied by the orbital angular momentum (OAM). Here, we study structural and orbital conditions for emergence of a GSS by using tight-binding and first-principles calculations. We find that broken mirror symmetry of local atomic structure around an atom can produce non-zero OAM at the atom. This OAM results in a GSS if the atom is a high-atomic number element. We demonstrate these structural and orbital conditions in the cases of simple atomic chains, WSe2 monolayer, Au(111) surface, and bulk HgTe. Based on this mechanism of the spin-splitting, we suggest methods to control the GSS, which can be used in applications such as spintronic devices. This work was supported by NRF of KOREA (Grant No. 2011-0018306) and KISTI supercomputing center (Project No. KSC-2015-C3-039).

  12. Splitting of the isovector giant dipole resonance in neutron-rich spherical nuclei

    SciTech Connect

    Kolomietz, V.M.; Magner, A.G.; Shlomo, S.

    2006-02-15

    The well-known splitting of the isovector giant dipole resonance is traditionally explained as a phenomenon of the nuclear isospin asymmetry (isospin splitting model) or the nuclear deformation. We suggest a new mechanism of the splitting of the giant multipole resonances in spherical neutron-rich nuclei resulting from the interplay of the isovector and isoscalar sounds with different velocities. Our approach is based on the collisional Landau kinetic theory and can be used for description of the splitting phenomena for both the isoscalar and the isovector modes in a wide region of nuclear masses A{approx}40-240. For the isovector dipole modes, the evaluated values of the splitting energy, the relative strength of the main and satellite resonance peaks, and the contribution to the energy-weighted sum rule are in agreement with experimental data.

  13. Coupled-Channel Models of Direct-Semidirect Capture via Giant-Dipole Resonances

    SciTech Connect

    Thompson, I J; Escher, Jutta E; Arbanas, Goran

    2013-01-01

    Semidirect capture, a two-step process that excites a giant-dipole resonance followed by its radiative de-excitation, is a dominant process near giant-dipole resonances, that is, for incoming neutron energies within 5 20 MeV. At lower energies such processes may affect neutron capture rates that are relevant to astrophysical nucleosynthesis models. We implement a semidirect capture model in the coupled-channel reaction code Fresco and validate it by comparing the cross section for direct-semidirect capture 208Pb(n,g)209Pb to experimental data. We also investigate the effect of low-energy electric dipole strength in the pygmy resonance. We use a conventional single-particle direct-semidirect capture code Cupido for comparison. Furthermore, we present and discuss our results for direct-semidirect capture reaction 130Sn(n,g)131Sn, the cross section of which is known to have a significant effect on nucleosynthesis models.

  14. Coupled-Channel Models of Direct-Semidirect Capture via Giant-Dipole Resonances

    NASA Astrophysics Data System (ADS)

    Thompson, I. J.; Escher, J. E.; Arbanas, G.

    2014-04-01

    Semidirect capture, a two-step process that excites a giant-dipole resonance followed by its radiative de-excitation, is a dominant process near giant-dipole resonances, that is, for incoming neutron energies within 5-20 MeV. At lower energies such processes may affect neutron capture rates that are relevant to astrophysical nucleosynthesis models. We implement a semidirect capture model in the coupled-channel reaction code Fresco and validate it by comparing the cross section for direct-semidirect capture 208Pb(n,γ)209Pb to experimental data. We also investigate the effect of low-energy electric dipole strength in the pygmy resonance. We use a conventional single-particle direct-semidirect capture code Cupido for comparison. Furthermore, we present and discuss our results for direct-semidirect capture reaction 130Sn(n,γ)131Sn, the cross section of which is known to have a significant effect on nucleosynthesis models.

  15. Isoscalar and isovector giant resonances in a self-consistent phonon coupling approach

    NASA Astrophysics Data System (ADS)

    Lyutorovich, N.; Tselyaev, V.; Speth, J.; Krewald, S.; Grümmer, F.; Reinhard, P.-G.

    2015-10-01

    We present fully self-consistent calculations of isoscalar giant monopole and quadrupole as well as isovector giant dipole resonances in heavy and light nuclei. The description is based on Skyrme energy-density functionals determining the static Hartree-Fock ground state and the excitation spectra within random-phase approximation (RPA) and RPA extended by including the quasiparticle-phonon coupling at the level of the time-blocking approximation (TBA). All matrix elements were derived consistently from the given energy-density functional and calculated without any approximation. As a new feature in these calculations, the single-particle continuum was included thus avoiding the artificial discretization usually implied in RPA and TBA. The step to include phonon coupling in TBA leads to small, but systematic, down shifts of the centroid energies of the giant resonances. These shifts are similar in size for all Skyrme parametrizations investigated here. After all, we demonstrate that one can find Skyrme parametrizations which deliver a good simultaneous reproduction of all three giant resonances within TBA.

  16. Giant spin Nernst effect induced by resonant scattering at surfaces of metallic films

    NASA Astrophysics Data System (ADS)

    Long, Nguyen H.; Mavropoulos, Phivos; Zimmermann, Bernd; Blügel, Stefan; Mokrousov, Yuriy

    2016-05-01

    A concept realizing giant spin Nernst effect in nonmagnetic metallic films is introduced. It is based on the idea of engineering an asymmetric energy dependence of the longitudinal and transverse electrical conductivities, as well as a pronounced energy dependence of the spin Hall angle in the vicinity of the Fermi level by the resonant impurity states at the Fermi level. We employ an analytical model and demonstrate the emergence of a giant spin Nernst effect in Ag(111) films using ab initio calculations combined with the Boltzmann approach for transport properties arising from skew scattering off impurities.

  17. Harmonic trap resonance enhanced synthetic atomic spin-orbit coupling

    NASA Astrophysics Data System (ADS)

    Wu, Ling-Na; Luo, Xinyu; Xu, Zhi-Fang; Ueda, Masahito; Wang, Ruquan; You, Li

    2016-05-01

    The widely adopted scheme for synthetic atomic spin-orbit coupling (SOC) is based on the momentum sensitive Raman coupling, which is easily implemented in one spatial dimension. Recently, schemes based on pulsed or periodically modulating gradient magnetic field (GMF) were proposed and the main characteristic features have subsequently been demonstrated. The present work reports an experimental discovery and the associated theoretical understanding of tuning the SOC strength synthesized with GMF through the motional resonance of atomic center-of-mass in a harmonic trap. In some limits, we observe up to 10 times stronger SOC compared to the momentum impulse from GMF for atoms in free space.

  18. Broad search for unstable resonant orbits in the planar circular restricted three-body problem

    NASA Astrophysics Data System (ADS)

    Anderson, Rodney L.; Campagnola, Stefano; Lantoine, Gregory

    2016-02-01

    Unstable resonant orbits in the circular restricted three-body problem have increasingly been used for trajectory design using optimization and invariant manifold techniques. In this study, several methods for computing these unstable resonant orbits are explored including grid searches, flyby maps, and continuation. Families of orbits are computed focusing on orbits with multiple loops near the secondary in the Jupiter-Europa system, and their characteristics are explored. Different parameters such as period and stability are examined for each set of resonant orbits, and the continuation of several specific orbits is explored in more detail.

  19. OBSERVATIONS AND ORBITAL ANALYSIS OF THE GIANT WHITE DWARF BINARY SYSTEM HR 5692

    SciTech Connect

    Stefanik, Robert P.; Torres, Guillermo; Latham, David W.; Landsman, Wayne; Craig, Nathaniel; Murrett, James

    2011-05-15

    We report spectroscopic observations of the red giant star HR 5692, previously known to be a binary system both from other spectroscopic work and from deviations in the astrometric motion detected by the Hipparcos satellite. Earlier International Ultraviolet Explorer (IUE) observations had shown the presence of a hot white dwarf companion to the giant primary. We have combined our radial velocity observations with other existing measurements and with the Hipparcos intermediate astrometric data to determine a complete astrometric-spectroscopic orbital solution, providing the inclination angle for the first time. We also determine an improved parallax for the system of 10.12 {+-} 0.67 mas. We derive the physical properties of the primary, and with an estimate of its mass from stellar evolution models (1.84 {+-} 0.40 M{sub sun}), we infer the mass of the white dwarf companion to be M{sub WD} = 0.59 {+-} 0.12 M{sub sun}. An analysis of an IUE white dwarf spectrum, using our parallax, yields T{sub eff} = 30, 400 {+-} 780 K, log g = 8.25 {+-} 0.15, and a mass M{sub WD} = 0.79 {+-} 0.09 M{sub sun}, in marginal agreement with the dynamical mass.

  20. Kepler-432 b: a massive planet in a highly eccentric orbit transiting a red giant

    NASA Astrophysics Data System (ADS)

    Ciceri, S.; Lillo-Box, J.; Southworth, J.; Mancini, L.; Henning, Th.; Barrado, D.

    2015-01-01

    We report the first disclosure of the planetary nature of Kepler-432 b (aka Kepler object of interest KOI-1299.01). We accurately constrained its mass and eccentricity by high-precision radial velocity measurements obtained with the CAFE spectrograph at the CAHA 2.2-m telescope. By simultaneously fitting these new data and Kepler photometry, we found that Kepler-432 b is a dense transiting exoplanet with a mass of Mp = 4.87 ± 0.48MJup and radius of Rp = 1.120 ± 0.036RJup. The planet revolves every 52.5 d around a K giant star that ascends the red giant branch, and it moves on a highly eccentric orbit with e = 0.535 ± 0.030. By analysing two near-IR high-resolution images, we found that a star is located at 1.1'' from Kepler-432, but it is too faint to cause significant effects on the transit depth. Together with Kepler-56 and Kepler-91, Kepler-432 occupies an almost-desert region of parameter space, which is important for constraining the evolutionary processes of planetary systems. RV data (Table A.1) are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/573/L5

  1. Giant Optical Polarization Rotation Induced by Spin-Orbit Coupling in Polarons

    NASA Astrophysics Data System (ADS)

    Casals, Blai; Cichelero, Rafael; García Fernández, Pablo; Junquera, Javier; Pesquera, David; Campoy-Quiles, Mariano; Infante, Ingrid C.; Sánchez, Florencio; Fontcuberta, Josep; Herranz, Gervasi

    2016-07-01

    We have uncovered a giant gyrotropic magneto-optical response for doped ferromagnetic manganite La2 /3Ca1 /3MnO3 around the near room-temperature paramagnetic-to-ferromagnetic transition. At odds with current wisdom, where this response is usually assumed to be fundamentally fixed by the electronic band structure, we point to the presence of small polarons as the driving force for this unexpected phenomenon. We explain the observed properties by the intricate interplay of mobility, Jahn-Teller effect, and spin-orbit coupling of small polarons. As magnetic polarons are ubiquitously inherent to many strongly correlated systems, our results provide an original, general pathway towards the generation of magnetic-responsive gigantic gyrotropic responses that may open novel avenues for magnetoelectric coupling beyond the conventional modulation of magnetization.

  2. Giant cell myocarditis: a life-threatening disorder heralded by orbital myositis.

    PubMed

    Ali, Muhammad Sajawal; Mba, Benjamin I; Husain, Aliya Noor; Ciftci, Farah Diba

    2016-01-01

    A 40-year-old man with a history of orbital myositis (OM) presented to the emergency department with ventricular tachycardia requiring electrical cardioversion. Postcardioversion ECG showed right bundle branch block, while an echocardiogram revealed an ejection fraction of 20% and a dilated right ventricle. Cardiac MRI produced suboptimal images because the patient was having frequent arrhythmias. The rest of the work up, including coronary angiography, was unremarkable. Given the dilated right ventricle, we suspected arrhythmogenic right ventricular cardiomyopathy and discharged the patient with an implantable cardioverter-defibrillator. 1 week later, he was readmitted with cardiogenic shock; endomyocardial biopsy revealed giant cell myocarditis (GCM). To the best of our knowledge, this is the seventh case report of GCM described in a patient with OM. We recommend that clinicians maintain a high degree of suspicion for GCM in patients with OM presenting with cardiac problems. PMID:27009192

  3. Comparative orbital evolution of transient Uranian co-orbitals: exploring the role of ephemeral multibody mean motion resonances

    NASA Astrophysics Data System (ADS)

    de la Fuente Marcos, C.; de la Fuente Marcos, R.

    2014-07-01

    Uranus has three known co-orbitals: 83982 Crantor (2002 GO9), 2010 EU65 and 2011 QF99. All of them were captured in their current resonant state relatively recently. Here, we perform a comparative analysis of the orbital evolution of these transient co-orbitals to understand better how they got captured in the first place and what makes them dynamically unstable. We also look for additional temporary Uranian co-orbital candidates among known objects. Our N-body simulations show that the long-term stability of 2011 QF99 is controlled by Jupiter and Neptune; it briefly enters the 1:7 mean motion resonance with Jupiter and the 2:1 with Neptune before becoming a Trojan and prior to leaving its tadpole orbit. During these ephemeral two-body mean motion resonance episodes, apsidal corotation resonances are also observed. For known co-orbitals, Saturn is the current source of the main destabilizing force but this is not enough to eject a minor body from the 1:1 commensurability with Uranus. These objects must enter mean motion resonances with Jupiter and Neptune in order to be captured or become passing Centaurs. Asteroid 2010 EU65, a probable visitor from the Oort cloud, may have been stable for several Myr due to its comparatively low eccentricity. Additionally, we propose 2002 VG131 as the first transient quasi-satellite candidate of Uranus. Asteroid 1999 HD12 may signal the edge of Uranus' co-orbital region. Transient Uranian co-orbitals are often submitted to complex multibody ephemeral mean motion resonances that trigger the switching between resonant co-orbital states, making them dynamically unstable. In addition, we show that the orbital properties and discovery circumstances of known objects can be used to outline a practical strategy by which additional Uranus' co-orbitals may be found.

  4. THE ANGLO-AUSTRALIAN PLANET SEARCH. XXI. A GAS-GIANT PLANET IN A ONE YEAR ORBIT AND THE HABITABILITY OF GAS-GIANT SATELLITES

    SciTech Connect

    Tinney, C. G.; Wittenmyer, Robert A.; Bailey, Jeremy A.; Horner, J.; Butler, R. Paul; Jones, Hugh R. A.; O'Toole, Simon J.; Carter, Brad D.

    2011-05-01

    We have detected the Doppler signature of a gas-giant exoplanet orbiting the star HD 38283, in an eccentric orbit with a period of almost exactly one year (P = 363.2 {+-} 1.6 d, m sin i = 0.34 {+-} 0.02 M{sub Jup}, e = 0.41 {+-} 0.16). The detection of a planet with period very close to one year critically relied on year-round observation of this circumpolar star. Discovering a planet in a 1 AU orbit around a G dwarf star has prompted us to look more closely at the question of the habitability of the satellites of such planets. Regular satellites orbit all the giant planets in our solar system, suggesting that their formation is a natural by-product of the planet formation process. There is no reason for exomoon formation not to be similarly likely in exoplanetary systems. Moreover, our current understanding of that formation process does not preclude satellite formation in systems where gas giants undergo migration from their formation locations into the terrestrial planet habitable zone. Indeed, regular satellite formation and Type II migration are both linked to the clearing of a gap in the protoplanetary disk by a planet, and so may be inextricably linked. Migration would also multiply the chances of capturing both irregular satellites and Trojan companions sufficiently massive to be habitable. The habitability of such exomoons and exo-Trojans will critically depend on their mass, whether or not they host a magnetosphere, and (for the exomoon case) their orbital radius around the host exoplanet.

  5. Giant Rashba spin-orbit splitting in n - p codoped graphene

    NASA Astrophysics Data System (ADS)

    Qi, Shifei; Yang, Yingping; Qiao, Zhenhua; Xu, Xiaohong; Institute of Materials Chemistry Team; ICQD Team

    Enhancement of the spin-orbit coupling (SOC) in graphene may lead to various topological phenomena and also find applications in spintronics. However, increasing the SOC strength in graphene without drastically affecting the basic physical properties is proving extremely difficult. Here, we propose a new approach, based on compensated n - - p codoping, that can simultaneously address all the main shortcomings associated with single-element adsorption in graphene, effectively resulting in giant Rashba spin-orbit splitting. Our proposal is to deposit strong SOC adatoms with outer shell p electrons, acting as n-type dopants, onto already p-doped (e.g., by B) graphene. We found that: (1) the electrostatic attraction between the n- and p-type dopants effectively enhances the adsorption of the metal adatoms and suppress their undesirable clustering, (2) considerable (~130 meV) Rashba-type SO splitting can be achieved in the graphene π bands, (3) the charge compensated nature and mutually screening each other of the n - - p codopants helps to preserve the Dirac nature of the charge carriers, and (4) the B doping effect together with intrinsic induced SOC by adatom also lead the codoped system open about 20 ~90 meV band gap. NSFC 11104173, 61434002 and 51025101.

  6. Superconducting quantum spin-Hall systems with giant orbital g-factors

    NASA Astrophysics Data System (ADS)

    Hankiewicz, Ewelina; Reinthaler, Rolf; Tkachov, Grigory

    Topological aspects of superconductivity in quantum spin-Hall systems (QSHSs) such as thin layers of three-dimensional topological insulators (3D Tis) or two-dimensional Tis are in the focus of current research. Here, we describe a novel superconducting quantum spin-Hall effect (quantum spin Hall system in the proximity to the s-wave superconductor and in the orbital in-plane magnetic field), which is protected against elastic backscattering by combined time-reversal and particle-hole symmetry. This effect is characterized by spin-polarized edge states, which can be manipulated in weak magnetic fields due to a giant effective orbital g-factor, allowing the generation of spin currents. The phenomenon provides a novel solution to the outstanding challenge of detecting the spin-polarization of the edge states. Here we propose the detection of the edge polarization in the three-terminal junction using unusual transport properties of superconducting quantum Hall-effect: a non-monotonic excess current and a zero-bias conductance splitting. We thank for the financial support the German Science Foundation (DFG), Grants No HA 5893/4-1 within SPP 1666, HA5893/5-2 within FOR1162 and TK60/1-1 (G.T.), as well the ENB graduate school ``Topological insulators''.

  7. Magnetic resonance imaging findings in giant cell arteritis.

    PubMed

    D'Souza, N M; Morgan, M L; Almarzouqi, S J; Lee, A G

    2016-05-01

    PurposeGiant cell arteritis (GCA) is a systemic vasculitis that affects medium-to-large-caliber arteries. Early diagnosis and treatment is essential as involvement of the ophthalmic artery or its branches may cause blindness. Radiographic findings may be variable and non-specific leading to delay in diagnosis. We conducted a review of the literature on neuroimaging findings in GCA and present a retrospective case series from tertiary-care ophthalmic referral centers of three patients with significant neuroimaging findings in biopsy-proven GCA.MethodsRetrospective case series of biopsy-proven GCA cases with neuroimaging findings at the Department of Ophthalmology, Blanton Eye Institute, Houston Methodist Hospital between 2010-2015 were included in this study. Literature search was conducted using Google Scholar and Medline search engines between the years 1970 and 2015.ResultsWe report findings of optic nerve enhancement, optic nerve sheath enhancement, and the first description in the English-language ophthalmic literature, to our knowledge, of chiasmal enhancement in biopsy-proven GCA. We describe four main categories of neuroimaging findings that may be seen in GCA from our series and from past cases in the literature.DiscussionIt is essential that clinicians be aware of the possible radiographic findings in GCA. Appropriate and prompt treatment should not be delayed based upon these findings. PMID:26915748

  8. INTERACTION OF A GIANT PLANET IN AN INCLINED ORBIT WITH A CIRCUMSTELLAR DISK

    SciTech Connect

    Marzari, F.; Nelson, Andrew F. E-mail: andy.nelson@lanl.go

    2009-11-10

    We investigate the dynamical evolution of a Jovian-mass planet injected into an orbit highly inclined with respect to its nesting gaseous disk. Planet-planet scattering induced by convergent planetary migration and mean motion resonances may push a planet into such an out-of-plane configuration with inclinations as large as 20{sup 0}-30{sup 0}. In this scenario, the tidal interaction of the planet with the disk is more complex and, in addition to the usual Lindblad and corotation resonances, it also involves inclination resonances responsible for bending waves. We have performed three-dimensional hydrodynamic simulations of the disk and of its interactions with the planet with a smoothed particle hydrodynamics code. A main result is that the initial large eccentricity and inclination of the planetary orbit are rapidly damped on a timescale of the order of 10{sup 3} yr, almost independently of the initial semimajor axis and eccentricity of the planet. The disk is warped in response to the planet perturbations and it precesses. Inward migration also occurs when the planet is inclined, and it has a drift rate that is intermediate between type I and type II migration. The planet is not able to open a gap until its inclination becomes lower than approx10{sup 0}, when it also begins to accrete a significant amount of mass from the disk.

  9. Simplest photonuclear reactions accompanied by the excitation of isovector giant dipole and quadrupole resonances: Semimicroscopic description

    SciTech Connect

    Tulupov, B. A.; Urin, M. H.

    2012-09-15

    A semimicroscopic approach based on the continuum version of the random-phase approximation (CRPA) and on a semiphenomenological inclusion of the fragmentation effect is applied to describing cross sections for photoabsorption and direct plus semidirect and inverse reactions accompanied by the excitation of isovector giant dipole and quadrupole resonances. In addition to the spinless part of the Landau-Migdal interaction and a partly self-consistent phenomenological mean field of the nucleus, that version of the approach which is used here takes into account isovector separable velocity-dependent forces, as well as the effect of the fragmentation shift of the giant-resonance energy. The results obtained by calculating various features of the aforementioned cross sections for a number of magic and semimagic medium-mass nuclei are compared with respective experimental data.

  10. Giant resonance tuning of micro and nanomechanical oscillators

    PubMed Central

    Vitorino, Miguel V.; Carpentier, Simon; Panzarella, Alain; Rodrigues, Mario S.; Costa, Luca

    2015-01-01

    We present a method to tune the resonance frequency and the Q-factor of micro and nano-metric mechanical oscillators. A counteracting loop drives a capacitive force applied to the oscillator. The proportional and differential gains are used to shift the resonance frequency up to 75% and to tune the Q-factor of the oscillator, by changing its effective stiffness and damping ratio. The oscillator position is monitored in a large bandwidth with a fiber-optic based interferometer. We applied this simple operational scheme with different oscillators for modifying easily their dynamical properties. Compared to alternative methods requiring external fields, our method can either increase or decrease the resonance frequency in a frequency range much more extended. This opens up a wide range of applications, from force sensors with extremely low elastic constants but high quality factor to tunable energy harvesters or to high-frequency tuning of radio frequency filters. The control scheme can work in different media, and is then suitable to be applied to biological sensors and actuators. PMID:25588846

  11. Investigating the Orbital Period Valley of Giant Planets in Kepler Data

    NASA Astrophysics Data System (ADS)

    Thomas, Brianna P.; Birkby, Jayne L.

    2016-01-01

    Transit light curves contain a wealth of information about the basic properties of a planet, such as its radius, semi-major axis, and orbital period. For the latter property, there is a distinct lack of planets with periods between 10 to 100 days. This gap could be caused by something as simple as observational bias, or as prominent as planetary formation or migration. Here, we report an investigation into the atmosphere of planets within this orbital period valley, to search for differences that may indicate a different formation mechanism or migration path to those outside of it. We do this by searching for the secondary eclipse of planets in the valley in order to measure their albedos. We determined an optimal target for this: KOI-366 b (P ~ 75 days). However, we find that despite the exquisite precision of Kepler data, it cannot constrain the albedo for this long-orbit planet candidate. We measure a 1σ upper limit on the geometric albedo of Ag,1σ ≤ 2.0. We highlight that additional scatter in the light curve is likely caused by a ~ 2-day pulsation of the giant host star, and that further data is required to measure the secondary eclipse. KOI-366 is one of the best suited of all host stars with long period exoplanet candidates for follow-up due to its relatively bright magnitude (Kp = 11.7 mag), but the full investigation of the reflective properties of long period planets may require space-based observations from future instruments, such as WFIRST, that will be more sensitive to objects further away from their host stars. This work was supported in part by the NSF REU and DoD ASSURE programs under NSF grant no. 1262851 and by the Smithsonian Institution. This work was performed in part under contract with the Jet Propulsion Laboratory (JPL) funded by NASA through the Sagan Fellowship Program executed by the NASA Exoplanet Science Institute.

  12. Fluxes and spectra of quasimonochromatic annihilation photons for studying E1 giant resonances in nuclei

    SciTech Connect

    Dzhilavyan, L. Z.

    2014-12-15

    The fluxes and spectra of quasimonochromatic photons originating from the in-flight annihilation of positrons interacting with electrons of targets are analyzed in the energy region characteristic of the excitation of E1 giant resonances in nuclei. Targets of small thickness and low atomic number are used. The dependences of the spectra on the energy and angle (and their scatter) for positrons incident to the target, on the collimation angle for photons, and on the target thickness are studied.

  13. Local nuclear magnetic resonance spectroscopy with giant magnetic resistance-based sensors

    NASA Astrophysics Data System (ADS)

    Guitard, P. A.; Ayde, R.; Jasmin-Lebras, G.; Caruso, L.; Pannetier-Lecoeur, M.; Fermon, C.

    2016-05-01

    Nuclear Magnetic Resonance (NMR) spectroscopy on small volumes, either on microfluidic channels or in vivo configuration, is a present challenge. We report here a high resolution NMR spectroscopy on micron scale performed with Giant Magnetic Resistance-based sensors placed in a static magnetic B 0 field of 0.3 T. The sensing volume of the order of several tens of pL opens the way to high resolution spectroscopy on volumes unreached so far.

  14. Recent results on giant dipole resonance decays in highly excited nuclei

    SciTech Connect

    Snover, K.A.

    1991-12-31

    Some recent results on Giant Dipole Resonance (GDR) decays in highly excited, equilibrated nuclei, are discussed based primarily on work done at Seattle. Four sections address the following topics: oblate shapes of rotating, highly excited Zr--Mo nuclei; adiabatic versus `motionally narrowed` GDR decay; large spin-driven deformations observed in hot medium-mass nuclei; and search for entrance channel effects in GDR decay following {sup 58}Ni {plus} {sup 92}Zr fusion. 22 refs.

  15. Recent results on giant dipole resonance decays in highly excited nuclei

    SciTech Connect

    Snover, K.A.

    1991-01-01

    Some recent results on Giant Dipole Resonance (GDR) decays in highly excited, equilibrated nuclei, are discussed based primarily on work done at Seattle. Four sections address the following topics: oblate shapes of rotating, highly excited Zr--Mo nuclei; adiabatic versus motionally narrowed' GDR decay; large spin-driven deformations observed in hot medium-mass nuclei; and search for entrance channel effects in GDR decay following [sup 58]Ni [plus] [sup 92]Zr fusion. 22 refs.

  16. EUV-driven ionospheres and electron transport on extrasolar giant planets orbiting active stars

    NASA Astrophysics Data System (ADS)

    Chadney, J. M.; Galand, M.; Koskinen, T. T.; Miller, S.; Sanz-Forcada, J.; Unruh, Y. C.; Yelle, R. V.

    2016-03-01

    The composition and structure of the upper atmospheres of extrasolar giant planets (EGPs) are affected by the high-energy spectrum of their host stars from soft X-rays to the extreme ultraviolet (EUV). This emission depends on the activity level of the star, which is primarily determined by its age. In this study, we focus upon EGPs orbiting K- and M-dwarf stars of different ages - ɛ Eridani, AD Leonis, AU Microscopii - and the Sun. X-ray and EUV (XUV) spectra for these stars are constructed using a coronal model. These spectra are used to drive both a thermospheric model and an ionospheric model, providing densities of neutral and ion species. Ionisation - as a result of stellar radiation deposition - is included through photo-ionisation and electron-impact processes. The former is calculated by solving the Lambert-Beer law, while the latter is calculated from a supra-thermal electron transport model. We find that EGP ionospheres at all orbital distances considered (0.1-1 AU) and around all stars selected are dominated by the long-lived H+ ion. In addition, planets with upper atmospheres where H2 is not substantially dissociated (at large orbital distances) have a layer in which H3+ is the major ion at the base of the ionosphere. For fast-rotating planets, densities of short-lived H3+ undergo significant diurnal variations, with the maximum value being driven by the stellar X-ray flux. In contrast, densities of longer-lived H+ show very little day/night variability and the magnitude is driven by the level of stellar EUV flux. The H3+ peak in EGPs with upper atmospheres where H2 is dissociated (orbiting close to their star) under strong stellar illumination is pushed to altitudes below the homopause, where this ion is likely to be destroyed through reactions with heavy species (e.g. hydrocarbons, water). The inclusion of secondary ionisation processes produces significantly enhanced ion and electron densities at altitudes below the main EUV ionisation peak, as

  17. Isoscalar giant resonance studies in a stored-beam experiment within EXL

    NASA Astrophysics Data System (ADS)

    Zamora, J. C.; Bagchi, S.; Bönig, S.; Csatlós, M.; Dillmann, I.; Dimopoulou, C.; Egelhof, P.; Eremin, V.; Furuno, T.; Geissel, H.; Gernhäuser, R.; Harakeh, M. N.; Hartig, A.-L.; Ilieva, S.; Kalantar-Nayestanaki, N.; Kiselev, O.; Kollmus, K.; Kozhuharov, C.; Krasznahorkay, A.; Kröll, T.; Kuilman, M.; Litvinov, S.; Litvinov, Yu A.; Mahjour-Shafiei, M.; Mutterer, M.; Nagae, D.; Najafi, M. A.; Nociforo, C.; Nolden, F.; Popp, U.; Rigollet, C.; Roy, S.; Scheidenberger, C.; von Schmid, M.; Steck, M.; Streicher, B.; Stuhl, L.; Thürauf, M.; Uesaka, T.; Weick, H.; Winfield, J. S.; Winters, D.; Woods, P. J.; Yamaguchi, T.; Yue, K.; Zenihiro, J.; the EXL Collaboration

    2015-11-01

    In the first campaign of the exotic nuclei studied with light-ion induced reaction in storage rings (EXL) collaboration at the existing storage ring experimental heavy-ion storage ring (ESR) at Helmholtz Center for Heavy Ion Research (GSI), we performed the first experiments using a stored beam of 58Ni and an internal helium gas-jet target aiming for the investigation of isoscalar giant resonances in inverse kinematics. In this experiment, inelastically scattered recoil particles (at very forward angles, {θ }{cm}≤slant 1°) were detected with a dedicated setup, including ultra-high vacuum (UHV)-compatible double-sided silicon strip detector (DSSDs). Preliminary results show evidence for the excitation of the isoscalar giant monopole resonance (ISGMR) in the 58Ni nucleus. This opens the opportunity to study in the near future giant resonances also with stored radioactive beams, like 56Ni, and extract important information about the nuclear matter incompressibility. In the present work the current status of the data analysis and results are shown and discussed.

  18. Giant Resonances in the Alpha-Nucleus Interaction

    SciTech Connect

    Karpeshin, F. F.

    2010-04-30

    Tunneling of alpha particles through the Coulomb barrier for the source {sup 135}Pr nucleus is consecutively considered. The effect of sharp peaks arising in the case of coincidence of the alpha energy with that of a quasistationary state within the barrier is elucidated. Peaks' energy depend on the alpha-nucleus potential. They can give rise to 'anomalous' properties of some neutron resonances. The peaks can also be observed in the incoming alpha-nucleus channel. The method can be applied for solution of the reverse problem of the alpha-nucleus scattering.

  19. Argand diagram representation of orbiting resonance in proton-transfer collision

    NASA Astrophysics Data System (ADS)

    Lutrus, C. K.; Suck Salk, S. H.

    1991-05-01

    Dynamic resonance in atom-diatomic molecule collisions has been relatively well studied compared to orbiting resonance. We discuss orbiting resonance on reactive scattering involving proton (charge) transfer. Resonance structure is predicted to exist at forward-scattering angles in both the state-to-state angular distribution and the Argand diagram for the proton-transfer collision system of He+H+2-->HeH++H. The present study demonstrates the possibility of orbiting resonance particularly in proton (charge) -transfer reaction involving atom-diatomic molecule systems.

  20. Earth-orbiting resonant-mass gravitational wave detectors

    NASA Technical Reports Server (NTRS)

    Paik, Ho Jung

    1989-01-01

    Earth-based gravitational wave detectors suffer from the need to support the large antenna masses against the earth's gravity without transmitting a significant amount of seismic noise. Passive vibration isolation is difficult to achieve below 1 Hz on the earth. Vibration-free space environment thus gives an opportunity to extend the frequency window of gravitational wave detection to ultralow frequencies. The weightless condition of a space laboratory also enables construction of a highly symmetric multimode antenna which is capable of resolving the direction of the source and the polarization of the incoming wave without resorting to multiantenna coincidence. Two types of earth-orbiting resonant-mass gravitational wave detectors are considered. One is a skyhook gravitational wave detector, proposed by Braginsky and Thorne (1985). The other is a spherical detector, proposed by Forward (1971) and analyzed by Wagoner and Paik (1976).

  1. Spacecraft transfer trajectory design exploiting resonant orbits in multi-body environments

    NASA Astrophysics Data System (ADS)

    Vaquero Escribano, Tatiana Mar

    Historically, resonant orbits have been employed in mission design for multiple planetary flyby trajectories and, more recently, as a source of long-term orbital stability. For instance, in support of a mission concept in NASA's Outer Planets Program, the Jupiter Europa Orbiter spacecraft is designed to encounter two different resonances with Europa during the 'endgame' phase, leading to Europa orbit insertion on the final pass. In 2011, the Interstellar Boundary Explorer spacecraft was inserted into a stable out-of-plane lunar-resonant orbit, the first of this type for a spacecraft in a long-term Earth orbit. However, resonant orbits have not yet been significantly explored as transfer mechanisms between non-resonant orbits in multi-body systems. This research effort focuses on incorporating resonant orbits into the design process to potentially enable the construction of more efficient or even novel transfer scenarios. Thus, the goals in this investigation are twofold: i) to expand the orbit architecture in multi-body environments by cataloging families of resonant orbits, and ii) to assess the role of such families in the design of transfer trajectories with specific patterns and itineraries. The benefits and advantages of employing resonant orbits in the design process are demonstrated through a variety of astrodynamics applications in several multi-body systems. In the Earth-Moon system, locally optimal transfer trajectories from low Earth orbit to selected libration point orbits are designed by leveraging conic arcs and invariant manifolds associated with resonant orbits. Resonant manifolds in the Earth-Moon system offer trajectories that tour the entire space within reasonable time intervals, facilitating the design of libration point orbit tours as well as Earth-Moon cyclers. In the Saturnian system, natural transitions between resonant and libration point orbits are sought and the problem of accessing Hyperion from orbits that are resonant with Titan is

  2. Numerical study of the giant nonlocal resistance in spin-orbit coupled graphene

    NASA Astrophysics Data System (ADS)

    Wang, Zibo; Liu, Haiwen; Jiang, Hua; Xie, X. C.

    2016-07-01

    Recent experiments find the signal of giant nonlocal resistance RNL in H -shaped graphene samples due to the spin/valley Hall effect. Interestingly, when the Fermi energy deviates from the Dirac point, RNL decreases to zero much more rapidly compared with the local resistance RL, and the well-known relation of RNL∝RL3 is not satisfied. In this work, based on the nonequilibrium Green's function method, we explain such transport phenomena in H -shaped graphene with Rashba spin-orbit coupling. When the Fermi energy is near the Dirac point, the nonlocal resistance is considerably large and is much sharper than the local one. Moreover, the relationship between the Rashba effect and the fast decay of RNL compared with RL is further investigated. We find that the Rashba effect contributes neither to the fast decay nor to the peak of RNL itself. Actually, it is the extremely small density of states near the Dirac point that leads to the large peak of RNL, while the fast decay results from the quasiballistic mechanism. Finally, we revise the classic formula RNL∝RL3 by replacing RNL with RHall, which represents the nonlocal resistance merely caused by the spin Hall effect, and the relation holds well.

  3. Correlations between Compositions and Orbits Established by the Giant Impact Era of Planet Formation

    NASA Astrophysics Data System (ADS)

    Dawson, Rebekah I.; Lee, Eve J.; Chiang, Eugene

    2016-05-01

    The giant impact phase of terrestrial planet formation establishes connections between super-Earths’ orbital properties (semimajor axis spacings, eccentricities, mutual inclinations) and interior compositions (the presence or absence of gaseous envelopes). Using N-body simulations and analytic arguments, we show that spacings derive not only from eccentricities, but also from inclinations. Flatter systems attain tighter spacings, a consequence of an eccentricity equilibrium between gravitational scatterings, which increase eccentricities, and mergers, which damp them. Dynamical friction by residual disk gas plays a critical role in regulating mergers and in damping inclinations and eccentricities. Systems with moderate gas damping and high solid surface density spawn gas-enveloped super-Earths with tight spacings, small eccentricities, and small inclinations. Systems in which super-Earths coagulate without as much ambient gas, in disks with low solid surface density, produce rocky planets with wider spacings, larger eccentricities, and larger mutual inclinations. A combination of both populations can reproduce the observed distributions of spacings, period ratios, transiting planet multiplicities, and transit duration ratios exhibited by Kepler super-Earths. The two populations, both formed in situ, also help to explain observed trends of eccentricity versus planet size, and bulk density versus method of mass measurement (radial velocities versus transit timing variations). Simplifications made in this study—including the limited time span of the simulations, and the approximate treatments of gas dynamical friction and gas depletion history—should be improved on in future work to enable a detailed quantitative comparison to the observations.

  4. 'Coulomb' description of basic relaxation parameters of isobar analog and charge-exchange giant monopole resonances

    SciTech Connect

    Gorelik, M. L.; Rykovanov, V. S.; Urin, M. G.

    2010-12-15

    Within a semimicroscopic approach, basic relaxation parameters of the isobaric analog resonance and of the charge-exchange giant monopole resonance, which is an overtone of the isobaric analog resonance, are interpreted in terms of the mean Coulomb field of a nucleus. The continuum version of the random-phase approximation, allowance for an approximate isospin conservation in nuclei in an explicit form, and a phenomenological description of the fragmentation effect are basic ingredients of the approach used. The aforementioned parameters were calculated for a number of magic and near-magic nuclei by using a partly self-consistent phenomenological nuclear mean field and the isovector part of the Landau-Migdal interaction in the particle-hole channel. The results of the calculations are compared with corresponding experimental data.

  5. Ring Dynamics at Saturn: Wakes, Resonances, Warps and Orbital Migration

    NASA Astrophysics Data System (ADS)

    Nicholson, Philip D.; Hedman, M. M.; Tiscareno, M. S.; Burns, J. A.; French, R. G.; French, R. G.; Marouf, E. A.; Colwell, J. E.

    2012-01-01

    In addition to their incomparable beauty in a small telescope, the rings of Saturn have long provided astronomers with a nearby laboratory for developing and testing theories of disk dynamics. After seven years of successful operations, the Cassini orbiter has greatly increased our knowledge of this system, and revealed many new and unexpected phenomena. Ring thicknesses of as little as 5-10 meters are inferred from particle velocity dispersions and from the ubiquitous `self-gravity wakes'. The latter are close cousins of the trailing structures seen in simulations of self-gravitating stellar disks in the 1980s. Two of the 15 or so narrow gaps in the rings are maintained by km-size embedded moonlets; the others remain unexplained though several have edges defined by Lindblad resonances with larger, external satellites. Many gap and ringlet edges are noncircular, exhibiting a surprisingly wide range of perturbations which seem to reflect multiple `normal modes' excited within the rings. Images taken near the Saturnian equinox in mid-2009 under conditions of grazing solar illumination reveal a spiral-shaped warp which extends all the way across the C and D rings. Models of this structure strongly suggest that it is due to an impact on the rings of a cloud of interplanetary debris in September 1983, perhaps due to a disrupted comet like Shoemaker-Levy 9. Although even Cassini is unable to image individual ring particles, the highest resolution images of the A ring show intriguing structures known as `propellers' which appear to be the gravitational signature of large embedded objects, perhaps 100 m in size. Long-term tracking of the largest propellers shows clear evidence for non-keplerian motion, possibly akin to the orbital migration predicted for protoplanets embedded in circumstellar disks.

  6. Flyby Design Using Heteroclinic and Homoclinic Connections of Unstable Resonant Orbits

    NASA Technical Reports Server (NTRS)

    Anderson, Rodney L.; Lo, Martin W.

    2011-01-01

    Tour designs using flybys have traditionally been studied using two-body patched conic methods. Previous work has shown that trajectories designed using these techniques and with optimization methods follow the invariant manifolds of unstable resonant orbits as they transition between resonances. This work is continued here by computing heteroclinic and homoclinic trajectories associated with these unstable resonant orbits. These trajectories are used with multiple resonances to design flybys that transition between these resonances in the circular restricted three-body problem without the need for two-body approximations.

  7. Chaos-driven decay of nuclear giant resonances: Quantum route to self-organization

    SciTech Connect

    Drozdz, S.; Nishizaki, S.; Wambach, J. Institute of Nuclear Physics, PL-31-342 Krakow Institut fuer Kernphysik, Forschungszentrum Juelich, D-5170 Juelich College of Humanities and Social Sciences, Iwate University, Ueda 3-18-34, Morioka 020 )

    1994-05-02

    The influence of background states with increasing level of complexity on the strength distribution of the isoscalar and isovector giant quadrupole resonance in [sup 40]Ca is studied. It is found that the background characteristics, typical for chaotic systems, strongly affect the fluctuation properties of the strength distribution. In particular, the small components of the wave function obey a scaling law analogous to self-organized systems at the critical state. This appears to be consistent with the Porter-Thomas distribution of the transition strength.

  8. Fission decay of the giant quadrupole resonance for /sup 234/U

    SciTech Connect

    Arruda-Neto, J.D.T.; Berman, B.L.; Herdade, S.B.; Nascimento, I.C.

    1981-06-01

    The electrofission cross section for /sup 234/U from 5.5 to 25.4 MeV has been measured. From a combined analysis of it and the previously measured photofission cross section, using virtual-photon spectra calculated in the distorted-wave Born approximation, the E2 photofission cross section has been determined. Parameters of the fission-decay branch of the giant quadrupole resonance for this nucleus have been obtained. A comparison of the E2 and E1 integrated photofission cross sections for the even uranium isotopes shows that the E1 fission channel increases in strength more rapidly with fissility than does the E2 channel.

  9. Photofission of {sup 238}U in the giant-resonance region

    SciTech Connect

    Dzhilavyan, L. Z. Nedorezov, V. G.

    2013-12-15

    Data on cross sections for the reaction {sup 238}U(γ,F) in the giant-resonance region were analyzed in connection with the preparation of new experiments aimed at studying {sup 238}U photofission—in particular, in beams of photons from in-flight positron annihilation on internal targets of positron storage rings. These data were taken from measurements also performed with annihilation photons but from positron beams external to the accelerators used. The procedures applied in such measurements and based both on processing the multiplicity of detected neutrons and on detecting fission fragments were also analyzed.

  10. Excitation of giant monopole resonance in {sup 24}Mg using {sup 6}Li scattering

    SciTech Connect

    Dennert, H.; Aschenauer, E.; Eyrich, W.; Lehmann, A.; Moosburger, M.; Scholz, N.; Wirth, H.; Gils, H.J.; Rebel, H.; Zagromski, S.

    1995-12-01

    The isoscalar giant monopole resonance in the nucleus {sup 24}Mg was investigated by inelastic {sup 6}Li scattering at {ital E}{sub Li}=156 MeV. At extreme forward angles fragmented {ital E}0 strength was observed up to {ital E}{sub {ital x}}=23 MeV. The extracted strength centered at 18.3{plus_minus}0.5 MeV excitation energy with a width of {Gamma}=4.8{plus_minus}0.5 MeV corresponds to 97.3%{plus_minus}15% of the {ital E}0 energy weighted sum rule.

  11. The gamma decay of the giant dipole resonance: from zero to finite temperature

    NASA Astrophysics Data System (ADS)

    Bracco, Angela; Camera, Franco

    2016-08-01

    This paper is intended to give a selected and rather brief overview of the work made in the last thirty years to study the properties of the giant dipole resonance focusing in particular on nuclei formed at finite temperatures using heavy ion reactions. The physical problems that are discussed (using examples of particular results) in this paper can be grouped into 3 major topics: (i) the temperature dependence of the GDR width; (ii) the dipole oscillation in reaction dynamics; (iii) the isospin mixing at finite temperature.

  12. Dopamine-secreting giant adrenal ganglioneuroma: clinical and diffusion-weighted magnetic resonance imaging findings.

    PubMed

    Polat, A V; Polat, A Kamali; Aslan, K; Atmaca, H; Karagoz, F

    2014-01-01

    We report a case of a dopamine-secreting giant primary adrenal ganglioneuroma (GN) in a 29-year-old male patient. Although the patient was clinically silent, the 24-hour urine levels of dopamine, normetanephrine, homovanillic acid and vanillyl mandelic acid were elevated. Abdominal ultrasonography and magnetic resonance imaging showed a large solid tumor with calcifications and a slightly lobular edge on the left adrenal gland. A tumor, 13 x 23 x 25 cm in size, was completely resected without morbidity. A 2-year follow-up with computed tomography showed that the postoperative course of the patient was uneventful. PMID:25073244

  13. Capture of planets into mean-motion resonances and the origins of extrasolar orbital architectures

    NASA Astrophysics Data System (ADS)

    Batygin, Konstantin

    2015-08-01

    The early stages of dynamical evolution of planetary systems are often shaped by dissipative processes that drive orbital migration. In multi-planet systems, convergent amassing of orbits inevitably leads to encounters with rational period ratios, which may result in establishment of mean-motion resonances. The success or failure of resonant capture yields exceedingly different subsequent evolutions, and thus plays a central role in determining the ensuing orbital architecture of planetary systems. In this work, we employ an integrable Hamiltonian formalism for first order planetary resonances that allows both secondary bodies to have finite masses and eccentricities, and construct a comprehensive theory for resonant capture. Particularly, we derive conditions under which orbital evolution lies within the adiabatic regime, and provide a generalized criterion for guaranteed resonant locking as well as a procedure for calculating capture probabilities when capture is not certain. Subsequently, we utilize the developed analytical model to examine the evolution of Jupiter and Saturn within the protosolar nebula, and investigate the origins of the dominantly non-resonant orbital distribution of sub-Jovian extrasolar planets. Our calculations show that the commonly observed extrasolar orbital structure can be understood if planet pairs encounter mean-motion commensurabilities on slightly eccentric (e ˜ 0.02) orbits. Accordingly, we speculate that resonant capture among low-mass planets is typically rendered unsuccessful due to subtle axial asymmetries inherent to the global structure of protoplanetary discs.

  14. Broad Search for Unstable Resonant Orbits in the Planar Circular Restricted Three-Body Problem

    NASA Technical Reports Server (NTRS)

    Anderson, Rodney L.; Campagnola, Stefano; Lantoine, Gregory

    2013-01-01

    Unstable resonant orbits in the circular restricted three-body problem have increasingly been used for trajectory design using optimization and invariant manifold techniques.In this study, several methods for computing these unstable resonant orbits are explored including flyby maps, continuation from two-body models, and grid searches. Families of orbits are computed focusing on the Jupiter-Europa system, and their characteristics are explored. Different parameters such as period and stability are examined for each set of resonantor bits, and the continuation of several specific orbits is explored in more detail.

  15. Panel 1: A pulsating red giant star and a compact, hot white dwarf star orbit each other.

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Panel 1: A pulsating red giant star and a compact, hot white dwarf star orbit each other. Panel 2: The red giant sheds much of its outer layers in a stellar wind. The white dwarf helps concentrate the wind along a thin equatorial plane. The white dwarf accretes some of this escaping gas forming a disk around the itself. Panel 3: When enough gas accumulates on the white dwarf's surface it explodes as a nova outburst. Most of the hot gas forms a pair of expanding bubbles above and below the equatorial disk. Panel 4: A few thousand years after the bubbles expand into space, the white dwarf goes through another nova outburst and makes another pair of bubbles, which form a distinctive hourglass shape.

  16. Radial Velocity Observations and Light Curve Noise Modeling Confirm that Kepler-91b is a Giant Planet Orbiting a Giant Star

    NASA Astrophysics Data System (ADS)

    Barclay, Thomas; Endl, Michael; Huber, Daniel; Foreman-Mackey, Daniel; Cochran, William D.; MacQueen, Phillip J.; Rowe, Jason F.; Quintana, Elisa V.

    2015-02-01

    Kepler-91b is a rare example of a transiting hot Jupiter around a red giant star, providing the possibility to study the formation and composition of hot Jupiters under different conditions compared to main-sequence stars. However, the planetary nature of Kepler-91b, which was confirmed using phase-curve variations by Lillo-Box et al., was recently called into question based on a re-analysis of Kepler data. We have obtained ground-based radial velocity observations from the Hobby-Eberly Telescope and unambiguously confirm the planetary nature of Kepler-91b by simultaneously modeling the Kepler and radial velocity data. The star exhibits temporally correlated noise due to stellar granulation which we model as a Gaussian Process. We hypothesize that it is this noise component that led previous studies to suspect Kepler-91b to be a false positive. Our work confirms the conclusions presented by Lillo-Box et al. that Kepler-91b is a 0.73 ± 0.13 M Jup planet orbiting a red giant star. Based partly on observations obtained with the Hobby-Eberly Telescope, which is a joint project of the University of Texas at Austin, the Pennsylvania State University, Stanford University, Ludwig-Maximilians-Universität München, and Georg-August-Universität Göttingen.

  17. RADIAL VELOCITY OBSERVATIONS AND LIGHT CURVE NOISE MODELING CONFIRM THAT KEPLER-91b IS A GIANT PLANET ORBITING A GIANT STAR

    SciTech Connect

    Barclay, Thomas; Huber, Daniel; Rowe, Jason F.; Quintana, Elisa V.; Foreman-Mackey, Daniel

    2015-02-10

    Kepler-91b is a rare example of a transiting hot Jupiter around a red giant star, providing the possibility to study the formation and composition of hot Jupiters under different conditions compared to main-sequence stars. However, the planetary nature of Kepler-91b, which was confirmed using phase-curve variations by Lillo-Box et al., was recently called into question based on a re-analysis of Kepler data. We have obtained ground-based radial velocity observations from the Hobby-Eberly Telescope and unambiguously confirm the planetary nature of Kepler-91b by simultaneously modeling the Kepler and radial velocity data. The star exhibits temporally correlated noise due to stellar granulation which we model as a Gaussian Process. We hypothesize that it is this noise component that led previous studies to suspect Kepler-91b to be a false positive. Our work confirms the conclusions presented by Lillo-Box et al. that Kepler-91b is a 0.73 ± 0.13 M {sub Jup} planet orbiting a red giant star.

  18. Primary orbital hydatid cyst: computed tomography and magnetic resonance imaging findings

    PubMed Central

    Öztekin, Pelin Seher; Yilmaz, Behice Kaniye; Gokharman, Fatma Dilek; Koşar, Pınar Nergis

    2014-01-01

    Orbital hydatid cyst is a rare form of hydatidosis, comprising less than 1% of all hydatid cysts reported. The first choice of treatment for orbital hydatid cyst is surgery. Preoperative diagnosis is important, so as to avoid rupture of the cyst and prevent the spread of the parasitic disease. Herein, we present the computed tomography and magnetic resonance imaging findings of a case of primary orbital hydatid cyst. PMID:25631981

  19. 15th order resonance terms using the decaying orbit of TETR-3. [perturbation due to gravitation

    NASA Technical Reports Server (NTRS)

    Wagner, C. A.; Klosko, S. M.

    1975-01-01

    Fifteenth-order commensurability of the orbit of TETR-3 (1971-83B) is studied. The study is designed to obtain good discrimination of 15th-order resonances through a better range of inclinations. The first low inclination orbit, 33 deg, is used for this purpose; it is very sensitive to the high degree terms which were rather poorly represented by previously analyzed orbits.

  20. A Rare Case of a Recurrent Giant Solitary Fibrous Tumor of the Ciliary Body of the Orbit.

    PubMed

    Krishnamurthy, Arvind; Singh, Shirley Sundar; Majhi, Urmila; Ramshankar, Vijayalakshmi; Krishnamurthy, Arvind

    2016-07-01

    Solitary fibrous tumors (SFTs) are uncommon spindle-cell tumors of mesenchymal origin initially described in the pleura and subsequently in other extra-pleural sites. These tumors are categorized as tumors of 'intermediate malignancy' under the World Health Organization classification of soft tissue tumors. SFT was virtually non-existent or misdiagnosed until its characteristic features, particularly the strong and diffuse immuno-reactivity to CD 34 were described. Extra-pleural manifestations of SFT, particularly in the head and neck region are rare. Although a number of isolated case reports of orbital SFTs have been described ever since its initial description in 1994, cases of recurrent SFTs have been very few. Recurrences of these tumors following surgery are considered unusual and metastasis exceptional. We describe clinical presentation and the management challenges of recurrent giant orbital SFT in a 15-year old girl along with a brief review of literature. PMID:27408474

  1. Formation of giant molecular clouds in global spiral structures: The role of orbital dynamics and cloud-cloud collisions

    NASA Technical Reports Server (NTRS)

    Roberts, W. W., Jr.; Stewart, G. R.

    1987-01-01

    The different roles played by orbital dynamics and dissipative cloud-cloud collisions in the formation of giant molecular clouds (GMCs) in a global spiral structure are investigated. The interstellar medium (ISM) is simulated by a system of particles, representing clouds, which orbit in a spiral-perturbed, galactic gravitational field. The overall magnitude and width of the global cloud density distribution in spiral arms is very similar in the collisional and collisionless simulations. The results suggest that the assumed number density and size distribution of clouds and the details of individual cloud-cloud collisions have relatively little effect on these features. Dissipative cloud-cloud collisions play an important steadying role for the cloud system's global spiral structure. Dissipative cloud-cloud collisions also damp the relative velocity dispersion of clouds in massive associations and thereby aid in the effective assembling of GMC-like complexes.

  2. Orbital and physical parameters of eclipsing binaries from the ASAS catalogue - IX. Spotted pairs with red giants

    NASA Astrophysics Data System (ADS)

    Ratajczak, M.; Hełminiak, K. G.; Konacki, M.; Smith, A. M. S.; Kozłowski, S. K.; Espinoza, N.; Jordán, A.; Brahm, R.; Hempel, M.; Anderson, D. R.; Hellier, C.

    2016-09-01

    We present spectroscopic and photometric solutions for three spotted systems with red giant components. Absolute physical and orbital parameters for these double-lined detached eclipsing binary stars are presented for the first time. These were derived from the V-, and I-band ASAS and WASP photometry, and new radial velocities calculated from high quality optical spectra we obtained with a wide range of spectrographs and using the two-dimensional cross-correlation technique (TODCOR). All of the investigated systems (ASAS J184949-1518.7, BQ Aqr, and V1207 Cen) show the differential evolutionary phase of their components consisting of a main-sequence star or a subgiant and a red giant, and thus constitute very informative objects in terms of testing stellar evolution models. Additionally, the systems show significant chromospheric activity of both components. They can be also classified as classical RS CVn-type stars. Besides the standard analysis of radial velocities and photometry, we applied spectral disentangling to obtain separate spectra for both components of each analysed system which allowed for a more detailed spectroscopic study. We also compared the properties of red giant stars in binaries that show spots, with those that do not, and found that the activity phenomenon is substantially suppressed for stars with Rossby number higher than ˜1 and radii larger than ˜20 R⊙.

  3. Plasmonic coupled modes in metal-dielectric multilayer structures: Fano resonance and giant field enhancement.

    PubMed

    Sekkat, Zouheir; Hayashi, Shinji; Nesterenko, Dmitry V; Rahmouni, Anouar; Refki, Siham; Ishitobi, Hidekazu; Inouye, Yasushi; Kawata, Satoshi

    2016-09-01

    We provide an overview of Fano resonance and plasmon induced transparency (PIT) as well as on plasmons coupling in planar structures, and we discuss their application in sensing and enhanced spectroscopy. Metal-insulator-metal (MIM) structures, which are known to support symmetric and anti-symmetric surface plasmon polaritons (SPPs) arising from the coupling between two SPPs at the metal-insulator interfaces, exhibit anticrossing behavior of the dispersion relations arising from the coupling of the symmetric SPP and the metal/air SPP. Multilayer structures, formed by a metal film and a high-index dielectric waveguide (WG), separated by a low-index dielectric spacer layer, give narrow resonances of PIT and Fano line shapes. An optimized Fano structure shows a giant field intensity enhancement value of 106 in air at the surface of the high-index dielectric WG. The calculated field enhancement factor and the figure of merit for the sensitivity of the Fano structure in air can be 104 times as large as those of the conventional surface plasmon resonance and WG sensors. PMID:27607617

  4. Fluctuation properties of the strength function associated with the giant quadrupole resonance in {sup 208}Pb

    SciTech Connect

    Aiba, Hirokazu; Matsuo, Masayuki; Nishizaki, Shigeru; Suzuki, Toru

    2011-02-15

    We performed fluctuation analysis by means of the local scaling dimension for the strength function of the isoscalar (IS) giant quadrupole resonance (GQR) in {sup 208}Pb where the strength function is obtained by the shell model calculation including 1p1h and 2p2h configurations. It is found that at almost all energy scales, fluctuation of the strength function obeys the Gaussian orthogonal ensemble (GOE) random matrix theory limit. This is contrasted with the results for the GQR in {sup 40}Ca, where at the intermediate energy scale of about 1.7 MeV, a deviation from the GOE limit was detected. It is found that the physical origin for this different behavior of the local scaling dimension is ascribed to the difference in the properties of the damping process.

  5. Fine structure of the isoscalar giant quadrupole resonance in 28Si and 27Al

    NASA Astrophysics Data System (ADS)

    Usman, I. T.; Buthelezi, Z.; Carter, J.; Cooper, G. R. J.; Fearick, R. W.; Förtsch, S. V.; Fujita, H.; Fujita, Y.; von Neumann-Cosel, P.; Neveling, R.; Papakonstantinou, P.; Pysmenetska, I.; Richter, A.; Roth, R.; Sideras-Haddad, E.; Smit, F. D.

    2016-08-01

    The isoscalar giant quadrupole resonance in 28Si and 27Al has been investigated with high-energy-resolution proton inelastic scattering at Ep=200 MeV and at scattering angles close to the maximum of Δ L =2 angular distributions with the K600 magnetic spectrometer of iThemba LABS, South Africa. Characteristic scales are extracted from the observed fine structure with a wavelet analysis and compared for 28Si with random-phase approximation and second random phase approximation calculations with an interaction derived from the Argonne V18 potential by a unitary transformation. A recent extension of the method to deformed nuclei provides the best description of the data, suggesting the significance of Landau damping.

  6. Integrated cross sections for excitation of nuclear isomers by inelastic photon scattering at giant resonance

    NASA Astrophysics Data System (ADS)

    Sáfár, József; Lakosi, László

    2014-02-01

    In the view of the evidences arising from our experimental and theoretical studies, the long-standing picture of a two-humped excitation function for photoexcitation of isomers cannot be confirmed. Whereas the first maximum (at the photoneutron threshold) of the cross section of nuclear photon scattering can be attributed to inelastic (compound) scattering, the second large peak at about giant dipole resonance is mostly due to the elastic (direct) process. A second large peak or increase reported to appear in isomer production has been shown to be practically vanishing. On realizing such a situation, calculated estimates have been given for saturated integral cross section values for isomer activation, based on photoabsorption cross sections taken from the usual Lorentzian parametrization up to the photoneutron threshold. Results compare reasonably well to available experimental data acquired by gamma-ray spectrometry in a large set of stable nuclides having long-lived isomeric states.

  7. Shear-viscosity to entropy-density ratio from giant dipole resonances in hot nuclei

    SciTech Connect

    Nguyen Dinh Dang

    2011-09-15

    The Green-Kubo relation and fluctuation-dissipation theorem are employed to calculate the shear viscosity {eta} of a finite hot nucleus directly from the width and energy of the giant dipole resonance (GDR) of this nucleus. The ratio {eta}/s of shear viscosity {eta} to entropy density s is extracted from the experimental systematics of the GDR in copper, tin, and lead isotopes at finite temperature T. These empirical results are then compared with the predictions by several independent models as well as with almost model-independent estimations. Based on these results, it is concluded that the ratio {eta}/s in medium and heavy nuclei decreases with increasing temperature T to reach (1.3--4)x({h_bar}/2{pi})/(4{pi}k{sub B}) at T=5 MeV.

  8. Neutron-skin thickness from the study of the anti-analog giant dipole resonance

    SciTech Connect

    Krasznahorkay, A.; Stuhl, L.; Csatlos, M.; Algora, A.; and others

    2012-10-20

    The {gamma}-decay of the anti-analog of the giant dipole resonance (AGDR) to the isobaric analog state has been measured following the p({sup 124}Sn,n) reaction at a beam energy of 600 MeV/nucleon. The energy of the transition was also calculated with state-of-the-art self-consistent relativistic random-phase approximation (RPA) and turned out to be very sensitive to the neutronskin thickness ({Delta}R{sub pn}). By comparing the theoretical results with the measured one, the {Delta}R{sub pn} value for {sup 124}Sn was deduced to be 0.21 {+-} 0.07 fm, which agrees well with the previous results. The present method offers new possibilities for measuring the neutron-skin thicknesses of very exotic isotopes.

  9. Measurement of giant dipole resonance width at low temperature: A new experimental perspective

    NASA Astrophysics Data System (ADS)

    Mukhopadhyay, S.; Pandit, Deepak; Pal, Surajit; Bhattacharya, Srijit; De, A.; Bhattacharya, S.; Bhattacharya, C.; Banerjee, K.; Kundu, S.; Rana, T. K.; Mukherjee, G.; Pandey, R.; Gohil, M.; Pai, H.; Meena, J. K.; Banerjee, S. R.

    2012-03-01

    The systematic evolution of the giant dipole resonance (GDR) width in the temperature region of 0.9- 1.4 MeV has been measured experimentally for 119Sb using alpha induced fusion reaction and employing the LAMBDA high energy photon spectrometer. The temperatures have been precisely determined by simultaneously extracting the vital level density parameter from the neutron evaporation spectrum and the angular momentum from gamma multiplicity filter using a realistic approach. The systematic trend of the data seems to disagree with the thermal shape fluctuation model (TSFM). The model predicts the gradual increase of GDR width from its ground state value whereas the measured GDR widths appear to remain constant at the ground state value till T ∼ 1 MeV and increase thereafter, indicating towards a failure of the adiabatic assumption of the model at low temperature.

  10. Are there nuclear structure effects on the isoscalar giant monopole resonance near A = 90?

    NASA Astrophysics Data System (ADS)

    Gupta, Yogesh; Garg, Umesh; Howard, K.; Senyigit, M.; Itoh, M.; Ando, S.; Uchiyama, A.; Aoki, T.; Iwamoto, C.; Adachi, S.; Tamii, A.; Fujiwara, M.; Kadono, C.; Akimune, H.; Matsuda, Y.; Nakahara, T.; Kawabata, T.; Tsumura, M.; Furuno, T.; Harakeh, M.; Kalantar-Nayestanaki, N.

    2015-10-01

    The excitation energy of the isoscalar giant monopole resonance (ISGMR) exhibits, in general, a very smooth behavior (Ex ~A 1 / 3) over the periodic Table. In recent work the Texas A&M group has reported that ISGMR energies for 92Zr and 92Mo are appreciably higher than that for 90Zr, suggesting significant nuclear structure effects on ISGMR and, hence, on the nuclear compressibility. We have measured inelastic scattering of 385-MeV a particles on 90,92Zr, 92Mo at extremely forward angles, including 0°, using the ``Grand Raiden'' spectrometer at RCNP, Japan. Results of detailed multipole decomposition analyses to extract the ISGMR strength distributions in the three nuclei will be presented. Supported in part by the National Science Foundation (Grant No. PHY1419765).

  11. The science case for an orbital mission to Uranus: Exploring the origins and evolution of ice giant planets

    NASA Astrophysics Data System (ADS)

    Arridge, C. S.; Achilleos, N.; Agarwal, J.; Agnor, C. B.; Ambrosi, R.; André, N.; Badman, S. V.; Baines, K.; Banfield, D.; Barthélémy, M.; Bisi, M. M.; Blum, J.; Bocanegra-Bahamon, T.; Bonfond, B.; Bracken, C.; Brandt, P.; Briand, C.; Briois, C.; Brooks, S.; Castillo-Rogez, J.; Cavalié, T.; Christophe, B.; Coates, A. J.; Collinson, G.; Cooper, J. F.; Costa-Sitja, M.; Courtin, R.; Daglis, I. A.; de Pater, I.; Desai, M.; Dirkx, D.; Dougherty, M. K.; Ebert, R. W.; Filacchione, G.; Fletcher, L. N.; Fortney, J.; Gerth, I.; Grassi, D.; Grodent, D.; Grün, E.; Gustin, J.; Hedman, M.; Helled, R.; Henri, P.; Hess, S.; Hillier, J. K.; Hofstadter, M. H.; Holme, R.; Horanyi, M.; Hospodarsky, G.; Hsu, S.; Irwin, P.; Jackman, C. M.; Karatekin, O.; Kempf, S.; Khalisi, E.; Konstantinidis, K.; Krüger, H.; Kurth, W. S.; Labrianidis, C.; Lainey, V.; Lamy, L. L.; Laneuville, M.; Lucchesi, D.; Luntzer, A.; MacArthur, J.; Maier, A.; Masters, A.; McKenna-Lawlor, S.; Melin, H.; Milillo, A.; Moragas-Klostermeyer, G.; Morschhauser, A.; Moses, J. I.; Mousis, O.; Nettelmann, N.; Neubauer, F. M.; Nordheim, T.; Noyelles, B.; Orton, G. S.; Owens, M.; Peron, R.; Plainaki, C.; Postberg, F.; Rambaux, N.; Retherford, K.; Reynaud, S.; Roussos, E.; Russell, C. T.; Rymer, A. M.; Sallantin, R.; Sánchez-Lavega, A.; Santolik, O.; Saur, J.; Sayanagi, K. M.; Schenk, P.; Schubert, J.; Sergis, N.; Sittler, E. C.; Smith, A.; Spahn, F.; Srama, R.; Stallard, T.; Sterken, V.; Sternovsky, Z.; Tiscareno, M.; Tobie, G.; Tosi, F.; Trieloff, M.; Turrini, D.; Turtle, E. P.; Vinatier, S.; Wilson, R.; Zarka, P.

    2014-12-01

    Giant planets helped to shape the conditions we see in the Solar System today and they account for more than 99% of the mass of the Sun's planetary system. They can be subdivided into the Ice Giants (Uranus and Neptune) and the Gas Giants (Jupiter and Saturn), which differ from each other in a number of fundamental ways. Uranus, in particular is the most challenging to our understanding of planetary formation and evolution, with its large obliquity, low self-luminosity, highly asymmetrical internal field, and puzzling internal structure. Uranus also has a rich planetary system consisting of a system of inner natural satellites and complex ring system, five major natural icy satellites, a system of irregular moons with varied dynamical histories, and a highly asymmetrical magnetosphere. Voyager 2 is the only spacecraft to have explored Uranus, with a flyby in 1986, and no mission is currently planned to this enigmatic system. However, a mission to the uranian system would open a new window on the origin and evolution of the Solar System and would provide crucial information on a wide variety of physicochemical processes in our Solar System. These have clear implications for understanding exoplanetary systems. In this paper we describe the science case for an orbital mission to Uranus with an atmospheric entry probe to sample the composition and atmospheric physics in Uranus' atmosphere. The characteristics of such an orbiter and a strawman scientific payload are described and we discuss the technical challenges for such a mission. This paper is based on a white paper submitted to the European Space Agency's call for science themes for its large-class mission programme in 2013.

  12. KEPLER-63b: A GIANT PLANET IN A POLAR ORBIT AROUND A YOUNG SUN-LIKE STAR

    SciTech Connect

    Sanchis-Ojeda, Roberto; Winn, Joshua N.; Albrecht, Simon; Marcy, Geoffrey W.; Isaacson, Howard; Howard, Andrew W.; Johnson, John Asher; Torres, Guillermo; Carter, Joshua A.; Dawson, Rebekah I.; Geary, John C.; Campante, Tiago L.; Chaplin, William J.; Davies, Guy R.; Lund, Mikkel N.; Buchhave, Lars A.; Everett, Mark E.; Fischer, Debra A.; Gilliland, Ronald L.; Horch, Elliott P.; and others

    2013-09-20

    We present the discovery and characterization of a giant planet orbiting the young Sun-like star Kepler-63 (KOI-63, m{sub Kp} = 11.6, T{sub eff} = 5576 K, M{sub *} = 0.98 M{sub ☉}). The planet transits every 9.43 days, with apparent depth variations and brightening anomalies caused by large starspots. The planet's radius is 6.1 ± 0.2 R{sub ⊕}, based on the transit light curve and the estimated stellar parameters. The planet's mass could not be measured with the existing radial-velocity data, due to the high level of stellar activity, but if we assume a circular orbit, then we can place a rough upper bound of 120 M{sub ⊕} (3σ). The host star has a high obliquity (ψ = 104°), based on the Rossiter-McLaughlin effect and an analysis of starspot-crossing events. This result is valuable because almost all previous obliquity measurements are for stars with more massive planets and shorter-period orbits. In addition, the polar orbit of the planet combined with an analysis of spot-crossing events reveals a large and persistent polar starspot. Such spots have previously been inferred using Doppler tomography, and predicted in simulations of magnetic activity of young Sun-like stars.

  13. Dynamics of Orbits near 3:1 Resonance in the Earth-Moon System

    NASA Technical Reports Server (NTRS)

    Dichmann, Donald J.; Lebois, Ryan; Carrico, John P., Jr.

    2013-01-01

    The Interstellar Boundary Explorer (IBEX) spacecraft is currently in a highly elliptical orbit around Earth with a period near 3:1 resonance with the Moon. Its orbit is oriented so that apogee does not approach the Moon. Simulations show this orbit to be remarkably stable over the next twenty years. This article examines the dynamics of such orbits in the Circular Restricted 3-Body Problem (CR3BP). We look at three types of periodic orbits, each exhibiting a type of symmetry of the CR3BP. For each of the orbit types, we assess the local stability using Floquet analysis. Although not all of the periodic solutions are stable in the mathematical sense, any divergence is so slow as to produce practical stability over several decades. We use Poincare maps with twenty-year propagations to assess the nonlinear stability of the orbits, where the perturbation magnitudes are related to the orbit uncertainty for the IBEX mission. Finally we show that these orbits belong to a family of orbits connected in a bifurcation diagram that exhibits exchange of stability. The analysis of these families of period orbits provides a valuable starting point for a mission orbit trade study.

  14. The confinement induced resonance in spin-orbit coupled cold atoms with Raman coupling

    PubMed Central

    Zhang, Yi-Cai; Song, Shu-Wei; Liu, Wu-Ming

    2014-01-01

    The confinement induced resonance provides an indispensable tool for the realization of the low-dimensional strongly interacting quantum system. Here, we investigate the confinement induced resonance in spin-orbit coupled cold atoms with Raman coupling. We find that the quasi-bound levels induced by the spin-orbit coupling and Raman coupling result in the Feshbach-type resonances. For sufficiently large Raman coupling, the bound states in one dimension exist only for sufficiently strong attractive interaction. Furthermore, the bound states in quasi-one dimension exist only for sufficient large ratio of the length scale of confinement to three dimensional s-wave scattering length. The Raman coupling substantially changes the confinement-induced resonance position. We give a proposal to realize confinement induced resonance through increasing Raman coupling strength in experiments. PMID:24862314

  15. The disruption of multiplanet systems through resonance with a binary orbit.

    PubMed

    Touma, Jihad R; Sridhar, S

    2015-08-27

    Most exoplanetary systems in binary stars are of S-type, and consist of one or more planets orbiting a primary star with a wide binary stellar companion. Planetary eccentricities and mutual inclinations can be large, perhaps forced gravitationally by the binary companion. Earlier work on single planet systems appealed to the Kozai-Lidov instability wherein a sufficiently inclined binary orbit excites large-amplitude oscillations in the planet's eccentricity and inclination. The instability, however, can be quenched by many agents that induce fast orbital precession, including mutual gravitational forces in a multiplanet system. Here we report that orbital precession, which inhibits Kozai-Lidov cycling in a multiplanet system, can become fast enough to resonate with the orbital motion of a distant binary companion. Resonant binary forcing results in dramatic outcomes ranging from the excitation of large planetary eccentricities and mutual inclinations to total disruption. Processes such as planetary migration can bring an initially non-resonant system into resonance. As it does not require special physical or initial conditions, binary resonant driving is generic and may have altered the architecture of many multiplanet systems. It can also weaken the multiplanet occurrence rate in wide binaries, and affect planet formation in close binaries. PMID:26310763

  16. Extremely narrow resonances, giant sensitivity and field enhancement in low-loss waveguide sensors

    NASA Astrophysics Data System (ADS)

    Nesterenko, D. V.; Hayashi, S.; Sekkat, Z.

    2016-06-01

    Low-loss waveguides (WGs), which support excitation of waveguide modes (WMs), are based on a dielectric WG separated from an absorptive film by a low-index dielectric spacer layer. We perform numerical and analytical study of the impact of the losses imposed to the WG in a planar sensing structure in the Kretschmann configuration on the resonance properties of the excitation. We demonstrate that the loss degree of the WMs can be controlled by the thickness of the spacer layer for both s and p polarizations. Extremely narrow resonances are discovered in the reflectivity spectra due to excitation of the low-loss WMs, and the maximum of the estimated sensitivity by intensity is found to be of 105-fold higher as compared to the conventional surface plasmon and WG-coupled surface plasmon sensors. We reveal the giant field intensity enhancement of 107-fold on the surface of the sensing structure in aqueous sensing media that can provide stronger fluorescence intensity at lower sample volumes for fluorescent labeling sensing.

  17. Unstable Resonant Orbits near Earth and Their Applications in Planetary Missions

    NASA Technical Reports Server (NTRS)

    Parker, Jeffrey S.; Lo, Martin W.

    2004-01-01

    This paper explores the uses of planar, simple-periodic symmetrical families of orbits in mission designs in the Earth-Moon system. This classification is defined as the planar periodic orbits that pierce the x-axis in the rotating frame exactly twice per orbit where each piercing is orthogonal to the x-axis. A continuation method has been used to explore several families of this class of orbit in the Earth-Moon restricted three-body system. The invariant manifolds of the unstable orbits in each of these families are then produced and several mission designs are discussed that take advantage of these manifolds. Focus is given to mission designs that implement resonant orbits that periodically fly by the moon.

  18. Theory of Resonance Influence of Sawtooth Crashes on Ions with Large Orbit Width

    SciTech Connect

    R.B. White; V.V. Lutsenko; Y.I. Kolesnichenko; Y.V. Yakovenko

    1998-02-01

    The role of resonances in the sawtooth-crash-induced redistribution of fast ions is investigated. In particular, the conditions of wave-particle resonant interaction in the presence of the equilibrium electric field and the mode rotation are obtained, and effects of sawteeth on the resonant particles with arbitrary width of non-perturbed orbits are studied. It is found that resonances play the dominant role in the transport of ions having sufficiently high energy. It is shown that the resonance regions may overlap, in which case the resonant particles may constitute the main fraction of the fast ion population in the sawtooth mixing region. The behavior of the resonant particles is studied both by constructing a Poincaré map and analytically, by means of the adiabatic invariant derived in this paper and calculation of the characteristic frequencies of the particle motion.

  19. DETECTABILITY AND ERROR ESTIMATION IN ORBITAL FITS OF RESONANT EXTRASOLAR PLANETS

    SciTech Connect

    Giuppone, C. A.; Beauge, C.; Tadeu dos Santos, M.; Ferraz-Mello, S.; Michtchenko, T. A.

    2009-07-10

    We estimate the conditions for detectability of two planets in a 2/1 mean-motion resonance from radial velocity data, as a function of their masses, number of observations and the signal-to-noise ratio. Even for a data set of the order of 100 observations and standard deviations of the order of a few meters per second, we find that Jovian-size resonant planets are difficult to detect if the masses of the planets differ by a factor larger than {approx}4. This is consistent with the present population of real exosystems in the 2/1 commensurability, most of which have resonant pairs with similar minimum masses, and could indicate that many other resonant systems exist, but are currently beyond the detectability limit. Furthermore, we analyze the error distribution in masses and orbital elements of orbital fits from synthetic data sets for resonant planets in the 2/1 commensurability. For various mass ratios and number of data points we find that the eccentricity of the outer planet is systematically overestimated, although the inner planet's eccentricity suffers a much smaller effect. If the initial conditions correspond to small-amplitude oscillations around stable apsidal corotation resonances, the amplitudes estimated from the orbital fits are biased toward larger amplitudes, in accordance to results found in real resonant extrasolar systems.

  20. On the stability of resonant rotation of a symmetric satellite in an elliptical orbit

    NASA Astrophysics Data System (ADS)

    Bardin, Boris S.; Chekina, Evgeniya A.

    2016-07-01

    We deal with the stability problem of resonant rotation of a symmetric rigid body about its center of mass in an elliptical orbit. The resonant rotation is a planar motion such that the body completes one rotation in absolute space during two orbital revolutions of its center of mass. In [1-3] the stability analysis of the above resonant rotation with respect to planar perturbations has been performed in detail. In this paper we study the stability of the resonant rotation in an extended formulation taking into account both planar and spatial perturbations. By analyzing linearized equations of perturbed motion, we found eccentricity intervals, where the resonant rotation is unstable. Outside of these intervals a nonlinear stability study has been performed and subintervals of formal stability and stability for most initial data have been found. In addition, the instability of the resonant rotation was established at several eccentricity values corresponding to the third and fourth order resonances. Our study has also shown that in linear approximation the spatial perturbations have no effect on the stability of the resonant rotation, whereas in a nonlinear system they can lead to its instability at some resonant values of the eccentricity.

  1. The Anglo-Australian Planet Search. XX. A Solitary Ice-giant Planet Orbiting HD 102365

    NASA Astrophysics Data System (ADS)

    Tinney, C. G.; Butler, R. Paul; Jones, Hugh R. A.; Wittenmyer, Robert A.; O'Toole, Simon; Bailey, Jeremy; Carter, Brad D.

    2011-02-01

    We present 12 years of precision Doppler data for the very nearby G3 star HD 102365, which reveals the presence of a Neptune-like planet with a 16.0 M Earth minimum mass in a 122.1 day orbit. Very few "Super Earth" planets have been discovered to date in orbits this large and those that have been found reside in multiple systems of between three and six planets. HD 102365 b, in contrast, appears to orbit its star in splendid isolation. Analysis of the residuals to our Keplerian fit for HD 102365 b indicates that there are no other planets with minimum mass above 0.3 M Jup orbiting within 5 AU and no other "Super Earths" more massive than 10 M Earth orbiting at periods shorter than 50 days. At periods of less than 20 days these limits drop to as low as 6 M Earth. There are now 32 exoplanets known with minimum mass below 20 M Earth, and interestingly the period distributions of these low-mass planets seem to be similar whether they orbit M-, K-, or G-type dwarfs. Based on observations obtained at the Anglo-Australian Telescope, Siding Spring, Australia.

  2. THE ANGLO-AUSTRALIAN PLANET SEARCH. XX. A SOLITARY ICE-GIANT PLANET ORBITING HD 102365

    SciTech Connect

    Tinney, C. G.; Wittenmyer, Robert A.; Bailey, Jeremy; Butler, R. Paul; Jones, Hugh R. A.; O'Toole, Simon; Carter, Brad D.

    2011-02-01

    We present 12 years of precision Doppler data for the very nearby G3 star HD 102365, which reveals the presence of a Neptune-like planet with a 16.0 M{sub Earth} minimum mass in a 122.1 day orbit. Very few 'Super Earth' planets have been discovered to date in orbits this large and those that have been found reside in multiple systems of between three and six planets. HD 102365 b, in contrast, appears to orbit its star in splendid isolation. Analysis of the residuals to our Keplerian fit for HD 102365 b indicates that there are no other planets with minimum mass above 0.3 M{sub Jup} orbiting within 5 AU and no other 'Super Earths' more massive than 10 M{sub Earth} orbiting at periods shorter than 50 days. At periods of less than 20 days these limits drop to as low as 6 M{sub Earth}. There are now 32 exoplanets known with minimum mass below 20 M{sub Earth}, and interestingly the period distributions of these low-mass planets seem to be similar whether they orbit M-, K-, or G-type dwarfs.

  3. On the establishment and evolution of orbit-orbit resonances. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Yoder, C. F.

    1973-01-01

    A theory which suggests that in the case of planetary satellites, a tidally induced torque acting on the satellites may play an essential role on the evolution of the observed resonances is investigated as it applies to the three resonances among pairs of satellites of Saturn. Three stages are investigated: a theoretical description of transition is developed for a simple time dependent pendulum plus constant applied torque; the two body gravitational interaction is expanded and reduced to a one dimensional time independent Hamiltonion; and the model is applied to Saturn resonances. Although the theory proves successful in the Saturn case, it is less successful in the Tital-Hyperion case in providing a resonable time scale for the damping of the amplitude of liberation.

  4. Harmonic oscillators and resonance series generated by a periodic unstable classical orbit

    NASA Technical Reports Server (NTRS)

    Kazansky, A. K.; Ostrovsky, Valentin N.

    1995-01-01

    The presence of an unstable periodic classical orbit allows one to introduce the decay time as a purely classical magnitude: inverse of the Lyapunov index which characterizes the orbit instability. The Uncertainty Relation gives the corresponding resonance width which is proportional to the Planck constant. The more elaborate analysis is based on the parabolic equation method where the problem is effectively reduced to the multidimensional harmonic oscillator with the time-dependent frequency. The resonances form series in the complex energy plane which is equidistant in the direction perpendicular to the real axis. The applications of the general approach to various problems in atomic physics are briefly exposed.

  5. Orbital resonances and planetary accretion in the early solar system evolution

    NASA Astrophysics Data System (ADS)

    Torbett, M. V.

    1982-03-01

    The solar system, in its early evolution, is thought to have consisted of an accretion disk around a growing central protostar. The accretion disk from which the planets ultimately formed can play a significant role in the processes of planetary and solar formation. As well as leading, by thermalization of orbital motions in the disk, to bipolar flows in the T Tauri stage of stellar evolution, the disk can influence the course of planetary accumulation. By virtue of its essentially solar composition, Jupiter was formed before the accretion disk was removed. This first formed planet then gravitationally imposed a harmonic structure on the planetesimal swarm through its commensurability resonances. Accelerated growth of planetesimals in orbital resonance with Jupiter resulted in runaway growth producing planetary embryos. These embryos accelerated growth at their own resonances in a process that propagation inward and outward forming a resonant configuration of embryos.

  6. Artificial satellites orbits in 2:1 resonance: GPS constellation

    NASA Astrophysics Data System (ADS)

    Sampaio, J. C.; Neto, A. G. S.; Fernandes, S. S.; Vilhena de Moraes, R.; Terra, M. O.

    2012-12-01

    In this work, the resonance problem in the artificial satellites motion is studied. The development of the geopotential includes the zonal harmonics J20 and J40 and the tesseral harmonics J22 and J42. Through an averaging procedure and successive Mathieu transformations, the order of dynamical system is reduced and the final system is solved by numerical integration. In the simplified dynamical model, three critical angles are studied. The half-width of the separatrix is calculated through a linearized model which describes the behavior of the dynamical system in a neighborhood of each critical angle. Through the resonance overlap criterion the possible regular and irregular motions are investigated by the time behavior of the semi-major axis, argument of perigee and eccentricity. The largest Lyapunov exponent is used as tool to verify the chaotic motion.

  7. Disruption of planetary orbits through evection resonance with an external companion: circumbinary planets and multiplanet systems

    NASA Astrophysics Data System (ADS)

    Xu, Wenrui; Lai, Dong

    2016-07-01

    Planets around binary stars and those in multiplanet systems may experience resonant eccentricity excitation and disruption due to perturbations from a distant stellar companion. This `evection resonance' occurs when the apsidal precession frequency of the planet, driven by the quadrupole associated with the inner binary or the other planets, matches the orbital frequency of the external companion. We develop an analytic theory to study the effects of evection resonance on circumbinary planets and multiplanet systems. We derive the general conditions for effective eccentricity excitation or resonance capture of the planet as the system undergoes long-term evolution. Applying to circumbinary planets, we show that inward planet migration may lead to eccentricity growth due to evection resonance with an external perturber, and planets around shrinking binaries may not survive the resonant eccentricity growth. On the other hand, significant eccentricity excitation in multiplanet systems occurs in limited parameter space of planet and binary semimajor axes, and requires the planetary migration to be sufficiently slow.

  8. Intense {gamma}-Ray Source in the Giant-Dipole-Resonance Range Driven by 10-TW Laser Pulses

    SciTech Connect

    Giulietti, A.; Gamucci, A.; Gizzi, L. A.; Labate, L.; Bourgeois, N.; Marques, J. R.; Ceccotti, T.; Dobosz, S.; D'Oliveira, P.; Monot, P.; Popescu, H.; Reau, F.; Martin, P.; Galy, J.; Hamilton, D. J.; Giulietti, D.

    2008-09-05

    A {gamma}-ray source with an intense component around the giant dipole resonance for photonuclear absorption has been obtained via bremsstrahlung of electron bunches driven by a 10-TW tabletop laser. 3D particle-in-cell simulation proves the achievement of a nonlinear regime leading to efficient acceleration of several sequential electron bunches per each laser pulse. The rate of the {gamma}-ray yield in the giant dipole resonance region (8

  9. Intense gamma-ray source in the giant-dipole-resonance range driven by 10-TW laser pulses.

    PubMed

    Giulietti, A; Bourgeois, N; Ceccotti, T; Davoine, X; Dobosz, S; D'Oliveira, P; Galimberti, M; Galy, J; Gamucci, A; Giulietti, D; Gizzi, L A; Hamilton, D J; Lefebvre, E; Labate, L; Marquès, J R; Monot, P; Popescu, H; Réau, F; Sarri, G; Tomassini, P; Martin, P

    2008-09-01

    A gamma-ray source with an intense component around the giant dipole resonance for photonuclear absorption has been obtained via bremsstrahlung of electron bunches driven by a 10-TW tabletop laser. 3D particle-in-cell simulation proves the achievement of a nonlinear regime leading to efficient acceleration of several sequential electron bunches per each laser pulse. The rate of the gamma-ray yield in the giant dipole resonance region (8

  10. Post Surgical Giant Epidermal Inclusion Cyst of the Lid and Orbit- A Rare Case

    PubMed Central

    Mandal, Aparna; Bandyopadhya, Arghya

    2015-01-01

    Epidermoid cyst within the lid and orbit is extremely rare. Epidermoid tumours are inclusion of ectodermal elements in the site not normally containing these structures. It is of two types; primary type related to implantation of ectoderm at the time of closure of the neural groove and secondary type caused by post traumatic inclusion of the surface epithelium. A 45-year-old male had complaint of swelling on the right upper lid and orbital region. It first appeared two years back. It was painless progressively increased in size and shape. There was difficulty in opening of eye lid due to large swelling, feeling of heaviness in the right upper lid and occasional headache. There was history of right eye ocular infection following vegetative matter injury three years back. Evisceration of right eye was done for aforementioned reason. USG report shows cystic encapsulated mass with calcification foci in right upper lid-orbital region with fat component. MRI right orbit shows fairly large hyperintense cystic lesion seen involving right orbit with posterior extension up to optic canal. No intracranial extension. FNAC confirmed epidermal inclusion cyst. We did upper lid reconstruction with removal of mass. We have successfully removed the mass without any complication and with one year follow-up there is no recurrence. PMID:26500932

  11. Giant resonances in {sup 238}U within the quasiparticle random-phase approximation with the Gogny force

    SciTech Connect

    Peru, S.; Gosselin, G.; Martini, M.; Dupuis, M.; Hilaire, S.

    2011-01-15

    Fully consistent axially-symmetric deformed quasiparticle random-phase approximation (QRPA) calculations have been performed, using the same Gogny D1S effective force for both the Hartree-Fock-Bogolyubov mean field and QRPA matrix. New implementation of this approach leads to the applicability of QRPA to heavy deformed nuclei. Giant resonances and low-energy collective states for monopole, dipole, quadrupole, and octupole modes are predicted for the heavy deformed nucleus {sup 238}U and compared with experimental data.

  12. The In Situ Formation of Giant Planets at Short Orbital Periods

    NASA Astrophysics Data System (ADS)

    Boley, Aaron C.; Gladman, Brett; Granados Contreras, A. Paula

    2016-05-01

    We propose that two of the most surprising results so far among exoplanet discoveries are related: the existences of both hot Jupiters and the high frequency of multi-planet systems with periods P < 200 days. In this paradigm, the vast majority of stars rapidly form along with multiple close-in planets in the mass range of Mars to super-Earths/mini-Neptunes. Such systems of tightly packed inner planets are metastable, with the time scale of the dynamical instability having a major influence on final planet types. In most cases, the planets consolidate into a system of fewer, more massive planets, but long after the circumstellar gas disk has dissipated. This can yield planets with masses above the traditional critical core of ~10 Mearth yielding short-period giants that lack abundant gas. A rich variety of physical states are also possible given the range of collisional outcomes and formation time of the close-in planets. However, when dynamical consolidation occurs before gas dispersal, a critical core can form that then grows via gas capture into a short-period gas giant. In this picture the majority of Hot and Warm Jupiters formed locally, rather than migrating down from larger distances.

  13. Orbital parameters of V 0332+53 from 2015 giant outburst data

    NASA Astrophysics Data System (ADS)

    Doroshenko, V.; Tsygankov, S.; Santangelo, A.

    2016-05-01

    We present the updated orbital solution for the transient Be X-ray binary V 0332+53, which we obtained by complementing historical measurements with the data from the gamma-ray burst monitor onboard Fermi. These were acquired during the outburst in June-October 2015. We modeled the observed changes in the spin-frequency of the pulsar and deduced the orbital parameters of the system. We significantly improved existing constrains and show that contrary to previous findings, no change in orbital parameters is required to explain the spin evolution of the source during the outbursts in 1983, 2005, and 2015. The reconstructed intrinsic spin-up of the neutron star during the latest outburst is found to be comparable with previously observed values and predictions of the accretion torque theory.

  14. Experimental study of playback giant magnetic resonance head nonlinearity in perpendicular recording

    NASA Astrophysics Data System (ADS)

    Luo, P.; Stoev, K.; Liu, F.; Vadde, A.; Gibbons, M.; Lederman, M.; Re, M.

    2003-05-01

    In this article, nonlinear distortions of the playback giant magnetic resonance (GMR) sensor in perpendicular recording are characterized in both time and frequency domains. We use three perpendicular media with different Mrt (0.46, 0.6, and 0.8 emu/cm2) and two groups of similar magnetic-read width (MRW) but different junction type [contiguous junction (CJ) and lead-over-lay (LOL)] GMR heads. Square-wave patterns at moderate densities are recorded to minimize NLTS, partial erasure, and transition broadening effects. Both time- and frequency-domain measurements indicate that the LOL-type GMR heads show playback nonlinearity (7%-23%), while the CJ-type GMR heads do not. Micromagnetic simulation is utilized to understand the hard bias field with different junction designs. The result indicates that the hard bias (HB) field in LOL type (HB field ˜6.9 Oe) at the air bearing surface (ABS) and stripe center is much lower than that in CJ type (HB field ˜54.0 Oe). Therefore, the free layer with large HB-HB distance will be more susceptible to saturation.

  15. Temperature dependence of the giant dipole resonance width in 152Gd

    NASA Astrophysics Data System (ADS)

    Ghosh, C.; Mishra, G.; Rhine Kumar, A. K.; Dokania, N.; Nanal, V.; Pillay, R. G.; Kumar, Suresh; Rout, P. C.; Joshi, Sandeep; Arumugam, P.

    2016-07-01

    To investigate the dependence of giant dipole resonance (GDR) width on temperature (T ) and angular momentum (J ), high energy γ -ray spectra were measured in the reaction 28Si+124Sn at E28Si=135 MeV. The J information was deduced from multiplicity of low-energy γ rays. The GDR parameters, namely, the centroid energy and width are extracted using statistical model analysis. The observed variation of the GDR width for T ˜1.2 -1.37 MeV and J ˜20 ℏ -40 ℏ is consistent with the universal scaling given by Kusnezov et al., which is applicable in the liquid-drop regime. The GDR input cross sections extracted from the statistical model best fits are compared with thermal shape fluctuation model (TSFM) calculations and are found to be in good agreement. The TSFM calculations predominantly favor the noncollective oblate shape, while the statistical model fit with both prolate and oblate shapes describes the data. The present data together with earlier measurements indicate a very slow variation of the GDR width for T ˜1.2 to 1.5 MeV. The observed trend is well explained by the TSFM calculations, although the calculated values are ˜4 %-13% higher than the data.

  16. Giant dipole resonance width in nuclei near Sn at low temperature and high angular momentum

    SciTech Connect

    Bhattacharya, Srijit; Mukhopadhyay, S.; Pandit, Deepak; Pal, Surajit; Bhattacharya, S.; Bhattacharya, C.; Banerjee, K.; Kundu, S.; Rana, T. K.; Dey, A.; Mukherjee, G.; Ghosh, T.; Gupta, D.; Banerjee, S. R.

    2008-02-15

    High energy {gamma} rays in coincidence with low energy yrast {gamma} rays have been measured from {sup 113}Sb, at excitation energies of 109 and 122 MeV, formed by bombarding {sup 20}Ne on {sup 93}Nb at projectile energies of 145 and 160 MeV, respectively, to study the role of angular momentum (J) and temperature (T) over giant dipole resonance (GDR) width ({gamma}). The maximum populated angular momenta for fusion were 67({Dirac_h}/2{pi}) and 73({Dirac_h}/2{pi}), respectively, for the above-mentioned beam energies. The high energy photons were detected using a Large Area Modular BaF{sub 2} Detector Array (LAMBDA) along with a 24-element multiplicity filter. After pre-equilibrium corrections, the excitation energy E* was averaged over the decay steps of the compound nucleus (CN). The average values of temperature, angular momentum, CN mass, etc., have been calculated using the statistical model code CASCADE. Using those average values, results show the systematic increase of GDR width with T, which is consistent with Kusnezov parametrization and the thermal shape fluctuation model (TSFM). The rise of GDR width with temperature also supports the assumptions of adiabatic coupling in the TSFM. But the GDR widths and corresponding reduced plots with J are not consistent with those of the theoretical model at high spins.

  17. Giant dipole resonance width in nuclei near Sn at low temperature and high angular momentum

    NASA Astrophysics Data System (ADS)

    Bhattacharya, Srijit; Mukhopadhyay, S.; Pandit, Deepak; Pal, Surajit; de, A.; Bhattacharya, S.; Bhattacharya, C.; Banerjee, K.; Kundu, S.; Rana, T. K.; Dey, A.; Mukherjee, G.; Ghosh, T.; Gupta, D.; Banerjee, S. R.

    2008-02-01

    High energy γ rays in coincidence with low energy yrast γ rays have been measured from Sb113, at excitation energies of 109 and 122 MeV, formed by bombarding Ne20 on Nb93 at projectile energies of 145 and 160 MeV, respectively, to study the role of angular momentum (J) and temperature (T) over giant dipole resonance (GDR) width (Γ). The maximum populated angular momenta for fusion were 67ℏ and 73ℏ, respectively, for the above-mentioned beam energies. The high energy photons were detected using a Large Area Modular BaF2 Detector Array (LAMBDA) along with a 24-element multiplicity filter. After pre-equilibrium corrections, the excitation energy E* was averaged over the decay steps of the compound nucleus (CN). The average values of temperature, angular momentum, CN mass, etc., have been calculated using the statistical model code CASCADE. Using those average values, results show the systematic increase of GDR width with T, which is consistent with Kusnezov parametrization and the thermal shape fluctuation model (TSFM). The rise of GDR width with temperature also supports the assumptions of adiabatic coupling in the TSFM. But the GDR widths and corresponding reduced plots with J are not consistent with those of the theoretical model at high spins.

  18. /sup 31/P nuclear magnetic resonance measurements of intracellular pH in giant barnacle muscle

    SciTech Connect

    Hamm, J.R.; Yue, G.M.

    1987-01-01

    The accuracy of intracellular pH (pH/sub i/) measurements by /sup 31/P nuclear magnetic resonance (NMR) spectroscopy was examined in single muscle fibers from the giant barnacle, Balanus nubilis. The pH/sub i/ was derived from the chemical shifts of 2-deoxy-D-glucose-6-phosphate and inorganic phosphate. In fibers superfused with sea water at pH 7.7, pH/sub i/ = 7.30 +/- 0.02 at 20/sup 0/C. Experimentally induced pH/sub i/ changes were followed with a time resolution of 3 min. Intracellular alkalinization was induced by exposure to NH/sub 3/Cl and intracellular acidification followed when NH/sub 3/ was removed. Then acid extrusion was stimulated by exposure to bicarbonate containing sea water. In single muscle fibers /sup 31/P NMR results were in excellent agreement with microelectrode studies over the pH range of 6.5 to 8.0. The initial acid extrusion rate was 1.7 +/- 0.3 mmol x 1/sup -1/ x min/sup -1/ at pH/sub i/ 6.75. The authors results showed that /sup 31/P NMR is a reliable in vivo pH probe.

  19. 31P nuclear magnetic resonance measurements of intracellular pH in giant barnacle muscle.

    PubMed

    Hamm, J R; Yue, G M

    1987-01-01

    The accuracy of intracellular pH (pHi) measurements by 31P nuclear magnetic resonance (NMR) spectroscopy was examined in single muscle fibers from the giant barnacle, Balanus nubilis. The pHi was derived from the chemical shifts of 2-deoxy-D-glucose-6-phosphate and inorganic phosphate. In fibers superfused with sea water at pH 7.7, pHi = 7.30 +/- 0.02 at 20 degrees C. Experimentally induced pHi changes were followed with a time resolution of 3 min. Intracellular alkalinization was induced by exposure to NH4Cl and intracellular acidification followed when NH3 was removed. Then acid extrusion was stimulated by exposure to bicarbonate containing sea water. In single muscle fibers 31P NMR results were in excellent agreement with microelectrode studies over the pH range of 6.5 to 8.0. The initial acid extrusion rate was 1.7 +/- 0.3 mmol X l-1 X min-1 at pHi 6.75. Our results showed that 31P NMR is a reliable in vivo pH probe. PMID:3812665

  20. Tunable giant spin hall conductivities in a strong spin-orbit semimetal: Bi(1-x) Sb(x).

    PubMed

    Şahin, Cüneyt; Flatté, Michael E

    2015-03-13

    Intrinsic spin Hall conductivities are calculated for strong spin-orbit Bi(1-x)Sb(x) semimetals, from the Kubo formula and using Berry curvatures evaluated throughout the Brillouin zone from a tight-binding Hamiltonian. Nearly crossing bands with strong spin-orbit interaction generate giant spin Hall conductivities in these materials, ranging from 474 (ℏ/e)(Ω  cm)^{-1} for bismuth to 96 (ℏ/e)(Ω  cm)^{-1} for antimony; the value for bismuth is more than twice that of platinum. The large spin Hall conductivities persist for alloy compositions corresponding to a three-dimensional topological insulator state, such as Bi(0.83)Sb(0.17). The spin Hall conductivity could be changed by a factor of 5 for doped Bi, or for Bi(0.83)Sb(0.17), by changing the chemical potential by 0.5 eV, suggesting the potential for doping or voltage tuned spin Hall current. PMID:25815962

  1. Cyclotron resonance of figure-of-eight orbits in a type-II Weyl semimetal

    NASA Astrophysics Data System (ADS)

    Koshino, Mikito

    2016-07-01

    We study the cyclotron resonance in the electron-hole joint Fermi surface of a type-II Weyl semimetal. In magnetic field, the electron and hole pockets touching at the Weyl node are hybridized to form quantized Landau levels corresponding to semiclassical 8-shaped orbits. We calculate the dynamical conductivities for the electric fields oscillating in x and y directions and find that the resonant frequencies in x and y differ by a factor of two, reflecting the figure-of-eight electron motion in real space. The peculiar anisotropy in the cyclotron resonance serves as a unique characteristic of the dumbbell-like Fermi surface.

  2. Study of orbitally excited B mesons and evidence for a new Bπ resonance

    NASA Astrophysics Data System (ADS)

    Aaltonen, T.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J. A.; Arisawa, T.; Artikov, A.; Asaadi, J.; Ashmanskas, W.; Auerbach, B.; Aurisano, A.; Azfar, F.; Badgett, W.; Bae, T.; Barbaro-Galtieri, A.; Barnes, V. E.; Barnett, B. A.; Barria, P.; Bartos, P.; Bauce, M.; Bedeschi, F.; Behari, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Bhatti, A.; Bland, K. R.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Bortoletto, D.; Boudreau, J.; Boveia, A.; Brigliadori, L.; Bromberg, C.; Brucken, E.; Budagov, J.; Budd, H. S.; Burkett, K.; Busetto, G.; Bussey, P.; Butti, P.; Buzatu, A.; Calamba, A.; Camarda, S.; Campanelli, M.; Canelli, F.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, S.; Casal, B.; Casarsa, M.; Castro, A.; Catastini, P.; Cauz, D.; Cavaliere, V.; Cavalli-Sforza, M.; Cerri, A.; Cerrito, L.; Chen, Y. C.; Chertok, M.; Chiarelli, G.; Chlachidze, G.; Cho, K.; Chokheli, D.; Clark, A.; Clarke, C.; Convery, M. E.; Conway, J.; Corbo, M.; Cordelli, M.; Cox, C. A.; Cox, D. J.; Cremonesi, M.; Cruz, D.; Cuevas, J.; Culbertson, R.; d'Ascenzo, N.; Datta, M.; de Barbaro, P.; Demortier, L.; Deninno, M.; Devoto, F.; D'Errico, M.; Di Canto, A.; Di Ruzza, B.; Dittmann, J. R.; D'Onofrio, M.; Donati, S.; Dorigo, M.; Driutti, A.; Ebina, K.; Edgar, R.; Elagin, A.; Erbacher, R.; Errede, S.; Esham, B.; Farrington, S.; Feindt, M.; Fernández Ramos, J. P.; Field, R.; Flanagan, G.; Forrest, R.; Franklin, M.; Freeman, J. C.; Frisch, H.; Funakoshi, Y.; Galloni, C.; Garfinkel, A. F.; Garosi, P.; Gerberich, H.; Gerchtein, E.; Giagu, S.; Giakoumopoulou, V.; Gibson, K.; Ginsburg, C. M.; Giokaris, N.; Giromini, P.; Giurgiu, G.; Glagolev, V.; Glenzinski, D.; Gold, M.; Goldin, D.; Golossanov, A.; Gomez, G.; Gomez-Ceballos, G.; Goncharov, M.; González López, O.; Gorelov, I.; Goshaw, A. T.; Goulianos, K.; Gramellini, E.; Grinstein, S.; Grosso-Pilcher, C.; Group, R. C.; Guimaraes da Costa, J.; Hahn, S. R.; Han, J. Y.; Happacher, F.; Hara, K.; Hare, M.; Harr, R. F.; Harrington-Taber, T.; Hatakeyama, K.; Hays, C.; Heck, M.; Heinrich, J.; Herndon, M.; Hocker, A.; Hong, Z.; Hopkins, W.; Hou, S.; Hughes, R. E.; Husemann, U.; Hussein, M.; Huston, J.; Introzzi, G.; Iori, M.; Ivanov, A.; James, E.; Jang, D.; Jayatilaka, B.; Jeon, E. J.; Jindariani, S.; Jones, M.; Joo, K. K.; Jun, S. Y.; Junk, T. R.; Kambeitz, M.; Kamon, T.; Karchin, P. E.; Kasmi, A.; Kato, Y.; Ketchum, W.; Keung, J.; Kilminster, B.; Kim, D. H.; Kim, H. S.; Kim, J. E.; Kim, M. J.; Kim, S. B.; Kim, S. H.; Kim, Y. K.; Kim, Y. J.; Kimura, N.; Kirby, M.; Knoepfel, K.; Kondo, K.; Kong, D. J.; Konigsberg, J.; Kotwal, A. V.; Kreps, M.; Kroll, J.; Kruse, M.; Kuhr, T.; Kurata, M.; Laasanen, A. T.; Lammel, S.; Lancaster, M.; Lannon, K.; Latino, G.; Lee, H. S.; Lee, J. S.; Leo, S.; Leone, S.; Lewis, J. D.; Limosani, A.; Lipeles, E.; Lister, A.; Liu, H.; Liu, Q.; Liu, T.; Lockwitz, S.; Loginov, A.; Lucà, A.; Lucchesi, D.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lys, J.; Lysak, R.; Madrak, R.; Maestro, P.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Marchese, L.; Margaroli, F.; Marino, P.; Martínez, M.; Matera, K.; Mattson, M. E.; Mazzacane, A.; Mazzanti, P.; McNulty, R.; Mehta, A.; Mehtala, P.; Mesropian, C.; Miao, T.; Mietlicki, D.; Mitra, A.; Miyake, H.; Moed, S.; Moggi, N.; Moon, C. S.; Moore, R.; Morello, M. J.; Mukherjee, A.; Muller, Th.; Murat, P.; Mussini, M.; Nachtman, J.; Nagai, Y.; Naganoma, J.; Nakano, I.; Napier, A.; Nett, J.; Neu, C.; Nigmanov, T.; Nodulman, L.; Noh, S. Y.; Norniella, O.; Oakes, L.; Oh, S. H.; Oh, Y. D.; Oksuzian, I.; Okusawa, T.; Orava, R.; Ortolan, L.; Pagliarone, C.; Palencia, E.; Palni, P.; Papadimitriou, V.; Parker, W.; Pauletta, G.; Paulini, M.; Paus, C.; Phillips, T. J.; Piacentino, G.; Pianori, E.; Pilot, J.; Pitts, K.; Plager, C.; Pondrom, L.; Poprocki, S.; Potamianos, K.; Prokoshin, F.; Pranko, A.; Ptohos, F.; Punzi, G.; Ranjan, N.; Redondo Fernández, I.; Renton, P.; Rescigno, M.; Rimondi, F.; Ristori, L.; Robson, A.; Rodriguez, T.; Rolli, S.; Ronzani, M.; Roser, R.; Rosner, J. L.; Ruffini, F.; Ruiz, A.; Russ, J.; Rusu, V.; Sakumoto, W. K.; Sakurai, Y.; Santi, L.; Sato, K.; Saveliev, V.; Savoy-Navarro, A.; Schlabach, P.; Schmidt, E. E.; Schwarz, T.; Scodellaro, L.; Scuri, F.; Seidel, S.; Seiya, Y.; Semenov, A.; Sforza, F.; Shalhout, S. Z.; Shears, T.; Shepard, P. F.; Shimojima, M.; Shochet, M.; Shreyber-Tecker, I.; Simonenko, A.; Sliwa, K.; Smith, J. R.; Snider, F. D.; Sorin, V.; Song, H.; Stancari, M.; St. Denis, R.; Stentz, D.; Strologas, J.; Sudo, Y.; Sukhanov, A.; Suslov, I.; Takemasa, K.; Takeuchi, Y.; Tang, J.; Tecchio, M.; Teng, P. K.; Thom, J.; Thomson, E.; Thukral, V.; Toback, D.; Tokar, S.; Tollefson, K.; Tomura, T.; Tonelli, D.; Torre, S.; Torretta, D.; Totaro, P.; Trovato, M.; Ukegawa, F.; Uozumi, S.; Vázquez, F.; Velev, G.; Vellidis, C.; Vernieri, C.; Vidal, M.; Vilar, R.; Vizán, J.; Vogel, M.; Volpi, G.; Wagner, P.; Wallny, R.; Wang, S. M.; Waters, D.; Wester, W. C.; Whiteson, D.; Wicklund, A. B.; Wilbur, S.; Williams, H. H.; Wilson, J. S.; Wilson, P.; Winer, B. L.; Wittich, P.; Wolbers, S.; Wolfe, H.; Wright, T.; Wu, X.; Wu, Z.; Yamamoto, K.; Yamato, D.; Yang, T.; Yang, U. K.; Yang, Y. C.; Yao, W.-M.; Yeh, G. P.; Yi, K.; Yoh, J.; Yorita, K.; Yoshida, T.; Yu, G. B.; Yu, I.; Zanetti, A. M.; Zeng, Y.; Zhou, C.; Zucchelli, S.; CDF Collaboration

    2014-07-01

    Using the full CDF Run II data sample, we report evidence for a new resonance, which we refer to as B(5970), found simultaneously in the B0π+ and B+π- mass distributions with a significance of 4.4 standard deviations. We further report the first study of resonances consistent with orbitally excited B+ mesons and an updated measurement of the properties of orbitally excited B0 and Bs0 mesons. We measure the masses and widths of all states, as well as the relative production rates of the B1, B2*, and B(5970) states and the branching fraction of the Bs2*0 state to either B*+K- and B+K-. Furthermore, we measure the production rates of the orbitally excited B0,+ states relative to the B0,+ ground state. The masses of the new B(5970) resonances are 5978±5(stat)±12(syst) MeV/c2 for the neutral state and 5961±5(stat)±12(syst) MeV /c2 for the charged state, assuming that the resonance decays into Bπ final states. The properties of the orbitally excited and the new B(59700,+) states are compatible with isospin symmetry.

  3. ON THE ORBITAL EVOLUTION OF A GIANT PLANET PAIR EMBEDDED IN A GASEOUS DISK. II. A SATURN-JUPITER CONFIGURATION

    SciTech Connect

    Zhang Hui; Zhou Jilin

    2010-08-10

    We carry out a series of high-resolution (1024 x 1024) hydrodynamic simulations to investigate the orbital evolution of a Saturn-Jupiter pair embedded in a gaseous disk. This work extends the results of our previous work by exploring a different orbital configuration-Jupiter lies outside Saturn (q < 1, where q {identical_to} M{sub i} /M{sub o} is the mass ratio of the inner planet and the outer one). We focus on the effects of different initial separations (d) between the two planets and the various surface density profiles of the disk, where {sigma} {proportional_to} r {sup -}{alpha}. We also compare the results of different orbital configurations of the planet pair. Our results show that (1) when the initial separation is relatively large (d>d {sub iLr}, where d {sub iLr} is the distance between Jupiter and its first inner Lindblad resonance), the two planets undergo divergent migration. However, the inward migration of Saturn could be halted when Jupiter compresses the inner disk in which Saturn is embedded. (2) Convergent migration occurs when the initial separation is smaller (d < d {sub iLr}) and the density slope of the disk is nearly flat ({alpha} < 1/2). Saturn is then forced by Jupiter to migrate inward where the two planets are trapped into mean motion resonances (MMRs), and Saturn may get very close to the central star. (3) In the case of q < 1, the eccentricity of Saturn could be excited to a very high value (e{sub S} {approx} 0.4-0.5) by the MMRs and the system could maintain stability. These results explain the formation of MMRs in the exoplanet systems where the outer planet is more massive than the inner one. It also helps us to understand the origin of the 'hot Jupiter/Saturn' with a highly eccentric orbit.

  4. Resonant mixing of optical orbital and spin angular momentum by using chiral silicon nanosphere clusters.

    PubMed

    Al-Jarro, Ahmed; Biris, Claudiu G; Panoiu, Nicolae C

    2016-04-01

    We present an in-depth analysis of the resonant intermixing between optical orbital and spin angular momentum of Laguerre-Gaussian (LG) beams, mediated by chiral clusters made of silicon nanospheres. In particular, we establish a relationship between the spin and orbital quantum numbers characterizing the LG beam and the order q of the rotation symmetry group q of the cluster of nanospheres for which resonantly enhanced coupling between the two components of the optical angular momentum is observed. Thus, similar to the case of diffraction grating-mediated transfer of linear momentum between optical beams, we demonstrate that clusters of nanospheres that are invariant to specific rotation transformations can efficiently transfer optical angular momentum between LG beams with different quantum numbers. We also discuss the conditions in which the resonant interaction between LG beams and a chiral cluster of nanospheres leads to the generation of superchiral light. PMID:27136989

  5. THE CALIFORNIA PLANET SURVEY IV: A PLANET ORBITING THE GIANT STAR HD 145934 AND UPDATES TO SEVEN SYSTEMS WITH LONG-PERIOD PLANETS

    SciTech Connect

    Katherina Feng, Y.; Wright, Jason T.; Nelson, Benjamin; Wang, Sharon X.; Ford, Eric B.; Marcy, Geoffrey W.; Isaacson, Howard; Howard, Andrew W.

    2015-02-10

    We present an update to seven stars with long-period planets or planetary candidates using new and archival radial velocities from Keck-HIRES and literature velocities from other telescopes. Our updated analysis better constrains orbital parameters for these planets, four of which are known multi-planet systems. HD 24040 b and HD 183263 c are super-Jupiters with circular orbits and periods longer than 8 yr. We present a previously unseen linear trend in the residuals of HD 66428 indicative of an additional planetary companion. We confirm that GJ 849 is a multi-planet system and find a good orbital solution for the c component: it is a 1 M {sub Jup} planet in a 15 yr orbit (the longest known for a planet orbiting an M dwarf). We update the HD 74156 double-planet system. We also announce the detection of HD 145934 b, a 2 M {sub Jup} planet in a 7.5 yr orbit around a giant star. Two of our stars, HD 187123 and HD 217107, at present host the only known examples of systems comprising a hot Jupiter and a planet with a well constrained period greater than 5 yr, and with no evidence of giant planets in between. Our enlargement and improvement of long-period planet parameters will aid future analysis of origins, diversity, and evolution of planetary systems.

  6. CONDITIONS OF PASSAGE AND ENTRAPMENT OF TERRESTRIAL PLANETS IN SPIN-ORBIT RESONANCES

    SciTech Connect

    Makarov, Valeri V.

    2012-06-10

    The dynamical evolution of terrestrial planets resembling Mercury in the vicinity of spin-orbit resonances is investigated using comprehensive harmonic expansions of the tidal torque taking into account the frequency-dependent quality factors and Love numbers. The torque equations are integrated numerically with a small step in time, including the oscillating triaxial torque components but neglecting the layered structure of the planet and assuming a zero obliquity. We find that a Mercury-like planet with a current value of orbital eccentricity (0.2056) is always captured in 3:2 resonance. The probability of capture in the higher 2:1 resonance is approximately 0.23. These results are confirmed by a semi-analytical estimation of capture probabilities as functions of eccentricity for both prograde and retrograde evolutions of spin rate. As follows from analysis of equilibrium torques, entrapment in 3:2 resonance is inevitable at eccentricities between 0.2 and 0.41. Considering the phase space parameters at the times of periastron, the range of spin rates and phase angles for which an immediate resonance passage is triggered is very narrow, and yet a planet like Mercury rarely fails to align itself into this state of unstable equilibrium before it traverses 2:1 resonance.

  7. On Mercury's entrapment into the 3:2 spin-orbit resonance

    NASA Astrophysics Data System (ADS)

    Noyelles, Benoit; Frouard, J.; Makarov, V.; Efroimsky, M.

    2013-10-01

    The rotational dynamics of Mercury is a peculiar case in the Solar System, since it is a supersynchronous, 3:2 resonant state, with the spin period being 2/3 of the orbital one. While it is widely accepted that the significant eccentricity (0.206) favours this configuration, the history of Mercury's despinning remains nonetheless a matter of discussion. At least three scenarios can be found in the scientific literature. The first one considers a homogeneous Mercury that was trapped after several crossings of the resonance, these crossings made possible by the chaotic evolution of the eccentricity (Correia & Laskar 2004). The second scenario includes friction at the core-mantle boundary, which increases the probabilities of capture during one crossing (Peale & Boss 1977, Correia & Laskar 2009). The third scenario assumes that Mercury had had a retrograde rotation, then a synchronous one, and only later came into the current 3:2 resonance. We here use a realistic model of tides, based on the Darwin-Kaula expansions combined with both the elastic rebound and anelastic creep of solids. Within this model, we find that the 3:2 spin-orbit resonance is the most probable for a homogeneous Mercury. Moreover, we find that leaving a resonance after being trapped is impossible or virtually impossible, thus excluding the possibility of a past 2:1 resonance. This also indicates that entrapment is likely to happen before the differentiation of Mercury takes place.

  8. Finite amplitude method applied to the giant dipole resonance in heavy rare-earth nuclei

    NASA Astrophysics Data System (ADS)

    Oishi, Tomohiro; Kortelainen, Markus; Hinohara, Nobuo

    2016-03-01

    Background: The quasiparticle random phase approximation (QRPA), within the framework of nuclear density functional theory (DFT), has been a standard tool to access the collective excitations of atomic nuclei. Recently, the finite amplitude method (FAM) was developed in order to perform the QRPA calculations efficiently without any truncation on the two-quasiparticle model space. Purpose: We discuss the nuclear giant dipole resonance (GDR) in heavy rare-earth isotopes, for which the conventional matrix diagonalization of the QRPA is numerically demanding. A role of the Thomas-Reiche-Kuhn (TRK) sum rule enhancement factor, connected to the isovector effective mass, is also investigated. Methods: The electric dipole photoabsorption cross section was calculated within a parallelized FAM-QRPA scheme. We employed the Skyrme energy density functional self-consistently in the DFT calculation for the ground states and FAM-QRPA calculation for the excitations. Results: The mean GDR frequency and width are mostly reproduced with the FAM-QRPA, when compared to experimental data, although some deficiency is observed with isotopes heavier than erbium. A role of the TRK enhancement factor in actual GDR strength is clearly shown: its increment leads to a shift of the GDR strength to higher-energy region, without a significant change in the transition amplitudes. Conclusions: The newly developed FAM-QRPA scheme shows remarkable efficiency, which enables one to perform systematic analysis of GDR for heavy rare-earth nuclei. The theoretical deficiency of the photoabsorption cross section could not be improved by only adjusting the TRK enhancement factor, suggesting the necessity of an approach beyond self-consistent QRPA and/or a more systematic optimization of the energy density functional (EDF) parameters.

  9. Onset of quenching of the giant dipole resonance at high excitation energies

    NASA Astrophysics Data System (ADS)

    Santonocito, D.; Blumenfeld, Y.; Agodi, C.; Alba, R.; Bellia, G.; Coniglione, R.; Delaunay, F.; Del Zoppo, A.; Finocchiaro, P.; Hongmei, F.; Lima, V.; Maiolino, C.; Migneco, E.; Piattelli, P.; Sapienza, P.; Scarpaci, J. A.; Wieland, O.

    2014-11-01

    The evolution of the giant dipole resonance (GDR) properties in nuclei of mass A =120 to 132 has been investigated in an excitation energy range between 150 and 270 MeV through the study of complete and nearly complete fusion reactions using 116Sn beams at 17 A and 23 A MeV from the cyclotron of the Laboratorio Nazionale del Sud impinging on 12C and 24Mg targets. γ rays and light charged particles were detected using the multi-element detector array MEDEA in coincidence with evaporation residues detected by using mass and charge identification spectrometry with telescope (MACISTE). Light-charged-particle energy spectra were analyzed within the framework of a multiple-source-emission scenario by using a fitting procedure to determine the amount of pre-equilibrium emission and deduce the excitation energies reached in the compound nuclei. A detailed analysis of the γ -ray spectra and their comparison with statistical model calculations is presented. Evidence of a quenching of the GDR gamma yield was found at 270 MeV excitation energy. The quenching effect becomes progressively more important with increasing excitation energy, as observed when the comparison is extended to data from the reaction 36Ar+96Mo at 37 A MeV where hot nuclei were populated up to 430 MeV excitation energy. A coherent scenario emerges indicating the existence of a limiting excitation energy for the collective motion of about E*/A =2.1 MeV for systems of mass A =105 to 111 while a slightly lower value was observed for nuclei of mass A ˜132 . The existence of a possible link between GDR disappearance and the liquid-gas phase transition is discussed.

  10. Dipole-Strength Distributions up to the Giant Dipole Resonance Deduced from Photon Scattering

    NASA Astrophysics Data System (ADS)

    Schwengner, R.; Rusev, G.; Benouaret, N.; Beyer, R.; Dönau, F.; Erhard, M.; Grosse, E.; Junghans, A. R.; Kosev, K.; Klug, J.; Nair, C.; Nankov, N.; Schilling, K. D.; Wagner, A.

    2008-04-01

    Dipole-strength distributions up to the neutron-separation energies of the even-mass Mo isotopes from 92Mo to 100Mo and of the N = 50 isotones 88Sr, 89Y, 90Zr have been investigated in photon-scattering experiments using the bremsstrahlung facility at the superconducting electron accelerator ELBE of the Forschungszentrum Dresden-Rossendorf. A measurement using polarised bremsstrahlung impinging on 88Sr revealed that all resolved transitions with energies greater than 6 MeV in this nuclide except for one are E1 transitions. The intensity distributions obtained from the measured spectra after a correction for detector response and a subtraction of atomic background in the target contain a continuum part in addition to the resolved peaks. It turns out that the dipole strength in the resolved peaks amounts to about 30% of the total dipole strength while the continuum contains about 70%. In order to estimate the distribution of inelastic transitions and to correct the ground-state transitions for their branching ratios simulations of γ-ray cascades were performed. The photoabsorption cross sections obtained in this way connect smoothly to (γ, n) cross sections and give novel information about the strength on the low-energy tails of the Giant Dipole Resonances below the neutron-separation energies. The experimental cross sections are compared with predictions of a Quasiparticle-Random-Phase Approximation in a deformed basis. The calculations describe the experimentally observed increase of the dipole strengths with increasing neutron number of the Mo isotopes as a consequence of increasing nuclear deformation.

  11. Global investigation of the fine structure of the isoscalar giant quadrupole resonance

    SciTech Connect

    Shevchenko, A.; Burda, O.; Kalmykov, Y.; Neumann-Cosel, P. von; Ponomarev, V. Yu.; Richter, A.; Wambach, J.; Carter, J.; Sideras-Haddad, E.; Cooper, G. R. J.; Fearick, R. W.; Foertsch, S. V.; Lawrie, J. J.; Neveling, R.; Smit, F. D.; Fujita, H.; Fujita, Y.; Lacroix, D.

    2009-04-15

    Fine structure in the region of the isoscalar giant quadrupole resonance (ISGQR) in {sup 58}Ni, {sup 89}Y, {sup 90}Zr, {sup 120}Sn, {sup 166}Er, and {sup 208}Pb has been observed in high-energy-resolution ({delta}E{sub 1/2}{approx_equal}35-50 keV) inelastic proton scattering measurements at E{sub 0}=200 MeV at iThemba LABS. Calculations of the corresponding quadrupole excitation strength functions performed within models based on the random-phase approximation (RPA) reveal similar fine structure when the mixing of one-particle one-hole states with two-particle two-hole states is taken into account. A detailed comparison of the experimental data is made with results from the quasiparticle-phonon model (QPM) and the extended time-dependent Hartree-Fock (ETDHF) method. For {sup 208}Pb, additional theoretical results from second RPA and the extended theory of finite Fermi systems (ETFFS) are discussed. A continuous wavelet analysis of the experimental and the calculated spectra is used to extract dominant scales characterizing the fine structure. Although the calculations agree with qualitative features of these scales, considerable differences are found between the model and experimental results and amongst different models. Within the framework of the QPM and ETDHF calculations it is possible to decompose the model spaces into subspaces approximately corresponding to different damping mechanisms. It is demonstrated that characteristic scales mainly arise from the collective coupling of the ISGQR to low-energy surface vibrations.

  12. Isoscalar monopole and dipole excitations of cluster states and giant resonances in 12C

    NASA Astrophysics Data System (ADS)

    Kanada-En'yo, Yoshiko

    2016-05-01

    The isoscalar monopole (ISM) and dipole (ISD) excitations in 12C are investigated theoretically with the shifted antisymmetrized molecular dynamics (AMD) plus 3 α -cluster generator coordinate method (GCM). The small-amplitude vibration modes are described by coherent one-particle one-hole excitations expressed by a small shift of single-nucleon Gaussian wave functions within the AMD framework, whereas the large-amplitude cluster modes are incorporated by superposing 3 α -cluster wave functions in the GCM. The coupling of the excitations in the intrinsic frame with the rotation and parity transformation is taken into account microscopically by the angular-momentum and parity projections. The present a calculation that describes the ISM and ISD excitations over a wide energy region covering cluster modes in the low-energy region and the giant resonances in the high-energy region, although the quantitative description of the high-energy part is not satisfactory. The low-energy ISM and ISD strengths of the cluster modes are enhanced by the distance motion between α clusters, and they split into a couple of states because of the angular motion of α clusters. The low-energy ISM strengths exhaust 26% of the energy-weighted sum rule, which is consistent with the experimental data for the 12C(02+; 7.65 MeV) and 12C(03+; 10.3 MeV) measured by (e ,e') ,(α ,α') , and (6Li,6Li' ) scatterings. In the calculated low-energy ISD strengths, two 1- states (the 11- and 12- states) with the significant strengths are obtained over E =10 -15 MeV. The results indicate that the ISD excitations can be a good probe to experimentally search for new cluster states such as the 12C(12-) obtained in the present calculation.

  13. Transport at spin-orbit and exchange-split interfaces and universal giant asymmetry (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Dang, Huong Thi; Jaffrès, Henri; Nguyen, T. L. Hoai; Drouhin, Henri-Jean

    2015-09-01

    We report on theoretical investigations and k.p calculations of carrier tunneling, both electrons and holes, in model systems and heterostructures composed of exchange-split III-V semiconductors, involving spin-orbit interactions. The two media are separated-or not-by a thin tunnel barrier made out of a (III-V) semiconductor. In a 2x2 exchange-split band model, we show that, when Dresselhaus interactions are included in the conduction band of two exchange-split semiconductors in contact in the antiparallel states of magnetization, the electrons are differently transmitted with respect to an axis orthogonal to both normal axis of the interface and of the magnetization. The transmission asymmetry (A) between +k// and -k// incidence is shown to be maximal (A=100%) at some points of the Brillouin zone corresponding to a totally quenched transmission at some given incidence angles. More generally, we derive a universal character of the transmission asymmetry A vs. the in-plane incidence wavevector, the reduced kinetic energy and exchange parameter, A being universally scaled by a unique function, independent of the spin-orbit strength and of material parameters. This particular asymmetry feature is reproduced by a more complete 14x14 band model involving coupling with the conduction band. On the other hand, calculations performed in the valence-band of equivalent model heterostructures and including tunnel barriers in both 6x6 (without inversion) and 14x14 k.p band model more astonishingly highlight, the same trends in the transmission asymmetry (A) which is related to the difference of orbital chirality and to the related branching (overlap) of the corresponding evanescent wavefunctions responsible for tunneling current. In both cases of electrons and holes, the asymmetry appears to be robust and persists only when a single electrode is magnetic.

  14. Kepler-539: A young extrasolar system with two giant planets on wide orbits and in gravitational interaction

    NASA Astrophysics Data System (ADS)

    Mancini, L.; Lillo-Box, J.; Southworth, J.; Borsato, L.; Gandolfi, D.; Ciceri, S.; Barrado, D.; Brahm, R.; Henning, Th.

    2016-05-01

    We confirm the planetary nature of Kepler-539 b (aka Kepler object of interest K00372.01), a giant transiting exoplanet orbiting a solar-analogue G2 V star. The mass of Kepler-539 b was accurately derived thanks to a series of precise radial velocity measurements obtained with the CAFE spectrograph mounted on the CAHA 2.2-m telescope. A simultaneous fit of the radial-velocity data and Kepler photometry revealed that Kepler-539 b is a dense Jupiter-like planet with a mass of Mp = 0.97 ± 0.29 MJup and a radius of Rp = 0.747 ± 0.018 RJup, making a complete circular revolution around its parent star in 125.6 days. The semi-major axis of the orbit is roughly 0.5 au, implying that the planet is at ≈0.45 au from the habitable zone. By analysing the mid-transit times of the 12 transit events of Kepler-539 b recorded by the Kepler spacecraft, we found a clear modulated transit time variation (TTV), which is attributable to the presence of a planet c in a wider orbit. The few timings available do not allow us to precisely estimate the properties of Kepler-539 c and our analysis suggests that it has a mass between 1.2 and 3.6 MJup, revolving on a very eccentric orbit (0.4

  15. Asymmetric orbital distribution near mean motion resonance: Application to planets observed by Kepler and radial velocities

    SciTech Connect

    Xie, Ji-Wei E-mail: jwxie@astro.utoronto.ca

    2014-05-10

    Many multiple-planet systems have been found by the Kepler transit survey and various radial velocity (RV) surveys. Kepler planets show an asymmetric feature, namely, there are small but significant deficits/excesses of planet pairs with orbital period spacing slightly narrow/wide of the exact resonance, particularly near the first order mean motion resonance (MMR), such as 2:1 and 3:2 MMR. Similarly, if not exactly the same, an asymmetric feature (pileup wide of 2:1 MMR) is also seen in RV planets, but only for massive ones. We analytically and numerically study planets' orbital evolutions near and in the MMR. We find that their orbital period ratios could be asymmetrically distributed around the MMR center regardless of dissipation. In the case of no dissipation, Kepler planets' asymmetric orbital distribution could be partly reproduced for 3:2 MMR but not for 2:1 MMR, implying that dissipation might be more important to the latter. The pileup of massive RV planets just wide of 2:1 MMR is found to be consistent with the scenario that planets formed separately then migrated toward the MMR. The location of the pileup infers a K value of 1-100 on the order of magnitude for massive planets, where K is the damping rate ratio between orbital eccentricity and semimajor axis during planet migration.

  16. Searching for Resonant Orbits in the 2001 SN263 Triple Asteroid

    NASA Astrophysics Data System (ADS)

    Masago, Bruna; Prado, Antonio; Marins Chiaradia, Ana Paula

    The objective of this work is to search for internal and external orbits for a probe that will orbit the body Beta of the triple system of asteroids 2001 SN263. This system consists of a central body (Alpha) with 2.6 km in diameter and two smaller bodies (Beta and Gamma) with 0.78 km and 0.58 km in diameter, respectively. The smaller bodies describe orbits around the more massive one. With respect to the central body, the second body is in an orbit that has semi-major axis of 16.63 km and a period of 6.23 days, and the third body is in an orbit that has semi-major axis of 3.80 km and a period of 0.69 days. This work studies various orbits that a spacecraft could use around the main body in order to pass near Beta. The main body of the asteroid is Alpha, and Beta is the secondary body. The third body is the spacecraft, whose mass is considered negligible, This scenario is called Alpha-Beta-Probe. A dynamic system is assumed where Beta describes Keplerian elliptical orbits. Their orbits are inclined around Alpha. It is considered that the gravitational forces of the three bodies and the flatness of the main body perturb the spacecraft orbit. This scenario is analyzed using the Precessing Inclined Bi-Elliptical problem. It is assumed a reference system centered on the main body and the reference plane is the one that contains the orbit of the second body. Furthermore, these orbits are assumed to precesses due to the presence of the flattening the main body (J2). Then, the argument of the periapsis (ω), the longitude of the ascending node (Ω) and longitude of periapsis (ϖ) are function of time. This work analyzed the spacecraft orbits regarding close approaches with the Beta. Analyzing the results, we concluded that any internal orbit is good enough to observe the system. However, the external orbits with resonances 1:3, 2:5, 3:8, 4:7 and 5:9 are the best choices to observe the secondary bodies without larger risks of collision.

  17. ORBITAL PHASE VARIATIONS OF THE ECCENTRIC GIANT PLANET HAT-P-2b

    SciTech Connect

    Lewis, Nikole K.; Showman, Adam P.; Knutson, Heather A.; Desert, Jean-Michel; Kao, Melodie; Cowan, Nicolas B.; Laughlin, Gregory; Fortney, Jonathan J.; Burrows, Adam; Bakos, Gaspar A.; Hartman, Joel D.; Deming, Drake; Crepp, Justin R.; Mighell, Kenneth J.; Agol, Eric; Charbonneau, David; Fischer, Debra A.; Hinkley, Sasha; Johnson, John Asher; Howard, Andrew W.; and others

    2013-04-01

    We present the first secondary eclipse and phase curve observations for the highly eccentric hot Jupiter HAT-P-2b in the 3.6, 4.5, 5.8, and 8.0 {mu}m bands of the Spitzer Space Telescope. The 3.6 and 4.5 {mu}m data sets span an entire orbital period of HAT-P-2b (P = 5.6334729 d), making them the longest continuous phase curve observations obtained to date and the first full-orbit observations of a planet with an eccentricity exceeding 0.2. We present an improved non-parametric method for removing the intrapixel sensitivity variations in Spitzer data at 3.6 and 4.5 {mu}m that robustly maps position-dependent flux variations. We find that the peak in planetary flux occurs at 4.39 {+-} 0.28, 5.84 {+-} 0.39, and 4.68 {+-} 0.37 hr after periapse passage with corresponding maxima in the planet/star flux ratio of 0.1138% {+-} 0.0089%, 0.1162% {+-} 0.0080%, and 0.1888% {+-} 0.0072% in the 3.6, 4.5, and 8.0 {mu}m bands, respectively. Our measured secondary eclipse depths of 0.0996% {+-} 0.0072%, 0.1031% {+-} 0.0061%, 0.071%{sub -0.013%}{sup +0.029,} and 0.1392% {+-} 0.0095% in the 3.6, 4.5, 5.8, and 8.0 {mu}m bands, respectively, indicate that the planet cools significantly from its peak temperature before we measure the dayside flux during secondary eclipse. We compare our measured secondary eclipse depths to the predictions from a one-dimensional radiative transfer model, which suggests the possible presence of a transient day side inversion in HAT-P-2b's atmosphere near periapse. We also derive improved estimates for the system parameters, including its mass, radius, and orbital ephemeris. Our simultaneous fit to the transit, secondary eclipse, and radial velocity data allows us to determine the eccentricity (e = 0.50910 {+-} 0.00048) and argument of periapse ({omega} = 188. Degree-Sign 09 {+-} 0. Degree-Sign 39) of HAT-P-2b's orbit with a greater precision than has been achieved for any other eccentric extrasolar planet. We also find evidence for a long-term linear

  18. Wake-body resonance of long flexible structures is dominated by counterclockwise orbits.

    PubMed

    Bourguet, Rémi; Modarres-Sadeghi, Yahya; Karniadakis, George E; Triantafyllou, Michael S

    2011-09-23

    We identify a dominant mechanism in the interaction between a slender flexible structure undergoing free vibrations in sheared cross-flow and the vortices forming in its wake: energy is transferred from the fluid to the body under a resonance condition, defined as wake-body frequency synchronization close to a natural frequency of the structure; this condition occurs within a well-defined region of the span, which is dominated by counterclockwise, figure-eight orbits. Clockwise orbits are associated with damping fluid forces. PMID:22026858

  19. The quest for companions to post-common envelope binaries. IV. The 2:1 mean-motion resonance of the planets orbiting NN Serpentis

    NASA Astrophysics Data System (ADS)

    Beuermann, K.; Dreizler, S.; Hessman, F. V.

    2013-07-01

    We present 69 new mid-eclipse times of the young post-common envelope binary (PCEB) NN Ser, which was previously suggested to possess two circumbinary planets. We have interpreted the observed eclipse-time variations in terms of the light-travel time effect caused by two planets, exhaustively covering the multi-dimensional parameter space by fits in the two binary and ten orbital parameters. We supplemented the fits by stability calculations for all models with an acceptable χ2. An island of secularly stable 2:1 resonant solutions exists, which coincides with the global χ2 minimum. Our best-fit stable solution yields current orbital periods Po = 15.47 yr and Pi = 7.65 yr and eccentricities eo = 0.14 and ei = 0.22 for the outer and inner planets, respectively. The companions qualify as giant planets, with masses of 7.0 MJup and 1.7 MJup for the case of orbits coplanar with that of the binary. The two-planet model that starts from the present system parameters has a lifetime greater than 108 yr, which significantly exceeds the age of NN Ser of 106 yr as a PCEB. The resonance is characterized by libration of the resonant variable Θ1 and circulation of , the difference between the arguments of periapse of the two planets. No stable nonresonant solutions were found, and the possibility of a 5:2 resonance suggested previously by us is now excluded at the 99.3% confidence level. Table 1 is available in electronic form at http://www.aanda.org

  20. Orbit-based analysis of resonant excitations of Alfvén waves in tokamaks

    SciTech Connect

    Bierwage, Andreas; Shinohara, Kouji

    2014-11-15

    The exponential growth phase of fast-ion-driven Alfvénic instabilities is simulated and the resonant wave-particle interactions are analyzed numerically. The simulations are carried out in realistic magnetic geometry and with a realistic particle distribution for a JT-60U plasma driven by negative-ion-based neutral beams. In order to deal with the large magnetic drifts of the fast ions, two new mapping methods are developed and applied. The first mapping yields the radii and pitch angles at the points, where the unperturbed orbit of a particle intersects the mid-plane. These canonical coordinates allow to express analysis results (e.g., drive profiles and resonance widths) in a form that is easy to understand and directly comparable to the radial mode structure. The second mapping yields the structure of the wave field along the particle trajectory. This allows us to unify resonance conditions for trapped and passing particles, determine which harmonics are driven, and which orders of the resonance are involved. This orbit-based resonance analysis (ORA) method is applied to fast-ion-driven instabilities with toroidal mode numbers n = 1-3. After determining the order and width of each resonance, the kinetic compression of resonant particles and the effect of linear resonance overlap are examined. On the basis of the ORA results, implications for the fully nonlinear regime, for the long-time evolution of the system in the presence of a fast ion source, and for the interpretation of experimental observations are discussed.

  1. Orbital clustering of distant Kuiper belt objects by hypothetical Planet 9. Secular or resonant?

    NASA Astrophysics Data System (ADS)

    Beust, H.

    2016-05-01

    Context. Statistical analysis of the orbits of distant Kuiper belt objects (KBOs) has led to the suggestion that an additional planet should reside in the solar system. According to recent models, the secular action of this body should cause orbital alignment of the KBOs. Aims: It was recently claimed that the KBOs affected by these dynamics are presumably trapped in mean-motion resonances with the suspected planet. I reinvestigate here the secular model underlying this idea. Methods: The original analysis was carried out by expanding and truncating the secular Hamiltonian. I show that this is inappropriate, as the series expansion is not convergent. I present a study based on numerical computation of the Hamiltonian with no expansion. Results: I show in phase-space diagrams the existence of apsidally anti-aligned, high eccentricity libration islands that were not present in the original modelling, but match numerical simulations. These island were claimed to correspond to bodies trapped in mean-motion resonances with the hypothetical planet and match the characteristics of the distant KBOs observed. Conclusions: My main result is that regular secular dynamics can account for the anti-aligned particles itself as well as mean-motion resonances. I also perform a semi-analytical study of resonant motion and show that some resonance are actually capable of producing the same libration islands. I then discuss the relative importance of both mechanisms.

  2. Orbital-plane precessional resonances for binary black-hole systems

    NASA Astrophysics Data System (ADS)

    Kesden, Michael; Zhao, Xinyu; Gerosa, Davide

    2016-03-01

    We derive a new class of post-Newtonian precessional resonances for binary black holes (BBHs) with misaligned spins. According to the orbit-averaged spin-precession equations, the angle between the orbital angular momentum L and the total angular momentum J oscillates with a period τ during which time L precesses about J by an angle α. If α is a rational multiple of 2 π, the precession of L will be closed indicating a resonance between the polar and azimuthal evolution of L . If α is an integer multiple of 2 π, the misalignment between the angular momentum ΔL radiated over the period τ and J will be minimized, as will the opening angle of the cone about which J precesses in an inertial frame. However, the direction of ΔL will remain nearly fixed in an inertial frame over many precessional periods, causing the direction of J to tilt as inspiraling BBHs pass through such a resonance. Generic BBHs encounter many such resonances during an inspiral from large separations. We derive the evolution of J near a resonance and assess their detectability by gravitational-wave detectors and astrophysical implications.

  3. The Homoclinic and Heteroclinic Connections of Planar Symmetric Resonant Orbits in the Restricted Three-Body Earth-Moon System

    NASA Astrophysics Data System (ADS)

    Peng, Chao

    2016-07-01

    This study presents planar symmetric resonant orbits in the restricted three-body Earth-Moon system and their homoclinic and heteroclinic connections in the vicinity of the Moon are analyzed in details. In the rotating coordinate frame of the circular restricted three-body problem, there exist planar periodic orbits that appear symmetric about the line connecting the Earth and the Moon. The orbital periods of these orbits demonstrate approximately p:q resonance with respect to the Moon (a spacecraft completes p orbits while the Moon completes q orbits around the Earth in the same time interval). For a specified resonant ratio, four cases of these symmetric resonant orbits (those with resonant ratios of 1:1, 1:2, 1:3, 2:1, 2:3, 3:1, 3:2, 3:4 are presented as examples) are defined and computed in the restricted three-body Earth-Moon system. We focus our attention on those resonant orbits that pass through the vicinity of the Moon and compute the corresponding stable and unstable invariant manifolds. Poincare maps are plotted by observing the orbital states of resonant orbits at perilunes and we then identify the presence of the homoclinic connection and the heteroclinic connection. This characteristic of orbital transfers might provide a means for observing the Moon's low-latitude regions with different longitudes and the insertion into lunar orbitis not necessary. Besides, other potential utilizations of the homoclinic and heteroclinic connections for fully making use of lunar gravity assist are also discussed.

  4. The theory of secondary resonances in the spin-orbit problem

    NASA Astrophysics Data System (ADS)

    Gkolias, Ioannis; Celletti, Alessandra; Efthymiopoulos, Christos; Pucacco, Giuseppe

    2016-06-01

    We study the resonant dynamics in a simple one degree of freedom, time dependent Hamiltonian model describing spin-orbit interactions. The equations of motion admit periodic solutions associated with resonant motions, the most important being the synchronous one in which most evolved satellites of the Solar system, including the Moon, are observed. Such primary resonances can be surrounded by a chain of smaller islands which one refers to as secondary resonances. Here, we propose a novel canonical normalization procedure allowing to obtain a higher order normal form, by which we obtain analytical results on the stability of the primary resonances as well as on the bifurcation thresholds of the secondary resonances. The procedure makes use of the expansion in a parameter, called the detuning, measuring the shift from the exact secondary resonance. Also, we implement the so-called `book-keeping' method, i.e. the introduction of a suitable separation of the terms in orders of smallness in the normal form construction, which deals simultaneously with all the small parameters of the problem. Our analytical computation of the bifurcation curves is in excellent agreement with the results obtained by a numerical integration of the equations of motion, thus providing relevant information on the parameter regions where satellites can be found in a stable configuration.

  5. YOUNG SOLAR SYSTEM's FIFTH GIANT PLANET?

    SciTech Connect

    Nesvorny, David

    2011-12-15

    Studies of solar system formation suggest that the solar system's giant planets formed and migrated in the protoplanetary disk to reach the resonant orbits with all planets inside {approx}15 AU from the Sun. After the gas disk's dispersal, Uranus and Neptune were likely scattered by the gas giants, and approached their current orbits while dispersing the transplanetary disk of planetesimals, whose remains survived to this time in the region known as the Kuiper Belt. Here we performed N-body integrations of the scattering phase between giant planets in an attempt to determine which initial states are plausible. We found that the dynamical simulations starting with a resonant system of four giant planets have a low success rate in matching the present orbits of giant planets and various other constraints (e.g., survival of the terrestrial planets). The dynamical evolution is typically too violent, if Jupiter and Saturn start in the 3:2 resonance, and leads to final systems with fewer than four planets. Several initial states stand out in that they show a relatively large likelihood of success in matching the constraints. Some of the statistically best results were obtained when assuming that the solar system initially had five giant planets and one ice giant, with the mass comparable to that of Uranus and Neptune, and which was ejected to interstellar space by Jupiter. This possibility appears to be conceivable in view of the recent discovery of a large number of free-floating planets in interstellar space, which indicates that planet ejection should be common.

  6. Role of deformation on giant resonances within the quasiparticle random-phase approximation and the Gogny force

    SciTech Connect

    Peru, S.; Goutte, H.

    2008-04-15

    Fully consistent axially-symmetric-deformed quasiparticle random phase approximation (QRPA) calculations have been performed, in which the same Gogny D1S effective force has been used for both the Hartree-Fock-Bogolyubov mean field and the QRPA approaches. Giant resonances calculated in deformed {sup 26-28}Si and {sup 22-24}Mg nuclei as well as in the spherical {sup 30}Si and {sup 28}Mg isotopes are presented. Theoretical results for isovector-dipole and isoscalar monopole, quadrupole, and octupole responses are presented and the impact of the intrinsic nuclear deformation is discussed.

  7. Measurement of the {sup 241}Am({gamma},n){sup 240}Am reaction in the giant dipole resonance region

    SciTech Connect

    Tonchev, A. P.; Howell, C. R.; Hutcheson, A.; Kwan, E.; Raut, R.; Rusev, G.; Tornow, W.; Hammond, S. L.; Huibregtse, C.; Kelley, J. H.; Kawano, T.; Vieira, D. J.; Wilhelmy, J. B.

    2010-11-15

    The photodisintegration cross section of the radioactive nucleus {sup 241}Am has been obtained using activation techniques and monoenergetic {gamma}-ray beams from the HI{gamma}S facility. The induced activity of {sup 240}Am produced via the {sup 241}Am({gamma},n) reaction was measured in the energy interval from 9 to 16 MeV utilizing high-resolution {gamma}-ray spectroscopy. The experimental data for the {sup 241}Am({gamma},n) reaction in the giant dipole resonance energy region are compared with statistical nuclear-model calculations.

  8. Photosynthetic potential of planets in 3 : 2 spin-orbit resonances

    NASA Astrophysics Data System (ADS)

    Brown, S. P.; Mead, A. J.; Forgan, D. H.; Raven, J. A.; Cockell, C. S.

    2014-10-01

    Photosynthetic life requires sufficient photosynthetically active radiation to metabolize. On Earth, plant behaviour, physiology and metabolism are sculpted around the night-day cycle by an endogenous biological circadian clock. The evolution of life was influenced by the Earth-Sun orbital dynamic, which generates the photo-environment incident on the planetary surface. In this work, the unusual photo-environment of an Earth-like planet (ELP) in 3 : 2 spin-orbit resonance is explored. Photo-environments on the ELP are longitudinally differentiated, in addition to differentiations related to latitude and depth (for aquatic organisms) which are familiar on Earth. The light environment on such a planet could be compatible with Earth's photosynthetic life although the threat of atmospheric freeze-out and prolonged periods of darkness would present significant challenges. We emphasize the relationship between the evolution of life on a planetary body with its orbital dynamics.

  9. Heteroclinic connections between periodic orbits and resonance transitions in celestial mechanics.

    PubMed

    Koon, Wang Sang; Lo, Martin W.; Marsden, Jerrold E.; Ross, Shane D.

    2000-06-01

    In this paper we apply dynamical systems techniques to the problem of heteroclinic connections and resonance transitions in the planar circular restricted three-body problem. These related phenomena have been of concern for some time in topics such as the capture of comets and asteroids and with the design of trajectories for space missions such as the Genesis Discovery Mission. The main new technical result in this paper is the numerical demonstration of the existence of a heteroclinic connection between pairs of periodic orbits: one around the libration point L(1) and the other around L(2), with the two periodic orbits having the same energy. This result is applied to the resonance transition problem and to the explicit numerical construction of interesting orbits with prescribed itineraries. The point of view developed in this paper is that the invariant manifold structures associated to L(1) and L(2) as well as the aforementioned heteroclinic connection are fundamental tools that can aid in understanding dynamical channels throughout the solar system as well as transport between the "interior" and "exterior" Hill's regions and other resonant phenomena. (c) 2000 American Institute of Physics. PMID:12779398

  10. Secular resonant dressed orbital diffusion - II. Application to an isolated self-similar tepid galactic disc

    NASA Astrophysics Data System (ADS)

    Fouvry, Jean-Baptiste; Pichon, Christophe

    2015-05-01

    The main orbital signatures of the secular evolution of an isolated self-gravitating stellar Mestel disc are recovered using a dressed Fokker-Planck formalism in angle-action variables. The shot-noise-driven formation of narrow ridges of resonant orbits is recovered in the WKB limit of tightly wound transient spirals, for a tepid Toomre-stable tapered disc. The relative effect of the bulge, the halo, the disc temperature and the spectral properties of the shot noise are investigated in turn. For such galactic discs all elements seem to impact the locus and direction of the ridge. For instance, when the halo mass is decreased, we observe a transition between a regime of heating in the inner regions of the disc through the inner Lindblad resonance to a regime of radial migration of quasi-circular orbits via the corotation resonance in the outer part of the disc. The dressed secular formalism captures both the nature of collisionless systems (via their natural frequencies and susceptibility), and their nurture via the structure of the external perturbing power spectrum. Hence it provides the ideal framework in which to study their long-term evolution.

  11. Which orbital and charge ordering in transition metal oxides can resonant X-ray diffraction detect?

    NASA Astrophysics Data System (ADS)

    Di Matteo, Sergio

    2009-11-01

    The present article is a brief critical review about the possibility of detecting charge and/or orbital order in transition-metal oxides by means of resonant x-ray diffraction. Many recent models of transition-metal oxides are based on charge and/or orbitally ordered ground-states and it has been claimed in the past that resonant x-ray diffraction is able to confirm or reject them. However, in spite of the many merits of this technique, such claims are ambiguous, because the interpretative frameworks used to analyze such results in transition-metal oxides, where structural distortions are always associated to the claimed charged/orbitally ordered transition, strongly influence (not to say suggest) the answer. In order to clarify this point, I discuss the two different definitions of orbital and charge orderings which are often used in the literature without a clear distinction. My conclusion is that the answer to the question of the title depends on which definition is adopted.

  12. WGM resonators for studying orbital angular momentum of a photon, and methods

    NASA Technical Reports Server (NTRS)

    Matsko, Andrey B. (Inventor); Savchenkov, Anatoliy A. (Inventor); Maleki, Lute (Inventor); Strekalov, Dmitry V. (Inventor)

    2009-01-01

    An optical system, device, and method that are capable of generating high-order Bessel beams and determining the orbital angular momentum of at least one of the photons of a Bessel beam are provided. The optical system and device include a tapered waveguide having an outer surface defined by a diameter that varies along a longitudinal axis of the waveguide from a first end to an opposing second end. The optical system and device include a resonator that is arranged in optical communication with the first end of the tapered waveguide such that an evanescent field emitted from (i) the waveguide can be coupled with the resonator, or (ii) the resonator can be coupled with the waveguide.

  13. Heavy ion Coulomb excitation and gamma decay studies of the one and two phonon giant dipole resonances in {sup 208}Pb and {sup 209}Bi

    SciTech Connect

    Mueller, P.E.; Beene, J.R.; Bertrand, F.E.

    1993-12-01

    Projectile -- photon coincidences were measured for the scattering of an 80 MeV/nucleon {sup 64}Zn beam from {sup 208}Pb and {sup 209}Bi targets at the GANIL heavy ion accelerator facility. Projectile-like particles between 0.5{degrees} and 4.5{degrees} relative to the incident beam direction were detected in the SPEG energy loss spectrometer where their momentum, charge, and mass were determined. Photons were detected in the BaF{sub 2} scintillation detector array TAPS. Light charged particles produced in the reaction were detected in the KVI Forward Wall. The analysis of the data acquired in this experiment is focused on three different phenomena: (1) the two phonon giant dipole resonance, (2) time dependence of the decay of the one phonon giant dipole resonance, and (3) giant resonance strength in projectile nuclei.

  14. Using Schumann Resonance Measurements for Constraining the Water Abundance on the Giant Planets—Implications for the Solar System's Formation

    NASA Astrophysics Data System (ADS)

    Simões, Fernando; Pfaff, Robert; Hamelin, Michel; Klenzing, Jeffrey; Freudenreich, Henry; Béghin, Christian; Berthelier, Jean-Jacques; Bromund, Kenneth; Grard, Rejean; Lebreton, Jean-Pierre; Martin, Steven; Rowland, Douglas; Sentman, Davis; Takahashi, Yukihiro; Yair, Yoav

    2012-05-01

    The formation and evolution of the solar system is closely related to the abundance of volatiles, namely water, ammonia, and methane in the protoplanetary disk. Accurate measurement of volatiles in the solar system is therefore important for understanding not only the nebular hypothesis and origin of life but also planetary cosmogony as a whole. In this work, we propose a new remote sensing technique to infer the outer planets' water content by measuring Tremendously and Extremely Low Frequency (TLF-ELF) electromagnetic wave characteristics (Schumann resonances) excited by lightning in their gaseous envelopes. Schumann resonance detection can be potentially used for constraining the uncertainty of volatiles of the giant planets, mainly Uranus and Neptune, because such TLF-ELF wave signatures are closely related to the electric conductivity profile and water content.

  15. Using Schumann Resonance Measurements for Constraining the Water Abundance on the Giant Planets - Implications for the Solar System Formation

    NASA Technical Reports Server (NTRS)

    Simoes, Fernando; Pfaff, Robert; Hamelin, Michel; Klenzing, Jeffrey; Freudenreich, Henry; Beghin, Christian; Berthelier, Jean-Jacques; Bromund, Kenneth; Grard, Rejean; Lebreton, Jean-Pierre; Martin, Steven; Rowland, Douglas; Sentman, Davis; Takahashi, Yukihiro; Yair, Yoav

    2012-01-01

    The formation and evolution of the Solar System is closely related to the abundance of volatiles, namely water, ammonia, and methane in the protoplanetary disk. Accurate measurement of volatiles in the Solar System is therefore important to understand not only the nebular hypothesis and origin of life but also planetary cosmogony as a whole. In this work, we propose a new, remote sensing technique to infer the outer planets water content by measuring Tremendously and Extremely Low Frequency (TLF-ELF) electromagnetic wave characteristics (Schumann resonances) excited by lightning in their gaseous envelopes. Schumann resonance detection can be potentially used for constraining the uncertainty of volatiles of the giant planets, mainly Uranus and Neptune, because such TLF-ELF wave signatures are closely related to the electric conductivity profile and water content.

  16. USING SCHUMANN RESONANCE MEASUREMENTS FOR CONSTRAINING THE WATER ABUNDANCE ON THE GIANT PLANETS-IMPLICATIONS FOR THE SOLAR SYSTEM'S FORMATION

    SciTech Connect

    Simoes, Fernando; Pfaff, Robert; Klenzing, Jeffrey; Freudenreich, Henry; Bromund, Kenneth; Martin, Steven; Rowland, Douglas; Takahashi, Yukihiro; Yair, Yoav

    2012-05-01

    The formation and evolution of the solar system is closely related to the abundance of volatiles, namely water, ammonia, and methane in the protoplanetary disk. Accurate measurement of volatiles in the solar system is therefore important for understanding not only the nebular hypothesis and origin of life but also planetary cosmogony as a whole. In this work, we propose a new remote sensing technique to infer the outer planets' water content by measuring Tremendously and Extremely Low Frequency (TLF-ELF) electromagnetic wave characteristics (Schumann resonances) excited by lightning in their gaseous envelopes. Schumann resonance detection can be potentially used for constraining the uncertainty of volatiles of the giant planets, mainly Uranus and Neptune, because such TLF-ELF wave signatures are closely related to the electric conductivity profile and water content.

  17. Hybrid DFT calculation of Fe57 NMR resonances and orbital order in magnetite

    NASA Astrophysics Data System (ADS)

    Patterson, C. H.

    2014-08-01

    The crystal structure and charge and orbital order of magnetite below the Verwey temperature are calculated using a first-principles hybrid density functional theory (DFT) method. The initial atomic positions in the crystal-structure calculation are those recently refined from x-ray diffraction data for the Cc space-group unit cell [Senn, Wright, and Attfield, Nature (London) 481, 173 (2012), 10.1038/nature10704]. Fermi contact and magnetic dipolar contributions to hyperfine fields at Fe57 nuclei obtained from hybrid DFT calculations are used to obtain NMR resonance frequencies for magnetite for a range of external magnetic field directions in a relatively weak field. NMR frequencies from hybrid density functional theory calculations are compared to NMR data [M. Mizoguchi, J. Phys. Soc. Jpn. 70, 2333 (2001), 10.1143/JPSJ.70.2333] for a range of applied magnetic field directions. NMR resonance frequencies of B-site Fe ions show large relative variations with applied field direction owing to anisotropic hyperfine fields from charge and orbital ordered Fe 3d minority-spin electrons at those sites. Good agreement between computed and measured NMR resonance frequencies confirms the pattern of charge and orbital order obtained from calculations. The charge and orbital order of magne-tite in its low-temperature phase obtained from hybrid DFT calculations is analyzed in terms of one-electron bonds between Fe ions. The Verwey transition in magnetite therefore resembles Mott-Peierls transitions in vanadium oxides which undergo symmetry-breaking transitions owing to electron-pair bond formation.

  18. Probing nuclear shapes close to the fission limit with the giant dipole resonance in {sup 216}Rn

    SciTech Connect

    Kmiecik, M.; Maj, A.; Brekiesz, M.; Krolas, W.; Meczynski, W.; Styczen, J.; Zieblinski, M.; Million, B.; Bracco, A.; Camera, F.; Benzoni, G.; Leoni, S.; Wieland, O.; Brambilla, S.; Herskind, B.; Kicinska-Habior, M.; Dubray, N.; Dudek, J.; Schunck, N.

    2004-12-01

    The gamma-ray decay of the giant dipole resonance (GDR) in the compound nucleus {sup 216}Rn formed with the reaction {sup 18}O+{sup 198}Pt at the bombarding energy of 96 MeV was investigated. High-energy gamma-ray spectra in coincidence with both prompt and delayed low-energy transitions were measured. The obtained GDR width at the average temperature {approx_equal}1 MeV was found to be larger than that at T=0 MeV and to be approximately constant as a function of spin. The measured width value of 7 MeV is found to be consistent with the predictions based on calculations of the nuclear shape distribution using the newest approach for the treatment of the fission barrier within the liquid drop model. The present study is the first investigation of the giant dipole resonance width from the fusion-evaporation decay channel in this nuclear mass range.

  19. Giant dipole resonance built on hot rotating nuclei produced during evaporation of light particles from the 88Mo compound nucleus

    NASA Astrophysics Data System (ADS)

    Ciemała, M.; Kmiecik, M.; Maj, A.; Mazurek, K.; Bracco, A.; Kravchuk, V. L.; Casini, G.; Barlini, S.; Baiocco, G.; Bardelli, L.; Bednarczyk, P.; Benzoni, G.; Bini, M.; Blasi, N.; Brambilla, S.; Bruno, M.; Camera, F.; Carboni, S.; Cinausero, M.; Chbihi, A.; Chiari, M.; Corsi, A.; Crespi, F. C. L.; D'Agostino, M.; Degerlier, M.; Fornal, B.; Giaz, A.; Gramegna, F.; Krzysiek, M.; Leoni, S.; Marchi, T.; Matejska-Minda, M.; Mazumdar, I.; Meczyński, W.; Million, B.; Montanari, D.; Morelli, L.; Myalski, S.; Nannini, A.; Nicolini, R.; Pasquali, G.; Piantelli, S.; Prete, G.; Roberts, O. J.; Schmitt, Ch.; Styczeń, J.; Szpak, B.; Valdré, S.; Wasilewska, B.; Wieland, O.; Wieleczko, J. P.; Ziebliński, M.; Dudek, J.; Dinh Dang, N.

    2015-05-01

    High-energy giant dipole resonance (GDR) γ rays were measured following the decay of the hot, rotating compound nucleus of 88Mo, produced at excitation energies of 124 and 261 MeV. The reaction 48Ti + 40Ca at 300 and 600 MeV bombarding energies has been used. The data were analyzed using the statistical model Monte Carlo code gemini++. It allowed extracting the giant dipole resonance parameters by fitting the high-energy γ -ray spectra. The extracted GDR widths were compared with the available data at lower excitation energy and with theoretical predictions based on (i) The Lublin-Strasbourg drop macroscopic model, supplemented with thermal shape fluctuations analysis, and (ii) The phonon damping model. The theoretical predictions were convoluted with the population matrices of evaporated nuclei from the statistical model gemini++. Also a comparison with the results of a phenomenological expression based on the existing systematics, mainly for lower temperature data, is presented and discussed. A possible onset of a saturation of the GDR width was observed around T =3 MeV.

  20. Roles of deformation and neutron excess on the giant monopole resonance in neutron-rich Zr isotopes

    SciTech Connect

    Yoshida, Kenichi

    2010-09-15

    We investigate the roles of deformation on the giant monopole resonance (GMR), particularly the mixing of the giant quadrupole resonance (GQR) and the effects of the neutron excess in the well-deformed nuclei around {sup 110}Zr and in the drip-line nuclei around {sup 140}Zr by means of the deformed quasiparticle-random-phase approximation employing the Skyrme and the local-pairing energy-density functionals. It is found that the isoscalar (IS) GMR has a two-peak structure, the lower peak of which is associated with the mixing between the ISGMR and the K{sup {pi}=}0{sup +} component of the ISGQR. The transition strength of the lower peak of the ISGMR grows as the neutron number increases. In the drip-line nuclei, the neutron excitation is dominant over the proton excitation. We find that for an isovector (IV) excitation the GMR has a four-peak structure due to the mixing of the IS and IV modes as well as the mixing of the K{sup {pi}=}0{sup +} component of the IVGQR. In addition to the GMR, we find that the threshold strength is generated by neutrons only.

  1. A KECK HIRES DOPPLER SEARCH FOR PLANETS ORBITING METAL-POOR DWARFS. II. ON THE FREQUENCY OF GIANT PLANETS IN THE METAL-POOR REGIME

    SciTech Connect

    Sozzetti, Alessandro; Torres, Guillermo; Latham, David W.; Stefanik, Robert P.; Korzennik, Sylvain G.; Boss, Alan P.; Carney, Bruce W.; Laird, John B. E-mail: gtorres@cfa.harvard.edu E-mail: skorzennik@cfa.harvard.edu E-mail: boss@dtm.ciw.edu E-mail: laird@bgsu.edu

    2009-05-20

    We present an analysis of three years of precision radial velocity (RV) measurements of 160 metal-poor stars observed with HIRES on the Keck 1 telescope. We report on variability and long-term velocity trends for each star in our sample. We identify several long-term, low-amplitude RV variables worthy of followup with direct imaging techniques. We place lower limits on the detectable companion mass as a function of orbital period. Our survey would have detected, with a 99.5% confidence level, over 95% of all companions on low-eccentricity orbits with velocity semiamplitude K {approx}> 100 m s{sup -1}, or M{sub p} sin i {approx}> 3.0 M {sub J}(P/yr){sup (1/3)}, for orbital periods P {approx}< 3 yr. None of the stars in our sample exhibits RV variations compatible with the presence of Jovian planets with periods shorter than the survey duration. The resulting average frequency of gas giants orbiting metal-poor dwarfs with -2.0{approx}<[Fe/H]{approx}<-0.6 is f{sub p} < 0.67% (at the 1{sigma} confidence level). We examine the implications of this null result in the context of the observed correlation between the rate of occurrence of giant planets and the metallicity of their main-sequence solar-type stellar hosts. By combining our data set with the Fischer and Valenti (2005) uniform sample, we confirm that the likelihood of a star to harbor a planet more massive than Jupiter within 2 AU is a steeply rising function of the host's metallicity. However, the data for stars with -1.0{approx}<[Fe/H]{approx}<0.0 are compatible, in a statistical sense, with a constant occurrence rate f{sub p} {approx_equal} 1%. Our results can usefully inform theoretical studies of the process of giant-planet formation across two orders of magnitude in metallicity.

  2. Fingerprints of entangled spin and orbital physics in itinerant ferromagnets via angle-resolved resonant photoemission

    NASA Astrophysics Data System (ADS)

    Da Pieve, F.

    2016-01-01

    A method for mapping the local spin and orbital nature of the ground state of a system via corresponding flip excitations is proposed based on angle-resolved resonant photoemission and related diffraction patterns, obtained here via an ab initio modified one-step theory of photoemission. The analysis is done on the paradigmatic weak itinerant ferromagnet bcc Fe, whose magnetism, a correlation phenomenon given by the coexistence of localized moments and itinerant electrons, and the observed non-Fermi-Liquid behavior at extreme conditions both remain unclear. The combined analysis of energy spectra and diffraction patterns offers a mapping of local pure spin-flip, entangled spin-flip-orbital-flip excitations and chiral transitions with vortexlike wave fronts of photoelectrons, depending on the valence orbital symmetry and the direction of the local magnetic moment. Such effects, mediated by the hole polarization, make resonant photoemission a promising tool to perform a full tomography of the local magnetic properties even in itinerant ferromagnets or macroscopically nonmagnetic systems.

  3. (. pi. sup +- ,. pi. sup +- prime N) reactions on sup 12 C and sup 208 Pb near the giant resonance region

    SciTech Connect

    Yoo, Sung Hoon.

    1990-05-01

    Angular distributions for the {sup 12}C({pi}{sup {plus minus}}, {pi}{sup {plus minus}}{prime} p) and {sup 208}Pb({pi}{sup {plus minus}}, {pi}{sup {plus minus}}{prime} p or n) reactions near the giant resonance region have been measured at T{sub {pi}} = 180 MeV, and found different between {pi}{sup +} and {pi}{sup {minus}} data. This observation is interpreted as evidence for different excitation mechanisms dominating the {pi}{sup {minus}}-nucleus and {pi}{sup +}-nucleus interactions in the giant resonance region of these targets. A comparison with the single-nucleon knock-out distorted-wave impulse approximation calculations shows, even though these calculations underestimate ({pi}{sup {plus minus}}, {pi}{sup {plus minus}}{prime} N) data for both targets, the dominance of direct process for ({pi}{sup +}, {pi}{sup {plus}}{prime} p) or ({pi}{sup {minus}}, {pi}{sup {minus}}{prime} n) in contrast to ({pi}{sup {minus}}, {pi}{sup {minus}}{prime} p) or ({pi}{sup +}, {pi}{sup +}{prime} n). In the ({pi}{sup +}, {pi}{sup +}{prime} p) reaction proton-proton hole states are excited directly and appear to have a large probability for direct decay with escape width, whereas in ({pi}{sup {minus}}, {pi}{sup {minus}}{prime} p) the preferentially excited neutron-neutron hole doorway states couple to resonance states and decay with spreading width. This interpretation led us to suggest that the ratio of cross-sections for inelastic scattering to the giant resonance region should be written in terms of an incoherent sum of cross-sections to neutron and proton doorway states. In a heavy nucleus such as {sup 208}Pb, neutron and proton doorway states. In a heavy nucleus such as {sup 208}Pb, neutron and proton doorway states contribute incoherently because the different decay processes do not populate the same final states of the residual nucleus.

  4. Homoclinic orbits and chaos in a pair of parametrically driven coupled nonlinear resonators.

    PubMed

    Kenig, Eyal; Tsarin, Yuriy A; Lifshitz, Ron

    2011-07-01

    We study the dynamics of a pair of parametrically driven coupled nonlinear mechanical resonators of the kind that is typically encountered in applications involving microelectromechanical systems (MEMS) and nanoelectromechanical systems (NEMS). We take advantage of the weak damping that characterizes these systems to perform a multiple-scales analysis and obtain amplitude equations, describing the slow dynamics of the system. This picture allows us to expose the existence of homoclinic orbits in the dynamics of the integrable part of the slow equations of motion. Using a version of the high-dimensional Melnikov approach, developed by G. Kovačič and S. Wiggins [Physica D 57, 185 (1992)], we are able to obtain explicit parameter values for which these orbits persist in the full system, consisting of both Hamiltonian and non-Hamiltonian perturbations, to form so-called Šilnikov orbits, indicating a loss of integrability and the existence of chaos. Our analytical calculations of Šilnikov orbits are confirmed numerically. PMID:21867278

  5. The effects of geopotential resonance on orbit determination for Landsat-4

    NASA Technical Reports Server (NTRS)

    Hoge, S. L.; Casteel, D. O.; Phenneger, M. C.; Smith, E. A.

    1988-01-01

    Analysis is presented demonstrating improved performance for Landsat-4 orbit determination using the Goddard Trajectory Determination System with an adjusted Goddard Earth Model-9 (GEM-9) for geopotential coefficients of the 15th degree and order. The orbital state is estimated along with the sine and cosine coefficients of degree and order 15, (C, S) sub 15,15. The estimates are made for two 5-day intervals of range and doppler data, primarily from the Tracking and Data Relay Satellite, during a period of low solar activity in January 1987. The average values of the estimated coefficients (C, S) sub 15,15 are used to modify the GEM-9 model, and orbit determination performance is tested on 17 consecutive 34-hour operational tracking data arcs in January 1987. Significant reductions in the mean values and standard deviations of the along-track position difference and the drag model scaling parameter from solution to solution are observed. The approach is guided by the shallow resonance theory of geopotential orbit perturbations.

  6. ON THE ORBITAL EVOLUTION OF A GIANT PLANET PAIR EMBEDDED IN A GASEOUS DISK. I. JUPITER-SATURN CONFIGURATION

    SciTech Connect

    Zhang Hui; Zhou Jilin

    2010-05-01

    We carry out a series of high-resolution (1024 x 1024) hydrodynamical simulations to investigate the orbital evolution of Jupiter and Saturn embedded in a gaseous protostellar disk. Our work extends the results in the classical papers of Masset and Snellgrove and Morbidelli and Crida by exploring various surface density profiles ({sigma}), where {sigma} {proportional_to} r {sup -{alpha}}. The stability of the mean motion resonances (MMRs) caused by the convergent migration of the two planets is studied as well. Our results show that (1) the gap formation process of Saturn is greatly delayed by the tidal perturbation of Jupiter. These perturbations cause inward or outward runaway migration of Saturn, depending on the density profiles on the disk. (2) The convergent migration rate increases as {alpha} increases and the type of MMRs depends on {alpha} as well. When 0 < {alpha} < 1, the convergent migration speed of Jupiter and Saturn is relatively slow, thus they are trapped into 2:1 MMR. When {alpha}>4/3, Saturn passes through the 2:1 MMR with Jupiter and is captured into the 3:2 MMR. (3) The 3:2 MMR turns out to be unstable when the eccentricity of Saturn (e{sub s} ) increases too high. The critical value above which instability will set in is e{sub s} {approx} 0.15. We also observe that the two planets are trapped into 2:1 MMR after the break of 3:2 MMR. This process may provide useful information for the formation of orbital configuration between Jupiter and Saturn in the solar system.

  7. Revisiting the capture of Mercury into its 3:2 spin-orbit resonance

    NASA Astrophysics Data System (ADS)

    Noyelles, Benoît; Frouard, Julien; Makarov, Valeri V.; Efroimsky, Michael

    2014-07-01

    We simulate the despinning of Mercury, with or without a fluid core, and with a frequency-dependent tidal model employed. The tidal model incorporates the viscoelastic (Maxwell) rebound at low frequencies and a predominantly inelastic (Andrade) creep at higher frequencies. It is combined with a statistically relevant set of histories of Mercury's eccentricity. The tidal model has a dramatic influence on the behaviour of spin histories near spin-orbit resonances. The probabilities of capture into high-order resonances are greatly enhanced. Exploring several scenarios, we conclude that the present 3:2 spin state was achieved by entrapment of an initially prograde cold Mercury when its age was less than 20 Myr, i.e., well before differentiation.

  8. Globular cluster scale sizes in giant galaxies: orbital anisotropy and tidally underfilling clusters in M87, NGC 1399 and NGC 5128

    NASA Astrophysics Data System (ADS)

    Webb, Jeremy J.; Sills, Alison; Harris, William E.; Gómez, Matías; Paolillo, Maurizio; Woodley, Kristin A.; Puzia, Thomas H.

    2016-08-01

    We investigate the shallow increase in globular cluster half-light radii with projected galactocentric distance Rgc observed in the giant galaxies M87, NGC 1399, and NGC 5128. To model the trend in each galaxy, we explore the effects of orbital anisotropy and tidally underfilling clusters. While a strong degeneracy exists between the two parameters, we use kinematic studies to help constrain the distance Rβ beyond which cluster orbits become anisotropic, as well as the distance Rfα beyond which clusters are tidally underfilling. For M87 we find Rβ > 27 kpc and 20 < Rfα < 40 kpc and for NGC 1399 Rβ > 13 kpc and 10 < Rfα < 30 kpc. The connection of Rfα with each galaxy's mass profile indicates the relationship between size and Rgc may be imposed at formation, with only inner clusters being tidally affected. The best-fitting models suggest the dynamical histories of brightest cluster galaxies yield similar present-day distributions of cluster properties. For NGC 5128, the central giant in a small galaxy group, we find Rβ > 5 kpc and Rfα > 30 kpc. While we cannot rule out a dependence on Rgc, NGC 5128 is well fitted by a tidally filling cluster population with an isotropic distribution of orbits, suggesting it may have formed via an initial fast accretion phase. Perturbations from the surrounding environment may also affect a galaxy's orbital anisotropy profile, as outer clusters in M87 and NGC 1399 have primarily radial orbits while outer NGC 5128 clusters remain isotropic.

  9. Mercury's capture into the 3/2 spin-orbit resonance including the effect of core-mantle friction

    NASA Astrophysics Data System (ADS)

    Correia, Alexandre C. M.; Laskar, Jacques

    2009-05-01

    The rotation of Mercury is presently captured in a 3/2 spin-orbit resonance with the orbital mean motion. The capture mechanism is well understood as the result of tidal interactions with the Sun combined with planetary perturbations [Goldreich, P., Peale, S., 1966. Astron. J. 71, 425-438; Correia, A.C.M., Laskar, J., 2004. Nature 429, 848-850]. However, it is now almost certain that Mercury has a liquid core [Margot, J.L., Peale, S.J., Jurgens, R.F., Slade, M.A., Holin, I.V., 2007. Science 316, 710-714] which should induce a contribution of viscous friction at the core-mantle boundary to the spin evolution. According to Peale and Boss [Peale, S.J., Boss, A.P., 1977. J. Geophys. Res. 82, 743-749] this last effect greatly increases the chances of capture in all spin-orbit resonances, being 100% for the 2/1 resonance, and thus preventing the planet from evolving to the presently observed configuration. Here we show that for a given resonance, as the chaotic evolution of Mercury's orbit can drive its eccentricity to very low values during the planet's history, any previous capture can be destabilized whenever the eccentricity becomes lower than a critical value. In our numerical integrations of 1000 orbits of Mercury over 4 Gyr, the spin ends 99.8% of the time captured in a spin-orbit resonance, in particular in one of the following three configurations: 5/2 (22%), 2/1 (32%) and 3/2 (26%). Although the present 3/2 spin-orbit resonance is not the most probable outcome, we also show that the capture probability in this resonance can be increased up to 55% or 73%, if the eccentricity of Mercury in the past has descended below the critical values 0.025 or 0.005, respectively.

  10. Chemical abundances and kinematics of 257 G-, K-type field giants. Setting a base for further analysis of giant-planet properties orbiting evolved stars

    NASA Astrophysics Data System (ADS)

    Adibekyan, V. Zh.; Benamati, L.; Santos, N. C.; Alves, S.; Lovis, C.; Udry, S.; Israelian, G.; Sousa, S. G.; Tsantaki, M.; Mortier, A.; Sozzetti, A.; De Medeiros, J. R.

    2015-06-01

    We performed a uniform and detailed abundance analysis of 12 refractory elements (Na, Mg, Al, Si, Ca, Ti, Cr, Ni, Co, Sc, Mn, and V) for a sample of 257 G- and K-type evolved stars from the CORALIE planet search programme. To date, only one of these stars is known to harbour a planetary companion. We aimed to characterize this large sample of evolved stars in terms of chemical abundances and kinematics, thus setting a solid base for further analysis of planetary properties around giant stars. This sample, being homogeneously analysed, can be used as a comparison sample for other planet-related studies, as well as for different type of studies related to stellar and Galaxy astrophysics. The abundances of the chemical elements were determined using an local thermodynamic equilibrium (LTE) abundance analysis relative to the Sun, with the spectral synthesis code MOOG and a grid of Kurucz ATLAS9 atmospheres. To separate the Galactic stellar populations, both a purely kinematical approach and a chemical method were applied. We confirm the overabundance of Na in giant stars compared to the field FGK dwarfs. This enhancement might have a stellar evolutionary character, but departures from LTE may also produce a similar enhancement. Our chemical separation of stellar populations also suggests a `gap' in metallicity between the thick-disc and high-α metal-rich stars, as previously observed in dwarfs sample from HARPS. The present sample, as most of the giant star samples, also suffers from the B - V colour cut-off, which excludes low-log g stars with high metallicities, and high-log g star with low [Fe/H]. For future studies of planet occurrence dependence on stellar metallicity around these evolved stars, we suggest to use a subsample of stars in a `cut-rectangle' in the log g-[Fe/H] diagram to overcome the aforementioned issue.

  11. Constraints on the neutron skin and symmetry energy from the anti-analog giant dipole resonance in 208Pb

    NASA Astrophysics Data System (ADS)

    Cao, Li-Gang; Roca-Maza, X.; Colò, G.; Sagawa, H.

    2015-09-01

    We investigate the impact of the neutron skin thickness, Δ Rn p , on the energy difference between the anti-analog giant dipole resonance (AGDR), EAGDR, and the isobaric analog state (IAS), EIAS, in a heavy nucleus such as 208Pb. For guidance, we first develop a simple and analytic, yet physical, approach based on the droplet model that linearly connects the energy difference EAGDR-EIAS with Δ Rn p . To test this correlation on more fundamental grounds, we employ a family of systematically varied Skyrme energy density functionals where variations on the value of the symmetry energy at saturation density J are explored. The calculations have been performed within the fully self-consistent Hartree-Fock (HF) plus charge-exchange random phase approximation (RPA) framework. We confirm the linear correlation within our microscopic approach and we can compare our results with available experimental data in 208Pb in order to extract a preferred value for Δ Rn p and, in turn, for the symmetry energy parameters. Averaging the results from two available experimental data, our analysis gives Δ Rn p = 0.236 ±0.018 fm, J = 33.2 ±1.0 MeV, and a slope parameter of the symmetry energy at saturation L = 97.3 ±11.2 MeV. The errors include the experimental uncertainties and a lower-limit estimate of model uncertainties. These results are consistent with those extracted from different experimental data albeit L and Δ Rn p are somewhat large when compared to previous estimations based on giant resonance studies. Possible hints whether model dependence can explain this difference are provided.

  12. Spin-orbit interaction in bent carbon nanotubes: resonant spin transitions

    NASA Astrophysics Data System (ADS)

    Osika, E. N.; Szafran, B.

    2015-11-01

    We develop an effective tight-binding Hamiltonian for spin-orbit (SO) interaction in bent carbon nanotubes (CNT) for the electrons forming the π bonds between the nearest neighbor atoms. We account for the bend of the CNT and the intrinsic spin-orbit interaction which introduce mixing of π and σ bonds between the p z orbitals along the CNT. The effect contributes to the main origin of the SO coupling—the folding of the graphene plane into the nanotube. We discuss the bend-related contribution of the SO coupling for resonant single-electron spin and charge transitions in a double quantum dot. We report that although the effect of the bend-related SO coupling is weak for the energy spectra, it produces a pronounced increase of the spin transition rates driven by an external electric field. We find that spin-flipping transitions driven by alternate electric fields have usually larger rates when accompanied by charge shift from one dot to the other. Spin-flipping transition rates are non-monotonic functions of the driving amplitude since they are masked by stronger spin-conserving charge transitions. We demonstrate that the fractional resonances—counterparts of multiphoton transitions for atoms in strong laser fields—occurring in electrically controlled nanodevices already at moderate ac amplitudes—can be used to maintain the spin-flip transitions.

  13. Semianalytical study of geosynchronous orbits about a precessing oblate earth under lunisolar gravitation and tesseral resonance

    NASA Astrophysics Data System (ADS)

    Belyanin, S.; Gurfil, P.

    2009-03-01

    Previous studies of geosynchronous orbits indicated that the equinoctial precession (EP) of the Earth affects the long-term behavior of geosynchronous satellites for missions exceeding ten years. However, these studies did not include the lunisolar gravitation and tesseral resonance. In the present study, a model that includes the latter effects is developed. In particular, it is shown that the EP affects motion in the vicinity of the stable and unstable geostationary points. This effect is pronounced in the vicinity of the unstable points, shifting the satellite away from the geosynchronous altitude. Moreover, it is shown that secular inclination growth on time scales of 10-20 years is induced by the EP. This requires additional stationkeeping maneuvers that may increase the overall fuel usage by about 1%. An additional contribution of the present study is an analysis of EP-perturbed orbits with free inclination drift. An optimal initial node location, minimizing the inclination drift, is calculated while taking into account the effect of the EP. It is shown that the classical optimal initial node locations are changed due to the effect of the EP. A maneuvering program in the presence of EP is developed. It is shown that the timing and number of stationkeeping maneuvers is affected by the EP. The models developed herein utilize non-singular orbital elements.

  14. Symmetric periodic orbits of the many-body problem. Resonance and parade of planets.

    NASA Astrophysics Data System (ADS)

    Tkhai, V. N.

    The motion of a mechanical system consisting of n+1 material points attracting one another according to Newton`s law is investigated. A reversible system of differential equations is derived for the motion of n points relative to the "main body". A small parameter is introduced. When this parameter is equated to zero, each of the n points is attracted by the "main body" only, and the generating system splits into n two-body problems. Two types of generating periodic orbits, symmetric about the fixed set M of an automorphism, are considered: (1) with both eccentricities and inclinations equal to zero; (2) with inclinations equal to zero. It is shown that such orbits can be continued to non-zero values of the small parameter, as a result of which the system has periodic solutions of the first and second kinds. All these orbits are resonant: the mean motions of the bodies relate to one another as integers. In addition, at times that are multiples of the half-period the bodies are situated along a straight line, thus forming a "parade of planets". The results also apply to a "Sun-planet-satellite" type system. In the general theoretical part of the paper two methods are proposed for solving the problem of extending symmetric periodic motions to non-zero parameter values, and an upper bound is estimated for the domain of continuability.

  15. Molecular Orbital Simulations of Metal 1s2p Resonant Inelastic X-ray Scattering.

    PubMed

    Guo, Meiyuan; Källman, Erik; Sørensen, Lasse Kragh; Delcey, Mickaël G; Pinjari, Rahul V; Lundberg, Marcus

    2016-07-28

    For first-row transition metals, high-resolution 3d electronic structure information can be obtained using resonant inelastic X-ray scattering (RIXS). In the hard X-ray region, a K pre-edge (1s→3d) excitation can be followed by monitoring the dipole-allowed Kα (2p→1s) or Kβ (3p→1s) emission, processes labeled 1s2p or 1s3p RIXS. Here the restricted active space (RAS) approach, which is a molecular orbital method, is used for the first time to study hard X-ray RIXS processes. This is achieved by including the two sets of core orbitals in different partitions of the active space. Transition intensities are calculated using both first- and second-order expansions of the wave vector, including, but not limited to, electric dipoles and quadrupoles. The accuracy of the approach is tested for 1s2p RIXS of iron hexacyanides [Fe(CN)6](n-) in ferrous and ferric oxidation states. RAS simulations accurately describe the multiplet structures and the role of 2p and 3d spin-orbit coupling on energies and selection rules. Compared to experiment, relative energies of the two [Fe(CN)6](3-) resonances deviate by 0.2 eV in both incident energy and energy transfer directions, and multiplet splittings in [Fe(CN)6](4-) are reproduced within 0.1 eV. These values are similar to what can be expected for valence excitations. The development opens the modeling of hard X-ray scattering processes for both solution catalysts and enzymatic systems. PMID:27398775

  16. The SOPHIE search for northern extrasolar planets. XI. Three new companions and an orbit update: Giant planets in the habitable zone

    NASA Astrophysics Data System (ADS)

    Díaz, R. F.; Rey, J.; Demangeon, O.; Hébrard, G.; Boisse, I.; Arnold, L.; Astudillo-Defru, N.; Beuzit, J.-L.; Bonfils, X.; Borgniet, S.; Bouchy, F.; Bourrier, V.; Courcol, B.; Deleuil, M.; Delfosse, X.; Ehrenreich, D.; Forveille, T.; Lagrange, A.-M.; Mayor, M.; Moutou, C.; Pepe, F.; Queloz, D.; Santerne, A.; Santos, N. C.; Sahlmann, J.; Ségransan, D.; Udry, S.; Wilson, P. A.

    2016-07-01

    We report the discovery of three new substellar companions to solar-type stars, HD 191806, HD 214823, and HD 221585, based on radial velocity measurements obtained at the Haute-Provence Observatory. Data from the SOPHIE spectrograph are combined with observations acquired with its predecessor, ELODIE, to detect and characterise the orbital parameters of three new gaseous giant and brown dwarf candidates. Additionally, we combine SOPHIE data with velocities obtained at the Lick Observatory to improve the parameters of an already known giant planet companion, HD 16175 b. Thanks to the use of different instruments, the data sets of all four targets span more than ten years. Zero-point offsets between instruments are dealt with using Bayesian priors to incorporate the information we possess on the SOPHIE/ELODIE offset based on previous studies. The reported companions have orbital periods between three and five years and minimum masses between 1.6 MJup and 19 MJup. Additionally, we find that the star HD 191806 is experiencing a secular acceleration of over 11 m s-1 per year, potentially due to an additional stellar or substellar companion. A search for the astrometric signature of these companions was carried out using Hipparcos data. No orbit was detected, but a significant upper limit to the companion mass can be set for HD 221585, whose companion must be substellar. With the exception of HD 191806 b, the companions are located within the habitable zone of their host star. Therefore, satellites orbiting these objects could be a propitious place for life to develop. Based on observations collected with the SOPHIE spectrograph on the 1.93-m telescope at Observatoire de Haute-Provence (CNRS), France by the SOPHIE Consortium (programme 07A.PNP.CONS to 15A.PNP.CONS).

  17. Studies of Pressure-Broadening of Alkali Atom Resonance Lines for Modeling Atmospheres of Extrasolar Giant Planets and Brown Dwarfs

    NASA Technical Reports Server (NTRS)

    Kirby, Kate; Babb, J.; Yoshino, K.

    2004-01-01

    In L-dwarfs and T-dwarfs the resonance lines of sodium and potassium are so profoundly pressure-broadened that their wings extend several hundred nanometers from line center. With accurate knowledge of the line profiles as a function of temperature and pressure: such lines can prove to be valuable diagnostics of the atmospheres of such objects. We have initiated a joint program of theoretical and experimental research to study the line-broadening of alkali atom resonance lines due to collisions with species such as helium and molecular hydrogen. Although potassium and sodium are the alkali species of most interest in the atmospheres of cool brown dwarfs and extrasolar giant planets, some of our theoretical focus this year has involved the calculation of pressure-broadening of lithium resonance lines by He, as a test of a newly developed suite of computer codes. In addition, theoretical calculations have been carried out to determine the leading long range van der Waals coefficients for the interactions of ground and excited alkali metal atoms with helium atoms, to within a probable error of 2%. Such data is important in determining the behavior of the resonance line profiles in the far wings. Important progress has been made on the experimental aspects of the program since the arrival of a postdoctoral fellow in September. A new absorption cell has been designed, which incorporates a number of technical improvements over the previous cell, including a larger cell diameter to enhance the signal, and fittings which allow for easier cleaning, thereby significantly reducing the instrument down-time.

  18. The orbital evolution of real asteroids near the 4:1 mean-motion resonance with Jupiter

    NASA Technical Reports Server (NTRS)

    Dahlgren, Mats; Hahn, Gerhard; Lagerkvist, C.-I.; Lundstroem, M.

    1992-01-01

    Numerical integrations of the orbits of ten asteroids with osculating elements near the 4:1 mean-motion resonance with Jupiter have been performed over 200,000 years into the future. A variety of orbital evolutions was found, depending on the start values of the semi-major axis. The orbit of asteroid 1983 RJ4, which lies almost exactly at the resonance center, experiences large variations in eccentricity, evolving into an Earth-crosser on a time-scale of a few 10(exp 4) years. This makes this region a potential source for Apollo objects and meteoritic material, although the width of the resonance region in semi-major axis seems to be very narrow.

  19. Description of the dipole giant resonance in heavy and superheavy nuclei within Skyrme random-phase approximation

    SciTech Connect

    Kleinig, W.; Nesterenko, V. O.; Kvasil, J.; Vesely, P.; Reinhard, P.-G.

    2008-10-15

    The E1(T=1) isovector dipole giant resonance (GDR) in heavy and superheavy deformed nuclei is analyzed over a sample of 18 rare-earth nuclei, four actinides, and three chains of superheavy elements (Z=102, 114, and 120). The basis of the description is the self-consistent separable random-phase approximation (SRPA) using the Skyrme force SLy6. The model well reproduces the experimental data in the rare-earth and actinide regions. The trend of the resonance peak energies follows the estimates from collective models, showing a bias to the volume mode for the rare-earth isotopes and a mix of volume and surface modes for actinides and superheavy elements. The widths of the GDR are mainly determined by the Landau fragmentation, which in turn is found to be strongly influenced by deformation. A deformation splitting of the GDR can contribute to about one-third of the width, and about 1 MeV further broadening can be associated with mechanisms beyond the SRPA description (e.g., escape widths and coupling with complex configurations)

  20. Atom Resonance Lines for Modeling Atmosphere: Studies of Pressure-Broadening of Alkali Atom Resonance Lines for Modeling Atmospheres of Extrasolar Giant Planets and Brown Dwarfs

    NASA Technical Reports Server (NTRS)

    Hasan, Hashima (Technical Monitor); Kirby, K.; Babb, J.; Yoshino, K.

    2005-01-01

    We report on progress made in a joint program of theoretical and experimental research to study the line-broadening of alkali atom resonance lines due to collisions with species such as helium and molecular hydrogen. Accurate knowledge of the line profiles of Na and K as a function of temperature and pressure will allow such lines to serve as valuable diagnostics of the atmospheres of brown dwarfs and extra-solar giant planets. A new experimental apparatus has been designed, built and tested over the past year, and we are poised to begin collecting data on the first system of interest, the potassium resonance lines perturbed by collisions with helium. On the theoretical front, calculations of line-broadening due to sodium collisions with helium are nearly complete, using accurate molecular potential energy curves and transition moments just recently computed for this system. In addition we have completed calculations of the three relevant potential energy curves and associated transition moments for K - He, using the MOLPRO quantum chemistry codes. Currently, calculations of the potential surfaces describing K-H2 are in progress.

  1. On turbulence driven by axial precession and tidal evolution of the spin-orbit angle of close-in giant planets

    NASA Astrophysics Data System (ADS)

    Barker, Adrian J.

    2016-08-01

    The spin axis of a rotationally deformed planet is forced to precess about its orbital angular momentum vector, due to the tidal gravity of its host star, if these directions are misaligned. This induces internal fluid motions inside the planet that are subject to a hydrodynamic instability. We study the turbulent damping of precessional fluid motions, as a result of this instability, in the simplest local computational model of a giant planet (or star), with and without a weak internal magnetic field. Our aim is to determine the outcome of this instability, and its importance in driving tidal evolution of the spin-orbit angle in precessing planets (and stars). We find that this instability produces turbulent dissipation that is sufficiently strong that it could drive significant tidal evolution of the spin-orbit angle for hot Jupiters with orbital periods shorter than about 10-18 days. If this mechanism acts in isolation, this evolution would be towards alignment or anti-alignment, depending on the initial angle, but the ultimate evolution (if other tidal mechanisms also contribute) is expected to be towards alignment. The turbulent dissipation is proportional to the cube of the precession frequency, so it leads to much slower damping of stellar spin-orbit angles, implying that this instability is unlikely to drive evolution of the spin-orbit angle in stars (either in planetary or close binary systems). We also find that the instability-driven flow can act as a system-scale dynamo, which may play a role in producing magnetic fields in short-period planets.

  2. On turbulence driven by axial precession and tidal evolution of the spin-orbit angle of close-in giant planets

    NASA Astrophysics Data System (ADS)

    Barker, Adrian J.

    2016-08-01

    The spin axis of a rotationally deformed planet is forced to precess about its orbital angular momentum vector, due to the tidal gravity of its host star, if these directions are misaligned. This induces internal fluid motions inside the planet that are subject to a hydrodynamic instability. We study the turbulent damping of precessional fluid motions, as a result of this instability, in the simplest local computational model of a giant planet (or star), with and without a weak internal magnetic field. Our aim is to determine the outcome of this instability, and its importance in driving tidal evolution of the spin-orbit angle in precessing planets (and stars). We find that this instability produces turbulent dissipation that is sufficiently strong that it could drive significant tidal evolution of the spin-orbit angle for hot Jupiters with orbital periods shorter than about 10-18 d. If this mechanism acts in isolation, this evolution would be towards alignment or anti-alignment, depending on the initial angle, but the ultimate evolution (if other tidal mechanisms also contribute) is expected to be towards alignment. The turbulent dissipation is proportional to the cube of the precession frequency, so it leads to much slower damping of stellar spin-orbit angles, implying that this instability is unlikely to drive evolution of the spin-orbit angle in stars (either in planetary or close binary systems). We also find that the instability-driven flow can act as a system-scale dynamo, which may play a role in producing magnetic fields in short-period planets.

  3. Mercury's capture into the 3/2 spin-orbit resonance as a result of its chaotic dynamics.

    PubMed

    Correia, Alexandre C M; Laskar, Jacques

    2004-06-24

    Mercury is locked into a 3/2 spin-orbit resonance where it rotates three times on its axis for every two orbits around the sun. The stability of this equilibrium state is well established, but our understanding of how this state initially arose remains unsatisfactory. Unless one uses an unrealistic tidal model with constant torques (which cannot account for the observed damping of the libration of the planet) the computed probability of capture into 3/2 resonance is very low (about 7 per cent). This led to the proposal that core-mantle friction may have increased the capture probability, but such a process requires very specific values of the core viscosity. Here we show that the chaotic evolution of Mercury's orbit can drive its eccentricity beyond 0.325 during the planet's history, which very efficiently leads to its capture into the 3/2 resonance. In our numerical integrations of 1,000 orbits of Mercury over 4 Gyr, capture into the 3/2 spin-orbit resonant state was the most probable final outcome of the planet's evolution, occurring 55.4 per cent of the time. PMID:15215857

  4. Drift resonance effect on stochastic runaway electron orbit in the presence of low-order magnetic perturbations

    NASA Astrophysics Data System (ADS)

    Matsuyama, A.; Yagi, M.; Kagei, Y.; Nakajima, N.

    2014-12-01

    During major disruptions, an induced loop voltage accelerates runaway electrons (REs) towards high energy, being in the order of 1-100 MeV in present tokamaks and ITER. The stochastization mechanisms of such high-energy RE drift orbits are investigated by three-dimensional (3D) orbit following in tokamak plasmas. Drift resonance is shown to play an important role in determining the onset of stochastic drift orbits for different electron energies, particularly in cases with low-order perturbations that have radially global eigenfunctions of the scale of the plasma minor radius. The drift resonance due to the coupling between the cross-field drift motion with radially global modes yields a secondary island structure in the RE drift orbit, where the width of the secondary drift islands shows a square-root dependence on the relativistic gamma factor γ. Only for highly relativistic REs (γ ≫ 1), the widths of secondary drift islands are comparable with those of magnetic islands due to the primary resonance, thus the stochastic threshold becoming sensitive to the RE energy. Because of poloidal asymmetry due to toroidicity, the threshold becomes sensitive not only to the relative amplitude but also to the phase difference between the modes. In this paper, some examples of 3D orbit-following calculations are presented for analytic models of magnetic perturbations with multiple toroidal mode numbers, for both possibilities that the drift resonance enhances and suppresses the stochastization being illustrated.

  5. Bodily tides near the 1:1 spin-orbit resonance: correction to Goldreich's dynamical model

    NASA Astrophysics Data System (ADS)

    Williams, James G.; Efroimsky, Michael

    2012-12-01

    Spin-orbit coupling is often described in an approach known as " the MacDonald torque", which has long become the textbook standard due to its apparent simplicity. Within this method, a concise expression for the additional tidal potential, derived by MacDonald (Rev Geophys 2:467-541, 1994), is combined with a convenient assumption that the quality factor Q is frequency-independent (or, equivalently, that the geometric lag angle is constant in time). This makes the treatment unphysical because MacDonald's derivation of the said formula was, very implicitly, based on keeping the time lag frequency-independent, which is equivalent to setting Q scale as the inverse tidal frequency. This contradiction requires the entire MacDonald treatment of both non-resonant and resonant rotation to be rewritten. The non-resonant case was reconsidered by Efroimsky and Williams (Cel Mech Dyn Astron 104:257-289, 2009), in application to spin modes distant from the major commensurabilities. In the current paper, we continue this work by introducing the necessary alterations into the MacDonald-torque-based model of falling into a 1-to-1 resonance. (The original version of this model was offered by Goldreich (Astron J 71:1-7, 1996). Although the MacDonald torque, both in its original formulation and in its corrected version, is incompatible with realistic rheologies of minerals and mantles, it remains a useful toy model, which enables one to obtain, in some situations, qualitatively meaningful results without resorting to the more rigorous (and complicated) theory of Darwin and Kaula. We first address this simplified model in application to an oblate primary body, with tides raised on it by an orbiting zero-inclination secondary. (Here the role of the tidally-perturbed primary can be played by a satellite, the perturbing secondary being its host planet. A planet may as well be the perturbed primary, its host star acting as the tide-raising secondary). We then extend the model to a

  6. Observation of Schumann Resonances in the Earth's Ionosphere: Implications for Thunderstorm and Lightning Monitoring from Orbit

    NASA Astrophysics Data System (ADS)

    Simoes, F.; Pfaff, R. F.; Bromund, K. R.; Freudenreich, H. T.; Holzworth, R. H.; Klenzing, J. H.; Liebrecht, M. C.; Martin, S.; Rowland, D. E.; Uribe, P.; Yokoyama, T.

    2011-12-01

    The Communications/Navigation Outage Forecasting System (C/NOFS) satellite investigates the electrodynamics of the equatorial regions using a low inclination (13°) orbit with perigee and apogee of 401 and 867 km, respectively. The satellite is equipped with a three-axis double probe electric field detector that provides continuous DC and AC electric field measurements, and two optical sensors for lightning detection. Among the most intriguing data acquired thus far, the electric field probe on C/NOFS unexpectedly detected Schumann resonances with amplitude up to ~1 μVm-1Hz-1/2 in the nightside ionosphere. We address these findings in the context of thunderstorms effects in the middle and upper atmosphere, namely implications for the global electric circuit dynamics and low frequency wave propagation.

  7. Secular resonances between bodies on close orbits: a case study of the Himalia prograde group of jovian irregular satellites

    NASA Astrophysics Data System (ADS)

    Li, Daohai; Christou, Apostolos A.

    2016-06-01

    The gravitational interaction between two objects on similar orbits can effect noticeable changes in the orbital evolution even if the ratio of their masses to that of the central body is vanishingly small. Christou (Icarus 174:215-229, 2005) observed an occasional resonant lock in the differential node Δ Ω between two members in the Himalia irregular satellite group of Jupiter in the N-body simulations (corresponding mass ratio ˜ 10^{-9}). Using a semianalytical approach, we have reproduced this phenomenon. We also demonstrate the existence of two additional types of resonance, involving angle differences Δ ω and Δ (Ω +π) between two group members. These resonances cause secular oscillations in eccentricity and/or inclination on timescales ˜ 1 Myr. We locate these resonances in ( a, e, i) space and analyse their topological structure. In subsequent N-body simulations, we confirm these three resonances and find a fourth one involving Δ π. In addition, we study the occurrence rates and the stability of the four resonances from a statistical perspective by integrating 1000 test particles for 100 Myr. We find ˜ 10 to 30 librators for each of the resonances. Particularly, the nodal resonance found by Christou is the most stable: 2 particles are observed to stay in libration for the entire integration.

  8. Spin orbit splitting of the photon induced Fano resonance in an oscillating graphene electrostatic barrier

    SciTech Connect

    Biswas, R.; Sinha, C.

    2014-04-07

    We investigate theoretically the effect of a time dependent oscillating potential on the transport property of the Dirac Fermion through a monolayer graphene electrostatic barrier under the influence of the Rashba spin orbit interaction. The time dependent problem is solved in the frame work of the non-perturbative Floquet approach. It is noted that the dynamic condition of the barrier may be controlled by tuning the Rashba parameter. Introduction of the spin orbit interaction causes splitting of the Fano resonance (FR), a characteristic feature in photon assisted tunneling. The separation between the spin split FR's gives an indirect measure of the fine structure of the quasi-hole bound state inside the barrier. The present findings on the Rashba splitting of the FR and its external control by tuning the oscillating field parameters might have potential for applications in spintronic devices, especially in the spin field effect transistors. The spin polarization of different Floquet sidebands is found to be quite sensitive to the spin-pseudospin interaction.

  9. The fragility of the terrestrial planets during a giant-planet instability

    NASA Astrophysics Data System (ADS)

    Kaib, Nathan A.; Chambers, John E.

    2016-02-01

    Many features of the outer Solar system are replicated in numerical simulations if the giant planets undergo an orbital instability that ejects one or more ice giants. During this instability, Jupiter and Saturn's orbits diverge, crossing their 2:1 mean motion resonance (MMR), and this resonance-crossing can excite the terrestrial planet orbits. Using a large ensemble of simulations of this giant-planet instability, we directly model the evolution of the terrestrial planet orbits during this process, paying special attention to systems that reproduce the basic features of the outer planets. In systems that retain four giant planets and finish with Jupiter and Saturn beyond their 2:1 MMR, we find at least an 85 per cent probability that at least one terrestrial planet is lost. Moreover, systems that manage to retain all four terrestrial planets often finish with terrestrial planet eccentricities and inclinations larger than the observed ones. There is less than a ˜5 per cent chance that the terrestrial planet orbits will have a level of excitation comparable to the observed orbits. If we factor in the probability that the outer planetary orbits are well replicated, we find a probability of 1 per cent or less that the orbital architectures of the inner and outer planets are simultaneously reproduced in the same system. These small probabilities raise the prospect that the giant-planet instability occurred before the terrestrial planets had formed. This scenario implies that the giant-planet instability is not the source of the Late Heavy Bombardment and that terrestrial planet formation finished with the giant planets in their modern configuration.

  10. Combined dielectric and plasmon resonance for giant enhancement of Raman scattering

    NASA Astrophysics Data System (ADS)

    Kukushkin, V. I.; Grishina, Ya. V.; Egorov, S. V.; Solov'ev, V. V.; Kukushkin, I. V.

    2016-04-01

    Combined dielectric/metal resonators for colossal enhancement of inelastic light scattering are developed and their properties are investigated. It is shown that a record enhancement factor of 2 × 108 can be obtained using these structures. The dielectric resonators are fabricated on Si/SiO2 substrates where periodic arrays of square 10- to 200-nm-high dielectric pillars are produced via electron-beam lithography and plasma etching. The lateral size a of the pillars varies between 50 and 1500 nm, and their period in the array is 2 a. To make a combined dielectric/metal resonator, a nanostructured layer of silver is deposited onto the fabricated periodic dielectric structure by thermal evaporation. It is established that, for a fixed height of the dielectric pillars, the Raman scattering enhancement factor experiences pronounced oscillations as a function of the period (and size) of the pillars. It is shown that these oscillations are determined by the modes of the dielectric resonator and governed by the relation between the excitation laser wavelength and the planar size of the dielectric pillars.

  11. Resonant tunneling between two-dimensional layers accounting for spin-orbit interaction

    NASA Astrophysics Data System (ADS)

    Rozhansky, I. V.; Averkiev, N. S.; Lähderanta, E.

    2016-05-01

    We present a theory of quantum tunneling between two-dimensional (2D) layers with Rashba and Dresselhaus spin-orbit interaction (SOI) in the layers. Accounting for SOI in the layers leads to a complex pattern in the tunneling characteristic with typical features corresponding to SOI energy. The resonant features strongly depend on the SOI parameters; for clear experimental observation the SOI characteristic energy should exceed the resonant broadening related to the particles' quantum lifetime in the layers. It appears that the experiments on hole tunneling are favorable to meet this criterion. We also consider a promising candidate for observing the effect, that is, p -doped SiGe strained heterostructures. As supported by our calculations, small adjustments of the parameters for experimentally studied AlGaAs/GaAs p -type quantum walls or designing a 2D-2D tunneling experiment for recently fabricated SiGe structures are very likely to reveal the SOI features in the 2D-2D tunneling.

  12. Indirect bonding mechanism for proximity-induced giant spin-orbit coupling in graphene-topological insulator van der Waals heterostructure

    NASA Astrophysics Data System (ADS)

    Rajput, Shivani; Li, Yaoyi; Weinert, Michael; Li, Lian

    We demonstrate proximity-induced spin-orbit coupling in graphene/topological insulator van der Waals (vdW) heterostructures fabricated by transferring chemical vapor deposited graphene onto Bi2Se3 film grown by molecular beam epitaxy. Using scanning tunneling microscopy/spectroscopy, we observe a spin-orbit splitting of the graphene Dirac states up to 80 meV, with a spatial variation of +/-20 meV due to the inherent lack of epitaxial relation in the graphene/Bi2Se3 vdW junction. Density functional theory calculations further reveal that this giant spin-orbit splitting of the graphene bands is a consequence of the orthogonalization requirement on the overlapping wave functions, rather than simple direct bonding at the interface. This revelation of an indirect bonding mechanism of the proximity effect will facilitate more effective engineering of desired properties in vdW heterostructures. This work is supported by the U.S. Department of Energy under Award DE-FG02-07ER46228.

  13. REFINING THE PARALLAX IN VISUAL DOUBLE STARS USING ORBITAL AND SPECTRAL DATA: APPLICATION TO THE SYSTEM OF THE K0 GIANTS, A 1808

    SciTech Connect

    Docobo, J. A.; Tamazian, V. S.; Andrade, M.; Melikian, N. D.; Karapetian, A. A. E-mail: oatamaz@usc.es E-mail: nmelikia@bao.sci.am

    2008-08-15

    In this paper, we show how Hipparcos parallaxes of distant visual binaries ({pi}{sub Hip} {approx}< 10 mas) can be refined. This is accomplished by using relevant orbital and spectral data. To this end, we study the pair of K0 giants, A 1808. A revised orbit of this system is presented that was calculated by taking into account a set of interferometric and visual measurements covering almost one orbital revolution. In addition, by analyzing its spectrum obtained with the 2.6 m telescope of the Byurakan Astrophysical Observatory (Armenia), we confirm the MK spectral type, K0III. On the basis of B - V photometric data, we derived the extinction A{sub V} = 0.23 {+-} 0.08 mag as well as obtained a spectroscopic parallax ({pi}{sub sp} = 3.19 {+-} 0.21 mas) with a much smaller relative uncertainty of 6.6% compared with that of Hipparcos (42.1%; {pi}{sub Hip} = 2.43 {+-} 1.00 mas). Accordingly, this system is now placed at 313 {+-} 21 pc. With the obtained spectroscopic parallax, a dynamical mass of 4.52{sup +1.24}{sub -0.90} M{sub sun} is obtained, which agrees well with that expected from standard calibrations.

  14. Calculations of the giant-dipole-resonance photoneutrons using a coupled EGS4-morse code

    SciTech Connect

    Liu, J.C.; Nelson, W.R.; Kase, K.R.; Mao, X.S.

    1995-10-01

    The production and transport of the photoneutrons from the giant-dipoleresonance reaction have been implemented in a coupled EGS4-MORSE code. The total neutron yield (including both the direct neutron and evaporation neutron components) is calculated by folding the photoneutron yield cross sections with the photon track length distribution in the target. Empirical algorithms based on the measurements have been developed to estimate the fraction and energy of the direct neutron component for each photon. The statistical theory in the EVAP4 code, incorporated as a MORSE subroutine, is used to determine the energies of the evaporation neutrons. These represent major improvements over other calculations that assumed no direct neutrons, a constant fraction of direct neutrons, monoenergetic direct neutron, or a constant nuclear temperature for the evaporation neutrons. It was also assumed that the slow neutrons (< 2.5 MeV) are emitted isotropically and the fast neutrons are emitted anisotropically in the form of 1+Csin{sup 2}{theta}, which have a peak emission at 900. Comparisons between the calculated and the measured photoneutron results (spectra of the direct, evaporation and total neutrons; nuclear temperatures; direct neutron fractions) for materials of lead, tungsten, tantalum and copper have been made. The results show that the empirical algorithms, albeit simple, can produce reasonable results over the interested photon energy range.

  15. Giant in-particle field concentration and Fano resonances at light scattering by high-refractive-index particles

    NASA Astrophysics Data System (ADS)

    Tribelsky, Michael I.; Miroshnichenko, Andrey E.

    2016-05-01

    We present the results of a detailed analytical study of light scattering by a particle with high refractive index m +i κ and low losses (m ≫1 ,0 <κ ≪1 ) based on the exact Mie solution. We show that there is a dramatic difference in the behavior of the electromagnetic field within the particle (inner problem) and outside it (outer problem). With an increase in m at fixed values of the other parameters, the field within the particle asymptotically converges to a periodic function of m . The electric and magnetic type Mie resonances of different orders overlap substantially. It may lead to a giant concentration of the electromagnetic energy within the particle. At the same time, we demonstrate that the solution for the outer problem makes it possible to present each partial scattered wave as a sum of two partitions. One of them corresponds to the m -independent wave, scattered by a perfectly reflecting particle and plays the role of a background, while the other is associated with the excitation of a sharply m -dependent resonant Mie mode. The interference of the partitions brings about a typical asymmetric Fano profile. The profile is obtained from the exact Mie solution by means of identical transformations without any additional assumptions and/or fitting. It makes it possible to generalize rigorously the Fano theory to the case of finite dissipation. At an increase in m the Fano resonances in the outer problem die out and the scattered field converges to the universal, m -independent profile. The behavior of the resonances at a fixed m and varying particle size parameter (x ) is also discussed in detail. The similarities and differences of the two cases (fixed x , varying m and fixed m , varying x ) are disclosed. We also show that under certain very general conditions the scattering cross section of a large lossy sphere cannot be smaller than half its geometric cross section, while its absorption cross section cannot exceed three halves of the geometric

  16. SUGGEL: A Program Suggesting the Orbital Angular Momentum of a Neutron Resonance from the Magnitude of its Neutron Width

    SciTech Connect

    Oh, S.Y.

    2001-02-02

    The SUGGEL computer code has been developed to suggest a value for the orbital angular momentum of a neutron resonance that is consistent with the magnitude of its neutron width. The suggestion is based on the probability that a resonance having a certain value of g{Gamma}{sub n} is an l-wave resonance. The probability is calculated by using Bayes' theorem on the conditional probability. The probability density functions (pdf's) of g{Gamma}{sub n} for up to d-wave (l=2) have been derived from the {chi}{sup 2} distribution of Porter and Thomas. The pdf's take two possible channel spins into account. This code is a tool which evaluators will use to construct resonance parameters and help to assign resonance spin. The use of this tool is expected to reduce time and effort in the evaluation procedure, since the number of repeated runs of the fitting code (e.g., SAMMY) may be reduced.

  17. Spin-helical Dirac states in graphene induced by polar-substrate surfaces with giant spin-orbit interaction: a new platform for spintronics

    PubMed Central

    Eremeev, S. V.; Nechaev, I. A.; Echenique, P. M.; Chulkov, E. V.

    2014-01-01

    Spintronics, or spin electronics, is aimed at efficient control and manipulation of spin degrees of freedom in electron systems. To comply with demands of nowaday spintronics, the studies of electron systems hosting giant spin-orbit-split electron states have become one of the most important problems providing us with a basis for desirable spintronics devices. In construction of such devices, it is also tempting to involve graphene, which has attracted great attention because of its unique and remarkable electronic properties and was recognized as a viable replacement for silicon in electronics. In this case, a challenging goal is to lift spin degeneracy of graphene Dirac states. Here, we propose a novel pathway to achieve this goal by means of coupling of graphene and polar-substrate surface states with giant Rashba-type spin-splitting. We theoretically demonstrate it by constructing the graphene@BiTeCl system, which appears to possess spin-helical graphene Dirac states caused by the strong interaction of Dirac and Rashba electrons. We anticipate that our findings will stimulate rapid growth in theoretical and experimental investigations of graphene Dirac states with real spin-momentum locking, which can revolutionize the graphene spintronics and become a reliable base for prospective spintronics applications. PMID:25365945

  18. Dipole-Strength Distributions Below the Giant Dipole Resonance in the Stable Even-Mass Molybdenum Isotopes

    SciTech Connect

    Rusev, G.; Hutcheson, A. L.; Kwan, E.; Tonchev, A. P.; Tornow, W.; Angell, C. T.; Hammond, S. L.; Kawowski, H. J.; Beyer, R.; Doenau, F.; Erhard, M.; Grosse, E.; Frauendorf, S.; Junghans, A. R.; Klug, J.; Kosev, K.; Nair, C.; Nikolov, N.; Schilling, K.-D.; Schwengner, R.

    2009-03-10

    Dipole-strength distributions in the stable even-mass molybdenum isotopes up to the neutron-separation energies have been studied in photon-scattering experiments with bremsstrahlung at the superconducting electron accelerator ELBE at the Research Center Dresden-Rossendorf, Germany, and with mono-energetic photon beams at the High Intensity Gamma-ray Source facility at Triangle Universities Nuclear Laboratory. In order to determine the dipole-strength distribution, statistical methods were developed for the analysis of the measured spectra. The data obtained for the stable even-mass molybdenum isotopes from the present ({gamma},{gamma}') experiments are combined with ({gamma},n) cross sections from the literature resulting in a photoabsorption cross section covering the full range from about 4 to 15 MeV, which is of interest for nuclear structure as well as for nuclear astrophysics network calculations. Novel information about the low-energy tail of the Giant Dipole Resonance and the energy spreading of its strength is derived.

  19. Dipole-Strength Distributions Below the Giant Dipole Resonance in the Stable Even-Mass Molybdenum Isotopes

    NASA Astrophysics Data System (ADS)

    Rusev, G.; Angell, C. T.; Beyer, R.; Dönau, F.; Erhard, M.; Grosse, E.; Hammond, S. L.; Hutcheson, A. L.; Frauendorf, S.; Junghans, A. R.; Kawowski, H. J.; Kelley, J. H.; Klug, J.; Kosev, K.; Kwan, E.; Nair, C.; Nikolov, N.; Schilling, K.-D.; Schwengner, R.; Tonchev, A. P.; Tornow, W.; Wagner, A.

    2009-03-01

    Dipole-strength distributions in the stable even-mass molybdenum isotopes up to the neutron-separation energies have been studied in photon-scattering experiments with bremsstrahlung at the superconducting electron accelerator ELBE at the Research Center Dresden-Rossendorf, Germany, and with mono-energetic photon beams at the High Intensity Gamma-ray Source facility at Triangle Universities Nuclear Laboratory. In order to determine the dipole-strength distribution, statistical methods were developed for the analysis of the measured spectra. The data obtained for the stable even-mass molybdenum isotopes from the present (γ,γ') experiments are combined with (γ,n) cross sections from the literature resulting in a photoabsorption cross section covering the full range from about 4 to 15 MeV, which is of interest for nuclear structure as well as for nuclear astrophysics network calculations. Novel information about the low-energy tail of the Giant Dipole Resonance and the energy spreading of its strength is derived.

  20. Giant Dipole Resonance in the hot and thermalized 132Ce nucleus: damping of collective modes at finite temperature

    SciTech Connect

    Wieland, O; Bracco, A; Camera, F; Benzoni, G; Blasi, N; Brambilla, S; Crespi, F; Giussani, A; Leoni, S; Million, B; Moroni, A; Barlini, S; Kravchuk, V L; Gramegna, F; Lanchais, A; Mastinu, P; Maj, A; Brekiesz, M; Kmiecik, M; Bruno, M; Geraci, E; Vannini, G; Casini, G; Chiari, M; Nannini, A; Ordine, A; Ormand, W E

    2006-06-16

    The {gamma} decay of the Giant Dipole Resonance in the {sup 132}Ce compound nucleus with temperature up to {approx} 4 MeV has been measured. The symmetric {sup 64}Ni + {sup 68}Zn at E{sub beam} = 300, 400, 500 MeV and the asymmetric reaction {sup 16}O + {sup 116}Sn at E{sub beam} = 130, 250 MeV have been investigated. Light charged particles and {gamma} rays have been detected in coincidence with the recoiling compound system. In the case of the mass symmetric {sup 64}Ni induced reaction the {gamma} and charged particle spectral shapes are found to be consistent with the emission from a fully equilibrated compound nuclei and the GDR parameters are extracted from the data using a statistical model analysis. The GDR width is found to increase almost linear with temperature. This increase is rather well reproduced within a model which includes both the thermal fluctuation of the nuclear shape and the lifetime of the compound nucleus.

  1. A DISK AROUND THE PLANETARY-MASS COMPANION GSC 06214-00210 b: CLUES ABOUT THE FORMATION OF GAS GIANTS ON WIDE ORBITS

    SciTech Connect

    Bowler, Brendan P.; Liu, Michael C.; Kraus, Adam L.; Mann, Andrew W.; Ireland, Michael J.

    2011-12-20

    We present Keck OSIRIS 1.1-1.8 {mu}m adaptive optics integral field spectroscopy of the planetary-mass companion to GSC 06214-00210, a member of the {approx}5 Myr Upper Scorpius OB association. We infer a spectral type of L0 {+-} 1, and our spectrum exhibits multiple signs of youth. The most notable feature is exceptionally strong Pa{beta} emission (EW = -11.4 {+-} 0.3 A), which signals the presence of a circumplanetary accretion disk. The luminosity of GSC 06214-00210 b combined with its age yields a model-dependent mass of 14 {+-} 2 M{sub Jup}, making it the lowest-mass companion to show evidence of a disk. With a projected separation of 320 AU, the formation of GSC 06214-00210 b and other very low mass companions on similarly wide orbits is unclear. One proposed mechanism is formation at close separations followed by planet-planet scattering to much larger orbits. Since that scenario involves a close encounter with another massive body, which is probably destructive to circumplanetary disks, it is unlikely that GSC 06214-00210 b underwent a scattering event in the past. This implies that planet-planet scattering is not solely responsible for the population of gas giants on wide orbits. More generally, the identification of disks around young planetary companions on wide orbits offers a novel method to constrain the formation pathway of these objects, which is otherwise notoriously difficult to do for individual systems. We also refine the spectral type of the primary from M1 to K7 and detect a mild (2{sigma}) excess at 22 {mu}m using Wide-Field Infrared Survey Explorer photometry.

  2. Two Transiting Earth-size Planets Near Resonance Orbiting a Nearby Cool Star

    NASA Astrophysics Data System (ADS)

    Petigura, Erik A.; Schlieder, Joshua E.; Crossfield, Ian J. M.; Howard, Andrew W.; Deck, Katherine M.; Ciardi, David R.; Sinukoff, Evan; Allers, Katelyn N.; Best, William M. J.; Liu, Michael C.; Beichman, Charles A.; Isaacson, Howard; Hansen, Brad M. S.; Lépine, Sébastien

    2015-10-01

    Discoveries from the prime Kepler mission demonstrated that small planets (<3 {R}\\oplus ) are common outcomes of planet formation. While Kepler detected many such planets, all but a handful orbit faint, distant stars and are not amenable to precise follow up measurements. Here, we report the discovery of two small planets transiting K2-21, a bright (K = 9.4) M0 dwarf located 65+/- 6 pc from Earth. We detected the transiting planets in photometry collected during Campaign 3 of NASA’s K2 mission. Analysis of transit light curves reveals that the planets have small radii compared to their host star, {R}P/{R}\\star = 2.60+/- 0.14% and 3.15+/- 0.20%, respectively. We obtained follow up NIR spectroscopy of K2-21 to constrain host star properties, which imply planet sizes of 1.59 ± 0.43 {R}\\oplus and 1.92 ± 0.53 {R}\\oplus , respectively, straddling the boundary between high-density, rocky planets and low-density planets with thick gaseous envelopes. The planets have orbital periods of 9.32414 days and 15.50120 days, respectively, and a period ratio {P}c/{P}b = 1.6624, very near to the 5:3 mean motion resonance, which may be a record of the system’s formation history. Transit timing variations due to gravitational interactions between the planets may be detectable using ground-based telescopes. Finally, this system offers a convenient laboratory for studying the bulk composition and atmospheric properties of small planets with low equilibrium temperatures.

  3. Kepler-432 b: a massive warm Jupiter in a 52-day eccentric orbit transiting a giant star

    NASA Astrophysics Data System (ADS)

    Ortiz, Mauricio; Gandolfi, Davide; Reffert, Sabine; Quirrenbach, Andreas; Deeg, Hans J.; Karjalainen, Raine; Montañés-Rodríguez, Pilar; Nespral, David; Nowak, Grzegorz; Osorio, Yeisson; Palle, Enric

    2015-01-01

    We study the Kepler object Kepler-432, an evolved star ascending the red giant branch. By deriving precise radial velocities from multi-epoch high-resolution spectra of Kepler-432 taken with the CAFE spectrograph at the 2.2 m telescope of Calar Alto Observatory and the FIES spectrograph at the Nordic Optical Telescope of Roque de Los Muchachos Observatory, we confirm the planetary nature of the object Kepler-432 b, which has a transit period of 52 days. We find a planetary mass of Mp = 5.84 ± 0.05MJup and a high eccentricity of e = 0.478 ± 0.004. With a semi-major axis of a = 0.303 ± 0.007 AU, Kepler-432 b is the first bona fide warm Jupiter detected to transit a giant star. We also find a radial velocity linear trend of γ˙ = 0.44 ± 0.04 m s-1 d-1, which suggests the presence of a third object in the system. Current models of planetary evolution in the post-main-sequence phase predict that Kepler-432 b will be most likely engulfed by its host star before the latter reaches the tip of the red giant branch. Based on observations collected at the German-Spanish Astronomical Center, Calar Alto, jointly operated by the Max-Planck-Institut für Astronomie (Heidelberg) and the Instituto de Astrofísica de Andalucía (IAA-CSIC, Granada).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 the Instituto de Astrofísica de Canarias.Table 3 is available in electronic form at http://www.aanda.org

  4. Orbit-based analysis of nonlinear energetic ion dynamics in tokamaks. I. Effective mode number profile and resonant frequency tracking

    NASA Astrophysics Data System (ADS)

    Bierwage, Andreas; Shinohara, Kouji

    2016-04-01

    The nonlinear interactions between shear Alfvén modes and tangentially injected beam ions in the 150-400 keV range are studied numerically in a JT-60U tokamak scenario with realistic geometry, large magnetic drifts, and strong beam drive. For this purpose, the recently developed orbit-based resonance analysis (ORA) method for circulating particles is extended, so that it can be applied to the nonlinear regime, where the spectrum of orbit-based poloidal mode numbers m orb varies in time as the fast ions undergo wave-particle trapping and radial transport. In particular, the extended ORA method captures the effect of nonlinear overlaps between resonances associated with neighboring harmonics ( m orb , n ) and ( m orb + 1 , n ) that cause long-distance ballistic transport. Two cases with low toroidal mode numbers n ≳ 1 are studied: an n = 1 mode without resonance overlap and a strongly driven n = 3 mode with resonance overlap. For both cases, an effective radial profile of the resonant poloidal mode number m res = M eff ( r ) is computed and used to track the effective resonant frequency ω res ( t ) of individual particles during their radial motion r(t). In Paper II, this frequency tracking technique will be applied to study the nonlinear frequency chirping and convective amplification of the modes.

  5. Generating giant and tunable nonlinearity in a macroscopic mechanical resonator from a single chemical bond

    PubMed Central

    Huang, Pu; Zhou, Jingwei; Zhang, Liang; Hou, Dong; Lin, Shaochun; Deng, Wen; Meng, Chao; Duan, Changkui; Ju, Chenyong; Zheng, Xiao; Xue, Fei; Du, Jiangfeng

    2016-01-01

    Nonlinearity in macroscopic mechanical systems may lead to abundant phenomena for fundamental studies and potential applications. However, it is difficult to generate nonlinearity due to the fact that macroscopic mechanical systems follow Hooke's law and respond linearly to external force, unless strong drive is used. Here we propose and experimentally realize high cubic nonlinear response in a macroscopic mechanical system by exploring the anharmonicity in chemical bonding interactions. We demonstrate the high tunability of nonlinear response by precisely controlling the chemical bonding interaction, and realize, at the single-bond limit, a cubic elastic constant of 1 × 1020 N m−3. This enables us to observe the resonator's vibrational bi-states transitions driven by the weak Brownian thermal noise at 6 K. This method can be flexibly applied to a variety of mechanical systems to improve nonlinear responses, and can be used, with further improvements, to explore macroscopic quantum mechanics. PMID:27225287

  6. Study of Collective Dipole Excitations below the Giant Dipole Resonance at HI{gamma}S

    SciTech Connect

    Tonchev, A. P.; Howell, C. R.; Tornow, W.; Angell, C.; Boswell, M.; Karwowski, H. J.; Chyzh, A.; Kelley, J. H.; Tsoneva, N.; Wu, Y. K.

    2007-02-26

    The High-Intensity Gamma-ray Source utilizing intra-cavity back-scattering of free electron laser photons from relativistic electrons allows one to produce a unique beam of high-flux gamma rays with 100% polarization and selectable energy and energy resolution which is ideal for low-energy {gamma}-ray scattering experiments. Nuclear resonance fluorescence experiments have been performed on N=82 nuclei. High sensitivity studies of E1 and M1 excitations at energies close to the neutron emission threshold have been performed. The method allows the determination of excitation energies, spin, parities, and decay branching ratios of the pygmy dipole mode of excitation. The observations are compared with calculations using statistical and quasi-particle random-phase approximations.

  7. Generating giant and tunable nonlinearity in a macroscopic mechanical resonator from a single chemical bond

    NASA Astrophysics Data System (ADS)

    Huang, Pu; Zhou, Jingwei; Zhang, Liang; Hou, Dong; Lin, Shaochun; Deng, Wen; Meng, Chao; Duan, Changkui; Ju, Chenyong; Zheng, Xiao; Xue, Fei; Du, Jiangfeng

    2016-05-01

    Nonlinearity in macroscopic mechanical systems may lead to abundant phenomena for fundamental studies and potential applications. However, it is difficult to generate nonlinearity due to the fact that macroscopic mechanical systems follow Hooke's law and respond linearly to external force, unless strong drive is used. Here we propose and experimentally realize high cubic nonlinear response in a macroscopic mechanical system by exploring the anharmonicity in chemical bonding interactions. We demonstrate the high tunability of nonlinear response by precisely controlling the chemical bonding interaction, and realize, at the single-bond limit, a cubic elastic constant of 1 × 1020 N m-3. This enables us to observe the resonator's vibrational bi-states transitions driven by the weak Brownian thermal noise at 6 K. This method can be flexibly applied to a variety of mechanical systems to improve nonlinear responses, and can be used, with further improvements, to explore macroscopic quantum mechanics.

  8. Giant electric field enhancement in split ring resonators featuring nanometer-sized gaps.

    PubMed

    Bagiante, S; Enderli, F; Fabiańska, J; Sigg, H; Feurer, T

    2015-01-01

    Today's pulsed THz sources enable us to excite, probe, and coherently control the vibrational or rotational dynamics of organic and inorganic materials on ultrafast time scales. Driven by standard laser sources THz electric field strengths of up to several MVm(-1) have been reported and in order to reach even higher electric field strengths the use of dedicated electric field enhancement structures has been proposed. Here, we demonstrate resonant electric field enhancement structures, which concentrate the incident electric field in sub-diffraction size volumes and show an electric field enhancement as high as ~14,000 at 50 GHz. These values have been confirmed through a combination of near-field imaging experiments and electromagnetic simulations. PMID:25623373

  9. Generating giant and tunable nonlinearity in a macroscopic mechanical resonator from a single chemical bond.

    PubMed

    Huang, Pu; Zhou, Jingwei; Zhang, Liang; Hou, Dong; Lin, Shaochun; Deng, Wen; Meng, Chao; Duan, Changkui; Ju, Chenyong; Zheng, Xiao; Xue, Fei; Du, Jiangfeng

    2016-01-01

    Nonlinearity in macroscopic mechanical systems may lead to abundant phenomena for fundamental studies and potential applications. However, it is difficult to generate nonlinearity due to the fact that macroscopic mechanical systems follow Hooke's law and respond linearly to external force, unless strong drive is used. Here we propose and experimentally realize high cubic nonlinear response in a macroscopic mechanical system by exploring the anharmonicity in chemical bonding interactions. We demonstrate the high tunability of nonlinear response by precisely controlling the chemical bonding interaction, and realize, at the single-bond limit, a cubic elastic constant of 1 × 10(20) N m(-3). This enables us to observe the resonator's vibrational bi-states transitions driven by the weak Brownian thermal noise at 6 K. This method can be flexibly applied to a variety of mechanical systems to improve nonlinear responses, and can be used, with further improvements, to explore macroscopic quantum mechanics. PMID:27225287

  10. A case of a giant pseudoangiomatous stromal hyperplasia of the breast: magnetic resonance imaging findings.

    PubMed

    Solomou, Ekaterini; Kraniotis, Pantelis; Patriarcheas, Georgios

    2012-04-12

    Pseudoangiomatous stromal hyperplasia (PASH) of the breast is a benign myofibroblastic process. We present the case of a 17-year-old girl who underwent diagnostic work-up due to an enlargement of her left breast. She was submitted to ultrasounds and magnetic resonance imaging (MRI) which depicted a 14 cm lesion in her left breast. The patient was later operated and histology revealed PASH. Although PASH may range from 0.6-12 cm, a few lesions over 12 cm have been described, the largest being 20 cm. Large series present mammographic and ultrasonographic features of PASH in the literature, but little has been reported on the MR characteristics of PASH up to today. Signal on the T1-weighted image (T1WI) and T2-weighted image (T2WI) may vary. Curves generated from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) studies are mainly type I or less frequently type II. There are no reports about diffusion-weighted imaging and corresponding apparent diffusion coefficient (ADC) values for PASH in the literature. ADC values in our case lie within the range of values reported for other benign breast lesions. The presence of slit-like spaces within the lesion on MR imaging along with DCE-MRI type I curve and ADC values consistent with a benign lesion may favour the diagnosis of PASH. Tissue biopsy is necessary, however for the final diagnosis. This case report will further contribute to the understanding of MR imaging features of PASH, especially in cases where mammography is not indicated. PMID:22826780

  11. Planets around Giant Stars: Results from the Lick Survey

    NASA Astrophysics Data System (ADS)

    Quirrenbach, Andreas; Reffert, Sabine; Trifonov, Trifon; Bergmann, Christoph; Schwab, Christian

    2015-12-01

    We present results from a radial-velocity survey of 373 giant stars at Lick Observatory, which started in 1999. We have detected planets around 15 of these stars; an additional 20 stars host planet candidates. Companions with up to 25 Jupiter masses are rather commonly found around stars with about 2 Solar masses. The frequency of detected planetary companions appears to increase with metallicity. No planets or planet candidates are found around stars with more than 2.7 Solar masses, although our sample contains 113 such stars. We conclude that the occurrence rate of giant planets as a function of Stellar mass peaks around 2 Solar masses. This has important consequences for our understanding of giant planet formation.The stars 91 Aqr and tau Gem have companions with orbits that are among those with the lowest eccentricities of all known exoplanets, perhaps due to tidal circularization during the RGB phase. If confirmed, this would be the first evidence of planetary orbits modified through stellar evolution.We have discovered several multiple systems in our sample. An extensive dynamical analysis of the eta Cet system indicates that it contains two massive planets in a 2:1 orbital resonance. The star nu Oph is orbited by two brown dwarf companions in a 6:1 resonance. It is likely that they arrived in this resonance through migration in a circumstellar disk, arguing strongly that objects with more than 20 Jupiter masses can be formed in disks around Herbig Ae stars.

  12. Emerging giant resonant exciton induced by Ta substitution in anatase TiO2: A tunable correlation effect

    NASA Astrophysics Data System (ADS)

    Yong, Z.; Trevisanutto, P. E.; Chiodo, L.; Santoso, I.; Barman, A. R.; Asmara, T. C.; Dhar, S.; Kotlov, A.; Terentjevs, A.; Della Sala, F.; Olevano, V.; Rübhausen, M.; Venkatesan, T.; Rusydi, A.

    2016-05-01

    Titanium dioxide (TiO2) has rich physical properties with potential implications for both fundamental physics and new applications. To date, the main focus of applied research is to tune its optical properties, which is usually done via doping and/or nanoengineering. However, understanding the role of d electrons in materials and possible functionalization of d -electron properties are still major challenges. Herewith, within a combination of an innovative experimental technique, high-energy optical conductivity, and state-of-the-art ab initio electronic structure calculations, we report an emerging, novel resonant exciton in the deep ultraviolet region of the optical response. The resonant exciton evolves upon low-concentration Ta substitution in anatase TiO2 films. It is surprisingly robust and related to strong electron-electron and electron-hole interactions. The d - and f -orbital localization, due to Ta substitution, plays an unexpected role, activating strong electronic correlations and dominating the optical response under photoexcitation. Our results shed light on a new optical phenomenon in anatase TiO2 films and on the possibility of tuning electronic properties by Ta substitution.

  13. Investigation of probabilistic orbital evolution of near-Earth asteroids moving in the vicinity of resonances with Mercury

    NASA Astrophysics Data System (ADS)

    Galushina, T. Yu.; Titarenko, E. Yu

    2014-12-01

    The purpose of this work is the investigation of probabilistic orbital evolution of near-Earth asteroids (NEA) moving in the vicinity of resonances with Mercury. In order to identify such objects the equations of all NEA motion have been integrated on the time interval (1000, 3000 years). The initial data has been taken from the E. Bowell catalog on February 2014. The motion equations have been integrated numerically by Everhart method. The resonance characteristics are critical argument that defines the connection longitude of the asteroid and the planet and its time derivative, called resonance "band". The study has identified 15 asteroids moving in the vicinity of different resonances with Mercury. Six of them (52381 1993 HA, 172034 2001 WR1, 2008 VB1, 2009 KT4, 2013 CQ35, 2013 TH) move in the vicinity of the resonance 1/6, five of them (142561 2002 TX68, 159608 2002 AC2, 241370 2008 LW8, 2006 UR216, 2009 XB2) move in the vicinity of the resonance 1/9 and one by one asteroid moves in the vicinity of resonances 1/3, 1/7, 1/8 and 2/7 (2006 SE6, 2002 CV46, 2013 CN35 and 2006 VY2 respectively). The orbits of all identified asteroids have been improved by least square method using the available optical observations and probabilistic orbital evolution has been investigated. Improvement have been carried out at the time of the best conditionality in accounting perturbations from the major planets, Pluto, Moon, Ceres, Pallas and Vesta, the relativistic effects from the Sun and the Solar oblateness. The estimation of the nonlinearity factor has showed that for all the considered NEA it does not exceed the critical value of 0.1, which makes it possible to use the linear method for constructing the initial probability domain. The domain has been built in the form of an ellipsoid in six-dimensional phase space of coordinates and velocity components on the base of the full covariance matrix, the center of ellipsoid is the nominal orbit obtained by improving. The 10 000

  14. Measurement of Resonance Parameters of Orbitally Excited Narrow B^0 Mesons

    SciTech Connect

    Aaltonen, : T.

    2008-09-01

    The authors report a measurement of resonance parameters of the orbitally excited (L = 1) narrow B{sup 0} mesons in decays to B{sup (*)+}{pi}{sup -} using 1.7 fb{sup -1} of data collected by the CDF II detector at the Fermilab Tevatron. The mass and width of the B*{sub 2}{sup 0} state are measured to be m(B*{sub 2}{sup 0}) = 5740.2{sub -1.8}{sup +1.7}(stat.){sub -0.8}{sup +0.9}(syst.) MeV/c{sup 2} and {Lambda}(B*{sub 2}{sup 0}) = 22.7{sub -3.2}{sup +3.8}(stat.){sub -10.2}{sup +3.2}(syst.) MeV/c{sub 2}. The mass difference between the B*{sub 2}{sup 0} and B{sub 1}{sup 0} states is measured to be 14.9{sub -2.5}{sup +2.2}(stat.){sub -1.4}{sup +1.2}(syst.) MeV/c{sup 2}, resulting in a B{sub 1}{sup 0} mass of 5725.3{sub -2.2}{sup +1.6}(stat.){sub -1.5}{sup +1.4}(syst.) MeV/c{sup 2}. This is currently the most precise measurement of the masses of these states and the first measurement of the B*{sub 2}{sup 0} width.

  15. Measurement of resonance parameters of orbitally excited narrow B0 mesons.

    PubMed

    Aaltonen, T; Adelman, J; Akimoto, T; Albrow, M G; González, B Alvarez; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Apollinari, G; Apresyan, A; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Aurisano, A; Azfar, F; Azzurri, P; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Bartsch, V; Bauer, G; Beauchemin, P-H; Bedeschi, F; Beecher, D; Behari, S; Bellettini, G; Bellinger, J; Benjamin, D; Beretvas, A; Beringer, J; Bhatti, A; Binkley, M; Bisello, D; Bizjak, I; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bolla, G; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Bridgeman, A; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Burke, S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Byrum, K L; Cabrera, S; Calancha, C; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carls, B; Carlsmith, D; Carosi, R; Carrillo, S; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavaliere, V; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, K; Chokheli, D; Chou, J P; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Chwalek, T; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Compostella, G; Convery, M E; Conway, J; Cordelli, M; Cortiana, G; Cox, C A; Cox, D J; Crescioli, F; Almenar, C Cuenca; Cuevas, J; Culbertson, R; Cully, J C; Dagenhart, D; Datta, M; Davies, T; de Barbaro, P; De Cecco, S; Deisher, A; De Lorenzo, G; Dell'orso, M; Deluca, C; Demortier, L; Deng, J; Deninno, M; Derwent, P F; di Giovanni, G P; Dionisi, C; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Donati, S; Dong, P; Donini, J; Dorigo, T; Dube, S; Efron, J; Elagin, A; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Ferrazza, C; Field, R; Flanagan, G; Forrest, R; Frank, M J; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garberson, F; Garcia, J E; Garfinkel, A F; Genser, K; Gerberich, H; Gerdes, D; Gessler, A; Giagu, S; Giakoumopoulou, V; Giannetti, P; Gibson, K; Gimmell, J L; Ginsburg, C M; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Grinstein, S; Grosso-Pilcher, C; Grundler, U; da Costa, J Guimaraes; Gunay-Unalan, Z; Haber, C; Hahn, K; Hahn, S R; Halkiadakis, E; Han, B-Y; Han, J Y; Happacher, F; Hara, K; Hare, D; Hare, M; Harper, S; Harr, R F; Harris, R M; Hartz, M; Hatakeyama, K; Hays, C; Heck, M; Heijboer, A; Heinrich, J; Henderson, C; Herndon, M; Heuser, J; Hewamanage, S; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Hou, S; Houlden, M; Hsu, S-C; Huffman, B T; Hughes, R E; Husemann, U; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ivanov, A; James, E; Jayatilaka, B; Jeon, E J; Jha, M K; Jindariani, S; Johnson, W; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; Kar, D; Karchin, P E; Kato, Y; Kephart, R; Keung, J; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, H W; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirsch, L; Klimenko, S; Knuteson, B; Ko, B R; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kreps, M; Kroll, J; Krop, D; Krumnack, N; Kruse, M; Krutelyov, V; Kubo, T; Kuhr, T; Kulkarni, N P; Kurata, M; Kusakabe, Y; Kwang, S; Laasanen, A T; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; Lecompte, T; Lee, E; Lee, H S; Lee, S W; Leone, S; Lewis, J D; Lin, C-S; Linacre, J; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, C; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; Lovas, L; Lucchesi, D; Luci, C; Lueck, J; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; Macqueen, D; Madrak, R; Maeshima, K; Makhoul, K; Maki, T; Maksimovic, P; Malde, S; Malik, S; Manca, G; Manousakis-Katsikakis, A; Margaroli, F; Marino, C; Marino, C P; Martin, A; Martin, V; Martínez, M; Martínez-Ballarín, R; Maruyama, T; Mastrandrea, P; Masubuchi, T; Mathis, M; Mattson, M E; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzione, A; Merkel, P; Mesropian, C; Miao, T; Miladinovic, N; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyake, H; Moggi, N; Moon, C S; Moore, R; Morello, M J; Morlok, J; Fernandez, P Movilla; Mülmenstädt, J; Mukherjee, A; Muller, Th; Mumford, R; Murat, P; Mussini, M; Nachtman, J; Nagai, Y; Nagano, A; Naganoma, J; Nakamura, K; Nakano, I; Napier, A; Necula, V; Nett, J; Neu, C; Neubauer, M S; Neubauer, S; Nielsen, J; Nodulman, L; Norman, M; Norniella, O; Nurse, E; Oakes, L; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Orava, R; Griso, S Pagan; Palencia, E; Papadimitriou, V; Papaikonomou, A; Paramonov, A A; Parks, B; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Peiffer, T; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Pianori, E; Pinera, L; Pitts, K; Plager, C; Pondrom, L; Poukhov, O; Pounder, N; Prakoshyn, F; Pronko, A; Proudfoot, J; Ptohos, F; Pueschel, E; Punzi, G; Pursley, J; Rademacker, J; Rahaman, A; Ramakrishnan, V; Ranjan, N; Redondo, I; Rekovic, V; Renton, P; Renz, M; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rodriguez, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Roy, P; Ruiz, A; Russ, J; Rusu, V; Safonov, A; Sakumoto, W K; Saltó, O; Santi, L; Sarkar, S; Sartori, L; Sato, K; Savoy-Navarro, A; Schlabach, P; Schmidt, A; Schmidt, E E; Schmidt, M A; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sexton-Kennedy, L; Sforza, F; Sfyrla, A; Shalhout, S Z; Shears, T; Shepard, P F; Shimojima, M; Shiraishi, S; Shochet, M; Shon, Y; Shreyber, I; Sidoti, A; Sinervo, P; Sisakyan, A; Slaughter, A J; Slaunwhite, J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Soha, A; Somalwar, S; Sorin, V; Spalding, J; Spreitzer, T; Squillacioti, P; Stanitzki, M; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Strycker, G L; Stuart, D; Suh, J S; Sukhanov, A; Suslov, I; Suzuki, T; Taffard, A; Takashima, R; Takeuchi, Y; Tanaka, R; Tecchio, M; Teng, P K; Terashi, K; Thom, J; Thompson, A S; Thompson, G A; Thomson, E; Tipton, P; Ttito-Guzmán, P; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Totaro, P; Tourneur, S; Trovato, M; Tsai, S-Y; Tu, Y; Turini, N; Ukegawa, F; Vallecorsa, S; van Remortel, N; Varganov, A; Vataga, E; Vázquez, F; Velev, G; Vellidis, C; Veszpremi, V; Vidal, M; Vidal, R; Vila, I; Vilar, R; Vine, T; Vogel, M; Volobouev, I; Volpi, G; Wagner, P; Wagner, R G; Wagner, R L; Wagner, W; Wagner-Kuhr, J; Wakisaka, T; Wallny, R; Wang, S M; Warburton, A; Waters, D; Weinberger, M; Weinelt, J; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Wilbur, S; Williams, G; Williams, H H; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, C; Wright, T; Wu, X; Würthwein, F; Wynne, S M; Xie, S; Yagil, A; Yamamoto, K; Yamaoka, J; Yang, U K; Yang, Y C; Yao, W M; Yeh, G P; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanello, L; Zanetti, A; Zhang, X; Zheng, Y; Zucchelli, S

    2009-03-13

    We report a measurement of resonance parameters of the orbitally excited (L=1) narrow B0 mesons in decays to B;{(*)+}pi;{-} using 1.7 fb;{-1} of data collected by the CDF II detector at the Fermilab Tevatron. The mass and width of the B_{2};{*0} state are measured to be m(B_{2};{*0})=5740.2_{-1.8};{+1.7}(stat)-0.8+0.9(syst) MeV/c;{2} and Gamma(B_{2};{*0})=22.7_{-3.2};{+3.8}(stat)-10.2+3.2(syst) MeV/c;{2}. The mass difference between the B_{2};{*0} and B10 states is measured to be 14.9_{-2.5};{+2.2}(stat)-1.4+1.2(syst) MeV/c;{2}, resulting in a B10 mass of 5725.3_{-2.2};{+1.6}(stat)-1.5+1.4(syst) MeV/c;{2}. This is currently the most precise measurement of the masses of these states and the first measurement of the B_{2};{*0} width. PMID:19392106

  16. Evaluation of multiatlas label fusion for in vivo magnetic resonance imaging orbital segmentation

    PubMed Central

    Panda, Swetasudha; Asman, Andrew J.; Khare, Shweta P.; Thompson, Lindsey; Mawn, Louise A.; Smith, Seth A.; Landman, Bennett A.

    2014-01-01

    Abstract. Multiatlas methods have been successful for brain segmentation, but their application to smaller anatomies remains relatively unexplored. We evaluate seven statistical and voting-based label fusion algorithms (and six additional variants) to segment the optic nerves, eye globes, and chiasm. For nonlocal simultaneous truth and performance level estimation (STAPLE), we evaluate different intensity similarity measures (including mean square difference, locally normalized cross-correlation, and a hybrid approach). Each algorithm is evaluated in terms of the Dice overlap and symmetric surface distance metrics. Finally, we evaluate refinement of label fusion results using a learning-based correction method for consistent bias correction and Markov random field regularization. The multiatlas labeling pipelines were evaluated on a cohort of 35 subjects including both healthy controls and patients. Across all three structures, nonlocal spatial STAPLE (NLSS) with a mixed weighting type provided the most consistent results; for the optic nerve NLSS resulted in a median Dice similarity coefficient of 0.81, mean surface distance of 0.41 mm, and Hausdorff distance 2.18 mm for the optic nerves. Joint label fusion resulted in slightly superior median performance for the optic nerves (0.82, 0.39 mm, and 2.15 mm), but slightly worse on the globes. The fully automated multiatlas labeling approach provides robust segmentations of orbital structures on magnetic resonance imaging even in patients for whom significant atrophy (optic nerve head drusen) or inflammation (multiple sclerosis) is present. PMID:25558466

  17. Condensate fraction of a resonant Fermi gas with spin-orbit coupling in three and two dimensions

    SciTech Connect

    Dell'Anna, L.; Mazzarella, G.; Salasnich, L.

    2011-09-15

    We study the effects of laser-induced Rashba-like spin-orbit coupling along the Bardeen-Cooper-Schrieffer-Bose-Einstein condensate (BCS-BEC) crossover of a Feshbach resonance for a two-spin-component Fermi gas. We calculate the condensate fraction in three and two dimensions and find that this quantity characterizes the crossover better than other quantities, like the chemical potential or the pairing gap. By considering both the singlet and the triplet pairings, we calculate the condensate fraction and show that a large-enough spin-orbit interaction enhances the singlet condensate fraction in the BCS side while suppressing it on the BEC side.

  18. Adiabatic invariants and phase equilibria for first-order orbital resonances. [solar mass change effect on asteroid orbits

    NASA Technical Reports Server (NTRS)

    Heppenheimer, T. A.

    1975-01-01

    In the planar circular restricted three-body problem, the evolution of near-commensurable orbits is studied under change in the mass ratio, mu. The evolution involves preservation of two adiabatic invariants. Transition from circulation to libration may occur; such transitions are of two types. Type I transition occurs when the evolutionary track in phase space passes through near-zero eccentricity; as in the ordinary case (no transition), pre- and post-evolutionary states are linked by solution of a two-point boundary-value problem. Type II transition occurs when the evolutionary track encounters an unstable phase equilibrium or periodic orbit. There is then a discontinuous change in one adiabatic invariant, and pre- and post-evolutionary states are linked by solution of a three-point boundary-value problem. No evolutionary track can encounter a stable phase equilibrium, but the class of all stable phase equilibria is mapped into itself under mu change.

  19. Dynamical evolution and spin-orbit resonances of potentially habitable exoplanets. The case of GJ 667C

    SciTech Connect

    Makarov, Valeri V.; Berghea, Ciprian

    2014-01-10

    We investigate the spin-orbital evolution of the potentially habitable super-Earth GJ 667Cc in the multiple system of at least two exoplanets orbiting a nearby M dwarf. The published radial velocities for this star are re-analyzed and evidence is found for additional periodic signals, which could be taken for two additional planets on eccentric orbits making the system dynamically inviable. Limiting the scope to the two originally detected planets, we assess the dynamical stability of the system and find no evidence for bounded chaos in the orbital motion. The orbital eccentricity of the planets b and c is found to change cyclically in the range 0.06-0.28 and 0.05-0.25, respectively, with a period of approximately 0.46 yr. Taking the eccentricity variation into account, numerical integrations are performed of the spin-orbit interactions of the planet GJ 667Cc with its host star, assuming a terrestrial composition of its mantle. Depending on the interior temperature of the planet, it is likely to be entrapped in the 3:2 (probability 0.51) or even higher spin-orbit resonance. It is less likely to reach the 1:1 resonance (probability 0.24). The estimated characteristic spin-down times are quite short for the two planets, i.e., within 1 Myr for planet c and even shorter for planet b. The rate of tidal dissipation of energy in the planets of GJ 667 is estimated at 10{sup 23.7} and 10{sup 26.7} J yr{sup –1} for c and b, respectively. This raises a question of how such relatively massive, close super-Earths could survive overheating and destruction.

  20. Giant distal humeral geode.

    PubMed

    Maher, M M; Kennedy, J; Hynes, D; Murray, J G; O'Connell, D

    2000-03-01

    We describe the imaging features of a giant geode of the distal humerus in a patient with rheumatoid arthritis, which presented initially as a pathological fracture. The value of magnetic resonance imaging in establishing this diagnosis is emphasized. PMID:10794554

  1. Resonance capture at arbitrary inclination

    NASA Astrophysics Data System (ADS)

    Namouni, F.; Morais, M. H. M.

    2015-01-01

    Resonance capture is studied numerically in the three-body problem for arbitrary inclinations. Massless particles are set to drift from outside the 1:5 resonance with a Jupiter-mass planet thereby encountering the web of the planet's diverse mean motion resonances. Randomly constructed samples explore parameter space for inclinations from 0 to 180° with 5° increments totalling nearly 6 × 105 numerical simulations. 30 resonances internal and external to the planet's location are monitored. We find that retrograde resonances are unexpectedly more efficient at capture than prograde resonances and that resonance order is not necessarily a good indicator of capture efficiency at arbitrary inclination. Capture probability drops significantly at moderate sample eccentricity for initial inclinations in the range [10°,110°]. Orbit inversion is possible for initially circular orbits with inclinations in the range [60°,130°]. Capture in the 1:1 co-orbital resonance occurs with great likelihood at large retrograde inclinations. The planet's orbital eccentricity, if larger than 0.1, reduces the capture probabilities through the action of the eccentric Kozai-Lidov mechanism. A capture asymmetry appears between inner and outer resonances as prograde orbits are preferentially trapped in inner resonances. The relative capture efficiency of retrograde resonance suggests that the dynamical lifetimes of Damocloids and Centaurs on retrograde orbits must be significantly larger than those on prograde orbits implying that the recently identified asteroids in retrograde resonance, 2006 BZ8, 2008 SO218, 2009 QY6 and 1999 LE31 may be among the oldest small bodies that wander between the outer giant planets.

  2. Sustained Magnetic Connections from L1: IMAP Science with Planetary Transfers and Hohmann-Parker Resonance Orbits

    NASA Astrophysics Data System (ADS)

    Posner, A.; Droege, W.; Hayes, J. J.; Heber, B.; Odstrcil, D.; Wicks, R.

    2014-12-01

    Simultaneous heliospheric observations of particles, fields, and plasma on closely connected interplanetary magnetic field lines at large (~AU) distances from one another have large potential for addressing many critical science problems in Heliophysics. These include investigations into particle acceleration and transport, the magnetic structure of the inner heliosphere, and solar wind turbulence. We have determined that spacecraft launched from Earth towards Mars and Venus following a Hohmann minimum energy transfer trajectory provide such opportunities as they have a strong tendency to remain well-connected magnetically to Earth (L1) via the Parker magnetic field in the heliosphere. Along with the finding that magnetic connections also established on the return journeys we refer to this circumstance as the Hohmann-Parker effect. Thus, IMAP placement at L1 would have obvious advantages for human exploration missions to and from Mars. In particular the early mission phases of current and future science missions such as MSL, MAVEN, Solar Orbiter, Mars 2020 and beyond provide opportunities for Heliophysics science gain. We already have predicted and confirmed consequences of the effect as correlated high-energy particle parameters at L1 and MSL. We will reiterate predictions and make WSA-ENLIL simulations for the MAVEN s/c orbital path during its transfer from Earth to Mars in 2013/2014. Moreover, we predict the existence of Hohmann-Parker resonance orbits that reestablish HP-effect conditions and evaluate and compare the science value of various resonance orbits. Smallsat missions on such resonance orbits in combination with IMAP would in the future provide us with enormous recurring science potential to solve key Heliophysics science questions.

  3. Photoionization of Xe inside C{sub 60}: Atom-fullerene hybridization, giant cross-section enhancement, and correlation confinement resonances

    SciTech Connect

    Madjet, Mohamed E.; Renger, Thomas; Hopper, Dale E.; McCune, Matthew A.; Chakraborty, Himadri S.; Rost, Jan-M.; Manson, Steven T.

    2010-01-15

    A theoretical study of the subshell photoionization of the Xe atom endohedrally confined in C{sub 60} is presented. Powerful hybridization of the Xe 5s state with the bottom edge of C{sub 60} pi band is found that induces strong structures in the 5s ionization, causing the cross section to differ significantly from earlier results that omit this hybridization. The hybridization also affects the angular distribution asymmetry parameter of Xe 5p ionization near the Cooper minimum. The 5p cross section, on the other hand, is greatly enhanced by borrowing considerable oscillator strength from the C{sub 60} giant plasmon resonance via the atom-fullerene dynamical interchannel coupling. Beyond the C{sub 60} plasmon energy range the atomic subshell cross sections display confinement-induced oscillations in which, over the large 4d shape resonance region, the dominant 4d oscillations induce their 'clones' in all degenerate weaker channels known as correlation confinement resonances.

  4. 1 to 2.4 microns spectrum and orbital properties of the Giant Planet Beta Pictoris b obtained with the Gemini Planet Imager

    NASA Astrophysics Data System (ADS)

    Pueyo, Laurent; Chilcote, Jeffrey; Millar-Blanchaer, Max; Barman, Travis; Fitzgerald, Michael P.; Graham, James R.; Larkin, James; Kalas, Paul G.; dawson, Rebekah; Wang, Jason; Perrin, Marshall; Moon, Dae-Sik; Macintosh, Bruce

    2015-12-01

    We present a low-resolution multi-band spectrum of the planetary companion to the nearby young star beta Pictoris using the Gemini Planet Imager (GPI). GPI is designed to image and provide low-resolution spectra of Jupiter sized, self-luminous planetary companions around young nearby stars. While H-bandis the primary workhorse for the GPI Exoplanet Survey, the instrument is capable of observing in the near infrared covering Y, J, H, and K bands. These observations of Beta Pic Pictoris b were taken covering multiple bands as part of GPI’s verification and commissioning phase in 2013 and 2014. Using atmospheric models along with the H-band data we recently reported an effective temperature of 1600-1700 K and a surface gravity of log (g) = 3.5-4.5 (cgs units). A similar exercise was also carried out by an independent team using the J band data, and did yield similar conclusions. These values agree well with ”hot-start” predictions from planetary evolution models for a gas giant with mass between 10 and 12 M Jup and age between 10 and 20 Myr. Here we revisit these conclusions in light of a joint analysis of these two datasets along with the longer wavelength GPI spectrum in K band, and present refined constraints on the atmospheric properties of this giant planet. In addition, we present an updated orbit for Beta Pictoris b based on astrometric measurements taken using commissioning and subsequent monitoring observations, spanning 14 months. The planet has a semi-major axis of 9.2 (+1.5 -0.4) AU, with an eccentricity e≤ 0.26. The position angle of the ascending node is Ω=31.75 deg±0.15, offset from both the outer main disk and the inner disk seen in the GPI image. We finally discuss these properties in the context of planet-disk dynamical interactions.

  5. X-Ray Detected Magnetic Resonance: A Unique Probe of the Precession Dynamics of Orbital Magnetization Components

    PubMed Central

    Goulon, Jośe; Rogalev, Andrei; Goujon, Gérard; Wilhelm, Fabrice; Ben Youssef, Jamal; Gros, Claude; Barbe, Jean-Michel; Guilard, Roger

    2011-01-01

    X-ray Detected Magnetic Resonance (XDMR) is a novel spectroscopy in which X-ray Magnetic Circular Dichroism (XMCD) is used to probe the resonant precession of local magnetization components in a strong microwave pump field. We review the conceptual bases of XDMR and recast them in the general framework of the linear and nonlinear theories of ferromagnetic resonance (FMR). Emphasis is laid on the information content of XDMR spectra which offer a unique opportunity to disentangle the precession dynamics of spin and orbital magnetization components at given absorbing sites. For the sake of illustration, we focus on selected examples in which marked differences were found between FMR and XDMR spectra simultaneously recorded on ferrimagnetically ordered iron garnets. With pumping capabilities extended up to sub-THz frequencies, high-field XDMR should allow us to probe the precession of orbital magnetization components in paramagnetic organometallic complexes with large zero-field splitting. Even more challenging, we suggest that XDMR spectra might be recorded on selected antiferromagnetic crystals for which orbital magnetism is most often ignored in the absence of any supporting experimental evidence. PMID:22272105

  6. One-dimensional quantum antiferromagnetism in the p -orbital CsO2 compound revealed by electron paramagnetic resonance

    NASA Astrophysics Data System (ADS)

    Knaflič, Tilen; Klanjšek, Martin; Sans, Annette; Adler, Peter; Jansen, Martin; Felser, Claudia; Arčon, Denis

    2015-05-01

    Recently, it was proposed that the orbital ordering of πx,y * molecular orbitals in the superoxide CsO2 compound leads to the formation of spin-1/2 chains below the structural phase transition occurring at Ts 1=61 K on cooling. Here we report a detailed X -band electron paramagnetic resonance (EPR) study of this phase in CsO2 powder. The EPR signal appears as a broad line below Ts 1, which is replaced by the antiferromagnetic resonance below the Néel temperature TN=8.3 K . The temperature dependence of the EPR linewidth between Ts 1 and TN agrees with the predictions for the one-dimensional Heisenberg antiferromagnetic chain of S =1 /2 spins in the presence of symmetric anisotropic exchange interaction. Complementary analysis of the EPR line shape, linewidth, and the signal intensity within the Tomonaga-Luttinger liquid (TLL) framework allows for a determination of the TLL exponent K =0.48 . Present EPR data thus fully comply with the quantum antiferromagnetic state of spin-1/2 chains in the orbitally ordered phase of CsO2, which is therefore a unique p -orbital system where such a state could be studied.

  7. Prenatal assessment of a fast-growing giant epignathus.

    PubMed

    Faghfouri, Farahnaz; Bucourt, Martine; Garel, Catherine; Benchimol, Michel; Amarenco, Brigitte; Soupre, Véronique; Benbara, Amélie; Carbillon, Lionel

    2014-02-01

    Epignathus is a very rare fetal tumor. We report a case of fast-growing giant epignathus with severe distortion of the right part of the face and orbit. A thorough prenatal work-up was performed by the association of Magnetic Resonance Imaging and Ultrasonography. A multidisciplinary approach was crucial to assess the operability and provide careful counseling to help parents understand and reach decision. PMID:24164281

  8. Observation of orbiting resonances in He({sup 3}S{sub 1}) + NH{sub 3} Penning ionization

    SciTech Connect

    Jankunas, Justin; Osterwalder, Andreas; Jachymski, Krzysztof; Hapka, Michał

    2015-04-28

    Resonances are among the clearest quantum mechanical signatures of scattering processes. Previously, shape resonances and Feshbach resonances have been observed in inelastic and reactive collisions involving atoms or diatomic molecules. Structure in the integral cross section has been observed in a handful of elastic collisions involving polyatomic molecules. The present paper presents the observation of shape resonances in the reactive scattering of a polyatomic molecule, NH{sub 3}. A merged-beam study of the gas phase He({sup 3}S{sub 1}) + NH{sub 3} Penning ionization reaction dynamics is described in the collision energy range 3.3 μeV < E{sub coll} < 10 meV. In this energy range, the reaction rate is governed by long-range attraction. Peaks in the integral cross section are observed at collision energies of 1.8 meV and 7.3 meV and are assigned to ℓ = 15,16 and ℓ = 20,21 partial wave resonances, respectively. The experimental results are well reproduced by theoretical calculations with the short-range reaction probability P{sub sr} = 0.035. No clear signature of the orbiting resonances is visible in the branching ratio between NH{sub 3}{sup +} and NH{sub 2}{sup +} formation.

  9. Structure of the Asteroid Belt from the Gas Giants' Growth and Chaotic Dynamics

    NASA Astrophysics Data System (ADS)

    Izidoro, André; Raymond, Sean N.; Pierens, Arnaud; Morbidelli, Alessandro; Winter, Othon; Nesvorny, David

    2016-05-01

    The structure of the asteroid belt holds a record of the Solar System's dynamical history. The current belt only contains 10-3 Earth masses yet the asteroids' orbits are dynamically excited, with a large spread in eccentricity and inclination. The belt is also chemically segregated: the inner belt is dominated by dry S-types and the outer belt by hydrated C-types. Here we propose a new model in which the asteroid belt was always low-mass and was partially populated and sculpted by the giant planets on chaotic, resonant orbits. We first show that the compositional dichotomy of the asteroid belt is a simple consequence of Jupiter's growth in the gaseous protoplanetary disk. As Jupiter's core rapidly grew by accreting gas, orbits of nearby planetesimals were perturbed onto Jupiter-crossing trajectories. A significant fraction (~10%) of objects in the neighborhood exterior of Jupiter's orbit were implanted by gas drag into the outer parts of the asteroid belt as C-types. While the gas giants were likely in mean motion resonance at the end of the gaseous disk phase, we show that small perturbations may have driven them into a chaotic but stable state. After the dissipation of the gaseous disk, stochastic variations in the gas giants orbits caused resonances to chaotically jump across the main belt and excite the asteroids' orbits. Our results suggest that the early Solar System was chaotic and introduce a simple framework to understand the origins of the asteroid belt.

  10. Atmosphere expansion and mass loss of close-orbit giant exoplanets heated by stellar XUV. I. Modeling of hydrodynamic escape of upper atmospheric material

    SciTech Connect

    Shaikhislamov, I. F.; Khodachenko, M. L.; Sasunov, Yu. L.; Lammer, H.; Kislyakova, K. G.; Erkaev, N. V.

    2014-11-10

    In the present series of papers we propose a consistent description of the mass loss process. To study in a comprehensive way the effects of the intrinsic magnetic field of a close-orbit giant exoplanet (a so-called hot Jupiter) on atmospheric material escape and the formation of a planetary inner magnetosphere, we start with a hydrodynamic model of an upper atmosphere expansion in this paper. While considering a simple hydrogen atmosphere model, we focus on the self-consistent inclusion of the effects of radiative heating and ionization of the atmospheric gas with its consequent expansion in the outer space. Primary attention is paid to an investigation of the role of the specific conditions at the inner and outer boundaries of the simulation domain, under which different regimes of material escape (free and restricted flow) are formed. A comparative study is performed of different processes, such as X-ray and ultraviolet (XUV) heating, material ionization and recombination, H{sub 3}{sup +} cooling, adiabatic and Lyα cooling, and Lyα reabsorption. We confirm the basic consistency of the outcomes of our modeling with the results of other hydrodynamic models of expanding planetary atmospheres. In particular, we determine that, under the typical conditions of an orbital distance of 0.05 AU around a Sun-type star, a hot Jupiter plasma envelope may reach maximum temperatures up to ∼9000 K with a hydrodynamic escape speed of ∼9 km s{sup –1}, resulting in mass loss rates of ∼(4-7) · 10{sup 10} g s{sup –1}. In the range of the considered stellar-planetary parameters and XUV fluxes, that is close to the mass loss in the energy-limited case. The inclusion of planetary intrinsic magnetic fields in the model is a subject of the follow-up paper (Paper II).

  11. Orbital and physical parameters of eclipsing binaries from the ASAS catalogue - VIII. The totally eclipsing double-giant system HD 187669

    NASA Astrophysics Data System (ADS)

    Hełminiak, K. G.; Graczyk, D.; Konacki, M.; Pilecki, B.; Ratajczak, M.; Pietrzyński, G.; Sybilski, P.; Villanova, S.; Gieren, W.; Pojmański, G.; Konorski, P.; Suchomska, K.; Reichart, D. E.; Ivarsen, K. M.; Haislip, J. B.; LaCluyze, A. P.

    2015-04-01

    We present the first full orbital and physical analysis of HD 187669, recognized by the All-Sky Automated Survey (ASAS) as the eclipsing binary ASAS J195222-3233.7. We combined multi-band photometry from the ASAS and SuperWASP public archives and 0.41-m PROMPT robotic telescopes with our high-precision radial velocities from the HARPS spectrograph. Two different approaches were used for the analysis: (1) fitting to all data simultaneously with the WD code and (2) analysing each light curve (with JKTEBOP) and radial velocities separately and combining the partial results at the end. This system also shows a total primary (deeper) eclipse, lasting for about 6 d. A spectrum obtained during this eclipse was used to perform atmospheric analysis with the MOOG and SME codes to constrain the physical parameters of the secondary. We found that ASAS J195222-3233.7 is a double-lined spectroscopic binary composed of two evolved, late-type giants, with masses of M1 = 1.504 ± 0.004 and M2 = 1.505 ± 0.004 M⊙, and radii of R1 = 11.33 ± 0.28 and R2 = 22.62 ± 0.50 R⊙. It is slightly less metal abundant than the Sun, and has a P = 88.39 d orbit. Its properties are well reproduced by a 2.38-Gyr isochrone, and thanks to the metallicity estimation from the totality spectrum and high precision of the masses, it was possible to constrain the age down to 0.1 Gyr. It is the first so evolved Galactic eclipsing binary measured with such good accuracy, and as such it is a unique benchmark for studying the late stages of stellar evolution.

  12. First Detection of a Dust Disk around Iota Horologii, a Southern Star Orbitted by an Extrasolar Giant Planet

    NASA Astrophysics Data System (ADS)

    Pantin, E.; Els, S.; Marchis, F.; Endl, M.; Kürster, M.; Sterzik, M.

    2000-12-01

    The link between the presence of debris dust disks (Vega phenomenon) and planetary formation is still unclear; are they: excluding children, siamese twins, or just casual neighbours? Recenly, Trilling et al. (1999), thanks to coronograph observations in the Northern hemisphere, showed that 3 out of 6 stars with known planetary companions harbour a tenuous dust disk, probably some precursors to the analogues of our Solar System Kuiper belt and zodiacal disk. We have started to conduct a similar program in the southern hemisphere at the ESO 3.6m telescope using the adaptive optics system ADONIS. H band images taken in coronographic mode during good observing conditions reveal the presence of a tenuous dust disk around the star Iota Horologii. This star is know to have a planetary companion of 2.26 M.sin i Jupiter masses on a 1 AU orbit, revealed by radial velocities analysis. The ADONIS images show that the disk has an inclination with a tilt angle of 40 degrees with respect to the edge-on configuration. This information allows to remove the degeneracy on the estimation of the mass of the planet due to the unknown inclination of the orbit. Taking this value into account, we find that the planet mass is 3.41 Jupiter masses. In our ADONIS observations, the disk extends 3.7 arcsec from the star, i.e. about 65 AU taking into account the distance of 17 parcsecs of this system. Modelling of light scattering by dust particles are shown and compared to the observations in order to deduce the disk density profile. This density profile is compared to previous results on disks around Beta Pic and HD 100546.

  13. [Orbital non-Hodgkin's lymphoma: description of a case diagnosed with magnetic resonance imaging].

    PubMed

    Macarini, Luca; Cotroneo, Antonio Raffaele; Zeppa, Pio; Briganti, Francesco; Genovese, Eugenio Annibale

    2012-11-01

    Orbital non-Hodgkin's lymphoma is a rare tumor. Correct diagnosis and accurate staging are of paramount importance for timely treatment and better outcome. We report the case of a female patient with bilateral orbital lymphoma, and describe the clinical-pathological aspects of the disease and its neuroradiological features. PMID:23096746

  14. Giant electric field control of magnetism and narrow ferromagnetic resonance linewidth in FeCoSiB/Si/SiO2/PMN-PT multiferroic heterostructures

    NASA Astrophysics Data System (ADS)

    Gao, Y.; Wang, X.; Xie, L.; Hu, Z.; Lin, H.; Zhou, Z.; Nan, T.; Yang, X.; Howe, B. M.; Jones, J. G.; Brown, G. J.; Sun, N. X.

    2016-06-01

    It has been challenging to achieve combined strong magnetoelectric coupling and narrow ferromagnetic resonance (FMR) linewidth in multiferroic heterostructures. Electric field induced large effective field of 175 Oe and narrow FMR linewidth of 40 Oe were observed in FeCoSiB/Si/SiO2/PMN-PT heterostructures with substrate clamping effect minimized through removing the Si substrate. As a comparison, FeCoSiB/PMN-PT heterostructures with FeCoSiB film directly deposited on PMN-PT showed a comparable voltage induced effective magnetic field but a significantly larger FMR linewidth of 283 Oe. These multiferroic heterostructures exhibiting combined giant magnetoelectric coupling and narrow ferromagnetic resonance linewidth offer great opportunities for integrated voltage tunable RF magnetic devices.

  15. Application of magnetic resonance imaging and three-dimensional treatment planning in the treatment of orbital lymphoma.

    PubMed

    Rudoltz, M S; Ayyangar, K; Mohiuddin, M

    1993-01-01

    Radiotherapy for lymphoma of the orbit must be individualized for each patient and clinical setting. Most techniques focus on optimizing the dose to the tumor while sparing the lens. This study describes a technique utilizing magnetic resonance imaging (MRI) and three dimensional (3D) planning in the treatment of orbital lymphoma. A patient presented with an intermediate grade lymphoma of the right orbit. The prescribed tumor dose was 4050 cGy in 18 fractions. Three D planning was carried out and tumor volumes, retina, and lens were subsequently outlined. Dose calculations including dose volume histograms of the target, retina, and lens were then performed. Part of the retina was outside of the treatment volume while 50% of the retina received 90% or more of the prescribed dose. The patient was clinically NED when last seen 2 years following therapy with no treatment-related morbidity. Patients with lymphomas of the orbit can be optimally treated using MRI based 3D treatment planning. PMID:8280364

  16. Orbital Optimization in the Resonating Hartree-Fock Approximation and Its Application to the One Dimensional Hubbard Model

    NASA Astrophysics Data System (ADS)

    Ikawa, Atsushi; Yamamoto, Shoji; Fukutome, Hideo

    1993-05-01

    A tractable direct optimization algorithm is developed to optimize orbitals in the Slater determinants (S-dets) in a resonating Hartree-Fock (Res HF) wave function. We reduce the variation space using the orbitals to put the first order energy variation in the steepest descent direction. The orbitals in the next iteration are determined so as to minimize the energy functional including up to the second order variation. This algorithm is applied to the one dimensional Hubbard model of half-filling. The optimized S-dets much deviate from the trial S-dets prepared from the HF calculations. The Res HF ground state generated with a few S-dets explains from 99.9 to 95.0% of the ground state correlation energy in all the correlation regimes. We have spin correlation functions with the correct short and long range behaviors and the lowest triplet and singlet spin excitations with correct dispersions, suggesting that the optimization of orbitals incorporates long range spin fluctuations and their mode-mode couplings.

  17. Nuclear magnetic resonance Knight shifts in the presence of strong spin–orbit and crystal-field potentials

    NASA Astrophysics Data System (ADS)

    Nisson, D. M.; Curro, N. J.

    2016-07-01

    In recent years there has been increasing interest in materials with strong spin–orbit coupling (SOC). Nuclear magnetic resonance is a valuable microscopic probe of such systems because of the hyperfine interactions between the nuclear spins and the electron degrees of freedom. In materials with weak SOC the NMR Knight shift contains two contributions: one from the electron orbital susceptibility and the other from the electron spin susceptibility. These contributions can be separated by plotting the Knight shift versus the bulk susceptibility and extracting the slope and intercept. Here we examine the case where the SOC is non-negligible, in which case the slope and intercept are no longer simply related to these two contributions. These results have important implications for NMR studies of heavy fermions, as well as 4d and 5d systems.

  18. Imaging of the pediatric orbit and visual pathways: computed tomography and magnetic resonance imaging.

    PubMed

    Davis, P C; Hopkins, K L

    1999-02-01

    Techniques for pediatric MR imaging and computed tomography and anatomy of the orbit and intracranial visual pathways are presented and reviewed in this article. Imaging findings are presented for the following categories of abnormality: a) orbital anomalies related to congenital disorders of the brain, b) disorders of the orbit (ocular, nonocular, or multicompartmental), c) disorders of the intracranial visual pathways (suprasellar cistern, optic radiations, or occipital cortex), and d) disorders of gaze (extraocular muscles, cranial nerves, and brainstem). Careful assessment of the clinical findings, anatomic location of the visual impairment, and familiarity with disorders that often affect pediatric patients are helpful in guiding neuroimaging evaluation of the child with ocular, orbital, or central patterns of visual disturbance. PMID:9974501

  19. DYNAMICAL EVOLUTION AND SPIN-ORBIT RESONANCES OF POTENTIALLY HABITABLE EXOPLANETS: THE CASE OF GJ 581d

    SciTech Connect

    Makarov, Valeri V.; Berghea, Ciprian; Efroimsky, Michael E-mail: ciprian.berghea@usno.navy.mil

    2012-12-20

    GJ 581d is a potentially habitable super-Earth in the multiple system of exoplanets orbiting a nearby M dwarf. We investigate this planet's long-term dynamics with an emphasis on its probable final rotation states acquired via tidal interaction with the host. The published radial velocities for the star are re-analyzed with a benchmark planet detection algorithm to confirm that there is no evidence for the recently proposed two additional planets (f and g). Limiting the scope to the four originally detected planets, we assess the dynamical stability of the system and find bounded chaos in the orbital motion. For the planet d, the characteristic Lyapunov time is 38 yr. Long-term numerical integration reveals that the system of four planets is stable, with the eccentricity of the planet d changing quasi-periodically in a tight range around 0.27, and with its semimajor axis varying only a little. The spin-orbit interaction of GJ 581d with its host star is dominated by the tides exerted by the star on the planet. We model this interaction, assuming a terrestrial composition of the mantle. Besides the triaxiality-caused torque and the secular part of the tidal torque, which are conventionally included in the equation of motion, we also include the tidal torques' oscillating components. It turns out that, depending on the mantle temperature, the planet gets trapped into the 2:1 or an even higher spin-orbit resonance. It is very improbable that the planet could have reached the 1:1 resonance. This improves the possibility of the planet being suitable for sustained life.

  20. Effects of the electron-electron interaction in the spin resonance in 2D systems with Dresselhaus spin-orbit coupling

    SciTech Connect

    Krishtopenko, S. S.

    2015-02-15

    The effect of the electron-electron interaction on the spin-resonance frequency in two-dimensional electron systems with Dresselhaus spin-orbit coupling is investigated. The oscillatory dependence of many-body corrections on the magnetic field is demonstrated. It is shown that the consideration of many-body interaction leads to a decrease or an increase in the spin-resonance frequency, depending on the sign of the g factor. It is found that the term cubic in quasimomentum in Dresselhaus spin-orbit coupling partially decreases exchange corrections to the spin resonance energy in a two-dimensional system.

  1. Zero-conductance resonances and spin polarizations in three-terminal rings in the presence of spin-orbit coupling

    SciTech Connect

    Zhai, Li-Xue; Wang, Yan; Liu, Jian-Jun

    2014-11-28

    Spin dependent transport in one-dimensional (1D) three-terminal rings is investigated in the presence of the Rashba spin-orbit coupling (RSOC). We focus on zero-conductance resonances and spin polarizations. For these purposes, the transmission functions are derived analytically. The total conductances are analyzed in the complex energy plane with a focus on the zero-pole structure characteristic of transmission (anti)resonances. The spin polarizations in symmetrically and asymmetrically coupled three-terminal rings are studied as a function of the incident electron energy. It is found that in the absence of the RSOC there are three kinds of conductance zeros. In the presence of the RSOC, the zeros of the first and the third kinds are lifted, while some of the second kind persist. The lifting of the conductance zeros is related to the breaking of the spin-reversal symmetry, and the lifted conductance zeros evolve into spin polarization zeros.

  2. Simultaneous and Direct Measurement of the Neutron - Branching Ratio of URANIUM-238 in the Region of the Giant Quadrupole Resonance.

    NASA Astrophysics Data System (ADS)

    Countryman, Peter John

    We have measured the coincidence cross-sections ^{238}U(alpha, alpha'{rm n| f} ) and ^{238}U( alpha,alpha'f), and inclusive cross-sections ^{238} U(alpha,alpha') using the 120 MeV alpha particle beam at the Lawrence Berkeley Laboratory's 88-Inch Cyclotron. The (alpha, alpha'{rm n| f} ) experiment simultaneously measured the cross-sections for ^{238}U(alpha, alpha'f) and ^{238 }U(alpha,alpha' {rm n| f}) at theta _{alpha'} ~ 17^circ, a local maximum for the angular distributions of the isoscalar giant quadrupole and monopole resonances (GQ_0R and GM _0R). The branching ratio Gamma _{rm n}/Gamma_{ rm f} obtained from this experiment is therefore not subject to many of the systematic errors which go into the individual cross-sections. The energy of the scattered alpha-particle (E _{alpha'}) and the neutron time-of-flight were measured for each event. Fission events were detected using a large solid-angle array, so that the fission neutrons could be removed from the neutron decay spectra. This enabled us to make the first measurement of the neutron decay from an actinide nucleus. Inelastic scattering cross-sections are presented for the range of excitation energy from 0. to 20. MeV. In a separate experiment, the cross-section {rm d^2sigma(alpha,alpha 'rm f)}over {rm d Omega_{alpha'}{dE}_{alpha'} } was measured for uranium at seven scattering angles in the range theta_{alpha '} = 7^circ -21^{circ}. We extracted the transition strength as a function of excitation energy for the GQ_0R and GM _0R. In (alpha,alpha 'f), we find 25% of the L = 2 energy-weighted sum-rule (from 8 to 12 MeV), and 50% of the L = 0 sum-rule (12 to 16 MeV). The strength agrees well with a recent (e,e^'f) experiment. We used the strengths extracted from the ( alpha,alpha'f) experiment along with the (alpha,alpha' {n| f}) data to place limits on (Gamma_{rm n }/Gamma_{rm f}) _{rm GQR} and ( Gamma_{rm n}/Gamma_ {rm f})_{rm GMR}. We obtained (Gamma_ {rm n}/Gamma_{rm f})_{rm GQR} = 6 +/- 4 (statistical

  3. Giant resonance for the actinide nuclei: Photoneutron and photofission cross sections for /sup 235/U, /sup 236/U, /sup 238/U, and /sup 232/Th

    SciTech Connect

    Caldwell, J.T.; Dowdy, E.J.; Berman, B.L.; Alvarez, R.A.; Meyer, P.

    1980-04-01

    The photoneutron cross sections sigma (..gamma..,n) and sigma (..gamma..,2n), and total photofission cross sections sigma (..gamma..,F) have been measured for /sup 235/U, /sup 236/U, /sup 238/U, and /sup 232/Th from threshold to 18.3 MeV using monoenergetic photons from the annihilation in flight of fast positrons and neutron-multiplicity detection in an efficient 4..pi.. neutron detector. Use of the ring-ratio technique allowed both the average photofission neutron energy for each nucleus to be obtained as a function of photon energy and, for /sup 236/U and /sup 238/U, the determination of the partial cross sections for first-chance sigma (..gamma.., f ) and second-chance sigma (..gamma..,n f ) photofission as well. Information extracted from the data includes integrated cross sections and their moments, giant-resonance parameters, deformation and radius parameters, and relative and absolute neutron and fission probabilities.

  4. Timing Treatment of a Giant Intracranial Aneurysm by the Use of Magnetic Resonance Imaging for the Determination of Intraluminal Clot Stability

    PubMed Central

    Jungreis, Charles A.; Jannetta, Peter J.; Yonas, Howard

    1993-01-01

    A 44-year-old man presented with a giant intracranial carotid artery aneurysm. Magnetic resonance (MR) images demonstrated a large amount of fresh intraluminal thrombus in the aneurysm. During test occlusion of the internal carotid artery using an endovascular balloon positioned in the cervical portion of the internal carotid, the patient sustained an apparent embolic episode. The patient was followed for several weeks with serial MR imaging until the thrombus had lysed. Repeat test occlusion followed by permanent carotid occlusion was uneventful. Serial MR evaluations of intraluminal thrombus in large aneurysms might help to determine an optimal time for institution of intervention. ImagesFigure 1Figure 2Figure 3p34-bFigure 4Figure 5 PMID:17170887

  5. Whispering gallery resonators for studying orbital angular momentum of a photon.

    PubMed

    Matsko, Andrey B; Savchenkov, Anatoliy A; Strekalov, Dmitry; Maleki, Lute

    2005-09-30

    We propose a simple method for generation and detection of photons with nonzero angular momentum. The method utilizes high-quality factor ring resonators that transform a plane electromagnetic wave into a wave with nonzero angular momentum, and vice versa. We show that the method is especially promising for studying high-order Bessel beams, unreachable by other techniques. PMID:16241656

  6. Giant Spin Pumping and Inverse Spin Hall Effect in the Presence of Surface and Bulk Spin-Orbit Coupling of Topological Insulator Bi2Se3.

    PubMed

    Jamali, Mahdi; Lee, Joon Sue; Jeong, Jong Seok; Mahfouzi, Farzad; Lv, Yang; Zhao, Zhengyang; Nikolić, Branislav K; Mkhoyan, K Andre; Samarth, Nitin; Wang, Jian-Ping

    2015-10-14

    Three-dimensional (3D) topological insulators are known for their strong spin-orbit coupling (SOC) and the existence of spin-textured surface states that might be potentially exploited for "topological spintronics." Here, we use spin pumping and the inverse spin Hall effect to demonstrate successful spin injection at room temperature from a metallic ferromagnet (CoFeB) into the prototypical 3D topological insulator Bi2Se3. The spin pumping process, driven by the magnetization dynamics of the metallic ferromagnet, introduces a spin current into the topological insulator layer, resulting in a broadening of the ferromagnetic resonance (FMR) line width. Theoretical modeling of spin pumping through the surface of Bi2Se3, as well as of the measured angular dependence of spin-charge conversion signal, suggests that pumped spin current is first greatly enhanced by the surface SOC and then converted into a dc-voltage signal primarily by the inverse spin Hall effect due to SOC of the bulk of Bi2Se3. We find that the FMR line width broadens significantly (more than a factor of 5) and we deduce a spin Hall angle as large as 0.43 in the Bi2Se3 layer. PMID:26367103

  7. Two-band superfluidity and intrinsic Josephson effect in alkaline-earth-metal Fermi gases across an orbital Feshbach resonance

    NASA Astrophysics Data System (ADS)

    Iskin, M.

    2016-07-01

    We first show that the many-body Hamiltonian governing the physical properties of an alkaline-earth 173Yb Fermi gas across the recently realized orbital Feshbach resonance is exactly analogous to that of two-band s -wave superconductors with contact interactions; i.e., even though the free-particle bands have a tunable energy offset in between and are coupled by a Josephson-type attractive interband pair scattering, the intraband interactions have exactly the same strength. We then introduce two intraband order parameters within the BCS mean-field approximation and investigate the competition between their in-phase and out-of-phase (i.e., the so-called π -phase) solutions in the entire BCS-BEC evolution at zero temperature.

  8. Current-induced spin torque resonance of magnetic insulators affected by field-like spin-orbit torques and out-of-plane magnetizations

    SciTech Connect

    Chiba, Takahiro Takahashi, Saburo; Schreier, Michael; Bauer, Gerrit E. W.

    2015-05-07

    The spin-torque ferromagnetic resonance (ST-FMR) in a bilayer system consisting of a magnetic insulator such as Y{sub 3}Fe{sub 5}O{sub 12} and a normal metal with spin-orbit interaction such as Pt is addressed theoretically. We model the ST-FMR for all magnetization directions and in the presence of field-like spin-orbit torques based on the drift-diffusion spin model and quantum mechanical boundary conditions. ST-FMR experiments may expose crucial information about the spin-orbit coupling between currents and magnetization in the bilayers.

  9. The effect of secular resonances on the long-term orbital evolution of uncontrollable objects on satellite radio navigation systems in the MEO region

    NASA Astrophysics Data System (ADS)

    Bordovitsyna, T. V.; Tomilova, I. V.; Chuvashov, I. N.

    2012-09-01

    We present the results of the study of long-term orbital evolution of space debris objects, formed from end-of-life space vehicles (SV) of satellite radio navigation systems in the medium Earth orbit (MEO) region. Dynamical features of the evolution of objects in this region have been studied on the basis of 20-year laser surveillance with the Etalon-1 and Etalon-2 satellites and the results of numerical simulation of the long-term evolution of operating and disposal orbits of uncontrolled GLONASS and GPS SVs. It is shown that perturbations from secular lunisolar resonances produce an eccentricity growth for orbits with inclinations chosen for navigation constellations; this significantly changes the positions of these orbits in space and results in the ingress of end-of-life objects into the area of operating SVs.

  10. Optically detected magnetic resonance studies of photoexcited /sup 17/O-benzophenone. Orbital rotation in the lowest triplet state

    SciTech Connect

    Waeckerle, G.; Baer, M.; Zimmermann, H.; Dinse, K.H.; Yamauchi, S.; Kashmar, R.J.; Pratt, D.W.

    1982-03-01

    The magnetically active isotope of oxygen /sup 17/O has been used to probe the changes in the electron charge and spin density distributions in oxygen valence orbitals which occur when benzophenone is excited to its lowest triplet state. The data obtained include the optically detected magnetic resonance (ODMR) and electron-nuclear double resonance spectra at both zero and high magnetic fields. New methods of analysis of zero-field ODMR spectra, appropriate when the second-order hyperfine splitting exceeds the quadrupole coupling, are described. This analysis yields the principal values of the electron fine-structure (D), oxygen hyperfine (A), and oxygen quadrupole (Q) tensors, and the orientation of their principal axes with respect to the molecular frame. It is found, consistent with expectations for an n..pi..( state, that the direction of the largest component of Q is different from that of the ground state. It is also found, by two independent methods, that the principal transverse axes of A and Q do not conform to the local C/sub 2v/ symmetry axes of the carbonyl group. This result is interpreted to mean that the axis of the n-type oxygen 2p orbital is rotated out of the carbonyl plane, a rotation which appears to be direct consequence of n..pi..(/..pi pi..( configurational mixing. In agreement with this, the principal values of D, A, and Q are different from those expected for a ''pure'' n..pi..( state. Other consequences of n..pi..(/..pi pi..( mixing, not only in benzophenone but also in the lowest triplet states of other aromatic carbonyls, are discussed briefly.

  11. Aneurysmal bone cyst of the sphenoid with orbital involvement.

    PubMed Central

    Hunter, J. V.; Yokoyama, C.; Moseley, I. F.; Wright, J. E.

    1990-01-01

    We present a case of aneurysmal bone cyst involving the roof of the orbit and sphenoid bone, with plain film, computed tomography, and magnetic resonance imaging findings. The natural history and treatment depend on the presence of associated abnormalities such as fibrous dysplasia or a giant cell tumour. In this case the lesion was solitary and was successfully removed, so that possible complications from radiotherapy were avoided. Images PMID:2202437

  12. Final Version: Orbital Specificity in the Unoccupied States of UO2 from Resonant Inverse Photoelectron Spectroscopy

    SciTech Connect

    Tobin, J G; Yu, S W

    2012-03-12

    One of the crucial questions of all actinide electronic structure determinations is the issue of 5f versus 6d character and the distribution of these components across the density of states. Here, a break-though experiment is discussed, which has allowed the direct determination of the U5f and U6d contributions to the unoccupied density of states (UDOS) in Uranium Dioxide. A novel Resonant Inverse Photoelectron (RIPES) and X-ray Emission Spectroscopy (XES) investigation of UO{sub 2} is presented. It is shown that the U5f and U6d components are isolated and identified unambiguously.

  13. There might be giants: unseen Jupiter-mass planets as sculptors of tightly packed planetary systems

    NASA Astrophysics Data System (ADS)

    Hands, T. O.; Alexander, R. D.

    2016-03-01

    The limited completeness of the Kepler sample for planets with orbital periods ≳1 yr leaves open the possibility that exoplanetary systems may host undetected giant planets. Should such planets exist, their dynamical interactions with the inner planets may prove vital in sculpting the final orbital configurations of these systems. Using an N-body code with additional forces to emulate the effects of a protoplanetary disc, we perform simulations of the assembly of compact systems of super-Earth-mass planets with unseen giant companions. The simulated systems are analogous to Kepler-11 or Kepler-32 in that they contain four or five inner super-Earths, but our systems also contain longer-period giant companions which are unlikely to have been detected by Kepler. We find that giant companions tend to break widely spaced first-order mean-motion resonances, allowing the inner planets to migrate into tighter resonances. This leads to more compact architectures and increases the occurrence rate of Laplace resonant chains.

  14. On the Nature and Timing of Giant Planet Migration in the Solar System

    NASA Astrophysics Data System (ADS)

    Agnor, Craig B.

    2016-05-01

    Giant planet migration is a natural outcome of gravitational scattering and planet formation processes (Fernandez & Ip 1984). There is compelling evidence that the solar system's giant planets experienced large-scale migration involving close approaches between planets as well as smooth radial migration via planetesimal scattering. Aspects of giant planet migration have been invoked to explain many features of the outer solar system including the resonant structure of the Kuiper Belt (e.g., Malhotra 1993, Levison et al. 2008), the eccentricities of Jupiter and Saturn (Tsiganis et al. 2005, Morbidelli et al. 2009), the capture of Jupiter's Trojan companions (Morbidelli et al. 2005) and the capture of irregular planetary satellites (e.g., Nesvorny et al. 2007) to name a few. If this migration epoch occurred after the formation of the inner planets, then it may also explain the so-called lunar Late Heavy Bombardment (Gomes et al. 2005). This scenario necessarily requires coeval terrestrial and migrating giant planets. Recent N-body integrations exploring this issue have shown that giant planet migration may excite the terrestrial system via nodal and apsidal secular resonances (e.g., Brasser et al. 2013), may drive the terrestrial planets to crossing orbits (Kaib & Chambers 2016) or alternatively leave the inner solar system in a state closely resembling the observed one (Roig et al. 2016). The factors accounting for the large range of outcomes remain unclear. Using linear secular models and N-body simulations I am identifying and characterising the principal aspects of giant planet migration that excite the terrestrial planets' orbits. I will present these results and discuss how they inform the nature and timing of giant planet migration in the solar system.

  15. X-ray excited photoluminescence near the giant resonance in solid-solution Gd(1-x)Tb(x)OCl nanocrystals and their retention upon solvothermal topotactic transformation to Gd(1-x)Tb(x)F3.

    PubMed

    Waetzig, Gregory R; Horrocks, Gregory A; Jude, Joshua W; Zuin, Lucia; Banerjee, Sarbajit

    2016-01-14

    Design rules for X-ray phosphors are much less established as compared to their optically stimulated counterparts owing to the absence of a detailed understanding of sensitization mechanisms, activation pathways and recombination channels upon high-energy excitation. Here, we demonstrate a pronounced modulation of the X-ray excited photoluminescence of Tb(3+) centers upon excitation in proximity to the giant resonance of the host Gd(3+) ions in solid-solution Gd1-xTbxOCl nanocrystals prepared by a non-hydrolytic cross-coupling method. The strong suppression of X-ray excited optical luminescence at the giant resonance suggests a change in mechanism from multiple exciton generation to single thermal exciton formation and Auger decay processes. The solid-solution Gd1-xTbxOCl nanocrystals are further topotactically transformed with retention of a nine-coordinated cation environment to solid-solution Gd1-xTbxF3 nanocrystals upon solvothermal treatment with XeF2. The metastable hexagonal phase of GdF3 can be stabilized at room temperature through this topotactic approach and is transformed subsequently to the orthorhombic phase. The fluoride nanocrystals indicate an analogous but blue-shifted modulation of the X-ray excited optical luminescence of the Tb(3+) centers upon X-ray excitation near the giant resonance of the host Gd(3+) ions. PMID:26661920

  16. Low-energy tail of the giant dipole resonance in Mo98 and Mo100 deduced from photon-scattering experiments

    NASA Astrophysics Data System (ADS)

    Rusev, G.; Schwengner, R.; Dönau, F.; Erhard, M.; Grosse, E.; Junghans, A. R.; Kosev, K.; Schilling, K. D.; Wagner, A.; Bečvář, F.; Krtička, M.

    2008-06-01

    Dipole-strength distributions in the nuclides Mo98 and Mo100 up to the neutron-separation energies have been studied in photon-scattering experiments at the bremsstrahlung facility of the Forschungszentrum Dresden-Rossendorf. To determine the dipole-strength distributions up to the neutron-emission thresholds, statistical methods were developed for the analysis of the measured spectra. The measured spectra of scattered photons were corrected for detector response and atomic background by simulations using the code GEANT3. Simulations of γ-ray cascades were performed to correct the intensities of the transitions to the ground state for feeding from higher-lying levels and to determine their branching ratios. The photoabsorption cross sections obtained for Mo98 and Mo100 from the present (γ,γ') experiments are combined with (γ,n) data from literature, resulting in a photoabsorption cross section covering the range from 4 to about 15 MeV of interest for network calculations in nuclear astrophysics. Novel information about the low-energy tail of the giant dipole resonance and its energy dependence is derived. The photoabsorption cross sections deduced from the present photon-scattering experiments are compared with existing data from neutron capture and He3-induced reactions.

  17. Improve the image quality of orbital 3 T diffusion-weighted magnetic resonance imaging with readout-segmented echo-planar imaging.

    PubMed

    Xu, Xiao-Quan; Liu, Jun; Hu, Hao; Su, Guo-Yi; Zhang, Yu-Dong; Shi, Hai-Bin; Wu, Fei-Yun

    2016-01-01

    The aim of our study is to compare the image quality of readout-segmented echo-planar imaging (rs-EPI) and that of standard single-shot EPI (ss-EPI) in orbital 3 T diffusion-weighted (DW) magnetic resonance (MR) imaging in healthy subjects. Forty-two volunteers underwent two sets of orbital DW imaging scan at a 3 T MR unit, and image quality was assessed qualitatively and quantitatively. As a result, we found that rs-EPI could provide better image quality than standard ss-EPI, while no significant difference was found on the apparent diffusion coefficient between the two sets of DW images. PMID:27317226

  18. X-ray resonant scattering studies of charge and orbital ordering in Pr{sub 1{minus}z}, Ca{sub x}, MnO{sub 3}

    SciTech Connect

    V.ZIMMERMANN,M.; NELSON,C.S.; HILL,J.P.; GIBBS,D.; BLUME,M.; CASA,D.; KEIMER,B.; MURAKAMI,Y.; KAO,C.C.; VENKATARAMAN,C.; GOG,T.; TOMIOKA,Y.; TOKURA,Y.

    2000-08-14

    We present the results of x-ray scattering studies of the charge and orbital ordering in the manganite series Pr{sub 1{minus}z}, Ca{sub x}, MnO{sub 3} with x = 0.25, 0.4 and 0.5. The polarization and azimuthal dependence of the charge and orbital ordering in these compounds is characterized both in the resonant and nonresonant limits, and compared with the predictions of current theories. The results are qualitatively consistent with both cluster and LDA+U calculations of the electronic structure.

  19. Quantum states and linear response in dc and electromagnetic fields for the charge current and spin polarization of electrons at the Bi/Si interface with the giant spin-orbit coupling

    SciTech Connect

    Khomitsky, D. V.

    2012-05-15

    An expansion of the nearly free-electron model constructed by Frantzeskakis, Pons, and Grioni [1] describing quantum states at the Bi/Si(111) interface with the giant spin-orbit coupling is developed and applied for the band structure and spin polarization calculation, as well as for the linear response analysis of the charge current and induced spin caused by a dc field and by electromagnetic radiation. It is found that the large spin-orbit coupling in this system may allow resolving the spin-dependent properties even at room temperature and at a realistic collision rate. The geometry of the atomic lattice combined with spin-orbit coupling leads to an anisotropic response for both the current and spin components related to the orientation of the external field. The in-plane dc electric field produces only the in-plane components of spin in the sample, while both the in-plane and out-of-plane spin components can be excited by normally propagating electromagnetic wave with different polarizations.

  20. Localized surface plasmon resonances dominated giant lateral photovoltaic effect observed in ZnO/Ag/Si nanostructure

    NASA Astrophysics Data System (ADS)

    Zhang, Ke; Wang, Hui; Gan, Zhikai; Zhou, Peiqi; Mei, Chunlian; Huang, Xu; Xia, Yuxing

    2016-03-01

    We report substantially enlarged lateral photovoltaic effect (LPE) in the ZnO/Ag/Si nanostructures. The maximum LPE sensitivity (55.05 mv/mm) obtained in this structure is about seven times larger than that observed in the control sample (7.88 mv/mm) of ZnO/Si. We attribute this phenomenon to the strong localized surface plasmon resonances (LSPRs) induced by nano Ag semicontinuous films. Quite different from the traditional LPE in PN junction type structures, in which light-generated carriers contributed to LPE merely depends on direct excitation of light in semiconductor, this work firstly demonstrates that, by introducing a super thin metal Ag in the interface between two different kinds of semiconductors, the nanoscale Ag embedded in the interface will produce strong resonance of localized field, causing extra intraband excitation, interband excitation and an enhanced direct excitation. As a consequence, these LSPRs dominated contributions harvest much more carriers, giving rise to a greatly enhanced LPE. In particular, this LSPRs-driven mechanism constitutes a sharp contrast to the traditional LPE operation mechanism. This work suggests a brand new LSPRs approach for tailoring LPE-based devices and also opens avenues of research within current photoelectric sensors area.

  1. Localized surface plasmon resonances dominated giant lateral photovoltaic effect observed in ZnO/Ag/Si nanostructure.

    PubMed

    Zhang, Ke; Wang, Hui; Gan, Zhikai; Zhou, Peiqi; Mei, Chunlian; Huang, Xu; Xia, Yuxing

    2016-01-01

    We report substantially enlarged lateral photovoltaic effect (LPE) in the ZnO/Ag/Si nanostructures. The maximum LPE sensitivity (55.05 mv/mm) obtained in this structure is about seven times larger than that observed in the control sample (7.88 mv/mm) of ZnO/Si. We attribute this phenomenon to the strong localized surface plasmon resonances (LSPRs) induced by nano Ag semicontinuous films. Quite different from the traditional LPE in PN junction type structures, in which light-generated carriers contributed to LPE merely depends on direct excitation of light in semiconductor, this work firstly demonstrates that, by introducing a super thin metal Ag in the interface between two different kinds of semiconductors, the nanoscale Ag embedded in the interface will produce strong resonance of localized field, causing extra intraband excitation, interband excitation and an enhanced direct excitation. As a consequence, these LSPRs dominated contributions harvest much more carriers, giving rise to a greatly enhanced LPE. In particular, this LSPRs-driven mechanism constitutes a sharp contrast to the traditional LPE operation mechanism. This work suggests a brand new LSPRs approach for tailoring LPE-based devices and also opens avenues of research within current photoelectric sensors area. PMID:26965713

  2. Localized surface plasmon resonances dominated giant lateral photovoltaic effect observed in ZnO/Ag/Si nanostructure

    PubMed Central

    Zhang, Ke; Wang, Hui; Gan, Zhikai; Zhou, Peiqi; Mei, Chunlian; Huang, Xu; Xia, Yuxing

    2016-01-01

    We report substantially enlarged lateral photovoltaic effect (LPE) in the ZnO/Ag/Si nanostructures. The maximum LPE sensitivity (55.05 mv/mm) obtained in this structure is about seven times larger than that observed in the control sample (7.88 mv/mm) of ZnO/Si. We attribute this phenomenon to the strong localized surface plasmon resonances (LSPRs) induced by nano Ag semicontinuous films. Quite different from the traditional LPE in PN junction type structures, in which light-generated carriers contributed to LPE merely depends on direct excitation of light in semiconductor, this work firstly demonstrates that, by introducing a super thin metal Ag in the interface between two different kinds of semiconductors, the nanoscale Ag embedded in the interface will produce strong resonance of localized field, causing extra intraband excitation, interband excitation and an enhanced direct excitation. As a consequence, these LSPRs dominated contributions harvest much more carriers, giving rise to a greatly enhanced LPE. In particular, this LSPRs-driven mechanism constitutes a sharp contrast to the traditional LPE operation mechanism. This work suggests a brand new LSPRs approach for tailoring LPE-based devices and also opens avenues of research within current photoelectric sensors area. PMID:26965713

  3. Spin-orbit coupling in methyl functionalized graphene

    NASA Astrophysics Data System (ADS)

    Zollner, Klaus; Frank, Tobias; Irmer, Susanne; Gmitra, Martin; Kochan, Denis; Fabian, Jaroslav

    2016-01-01

    We present first-principles calculations of the electronic band structure and spin-orbit effects in graphene functionalized with methyl molecules in dense and dilute limits. The dense limit is represented by a 2 ×2 graphene supercell functionalized with one methyl admolecule. The calculated spin-orbit splittings are up to 0.6 meV. The dilute limit is deduced by investigating a large, 7 ×7 , supercell with one methyl admolecule. The electronic band structure of this supercell is fitted to a symmetry-derived effective Hamiltonian, allowing us to extract specific hopping parameters including intrinsic, Rashba, and pseudospin inversion asymmetry spin-orbit terms. These proximity-induced spin-orbit parameters have magnitudes of about 1 meV, giant compared to pristine graphene whose intrinsic spin-orbit coupling is about 10 μ eV . We find that the origin of this giant local enhancement is the s p3 corrugation and the breaking of local pseudospin inversion symmetry, as in the case of hydrogen adatoms. Similarly to hydrogen, also methyl acts as a resonant scatterer, with a narrow resonance peak near the charge neutrality point. We also calculate STM-like images showing the local charge densities at different energies around methyl on graphene.

  4. Evolutionary outcomes for pairs of planets undergoing orbital migration and circularization: second-order resonances and observed period ratios in Kepler's planetary systems

    NASA Astrophysics Data System (ADS)

    Xiang-Gruess, M.; Papaloizou, J. C. B.

    2015-05-01

    In order to study the origin of the architectures of low-mass planetary systems, we perform numerical surveys of the evolution of pairs of coplanar planets in the mass range (1-4) M⊕. These evolve for up to 2 × 107 yr under a range of orbital migration torques and circularization rates assumed to arise through interaction with a protoplanetary disc. Near the inner disc boundary, significant variations of viscosity, interaction with density waves or with the stellar magnetic field could occur and halt migration, but allow circularization to continue. This was modelled by modifying the migration and circularization rates. Runs terminated without an extended period of circularization in the absence of migration torques gave rise to either a collision, or a system close to a resonance. These were mostly first order with a few per cent terminating in second-order resonances. Both planetary eccentricities were small <0.1 and all resonant angles liberated. This type of survey produced only a limited range of period ratios and cannot reproduce Kepler observations. When circularization alone operates in the final stages, divergent migration occurs causing period ratios to increase. Depending on its strength the whole period ratio range between 1 and 2 can be obtained. A few systems close to second-order commensurabilities also occur. In contrast to when arising through convergent migration, resonant trapping does not occur and resonant angles circulate. Thus, the behaviour of the resonant angles may indicate the form of migration that led to near resonance.

  5. Delocalization and occupancy effects of 5f orbitals in plutonium intermetallics using L3-edge resonant X-ray emission spectroscopy

    SciTech Connect

    Booth, C. H.; Medling, S. A.; Jiang, Yu; Bauer, E. D.; Tobash, P. H.; Mitchell, J. N.; Veirs, D. K.; Wall, M. A.; Allen, P. G.; Kas, J. J.; Sokaras, D.; Nordlund, D.; Weng, T. -C.

    2014-06-24

    Although actinide (An) L3 -edge X-ray absorption near-edge structure (XANES) spectroscopy has been very effective in determining An oxidation states in insulating, ionically bonded materials, such as in certain coordination compounds and mineral systems, the technique fails in systems featuring more delocalized 5f orbitals, especially in metals. Recently, actinide L3-edge resonant X-ray emission spec- troscopy (RXES) has been shown to be an effective alternative. This technique is further demonstrated here using a parameterized partial unoccupied density of states method to quantify both occupancy and delocalization of the 5f orbital in ?-Pu, ?-Pu, PuCoGa5 , PuCoIn5 , and PuSb2. These new results, supported by FEFF calculations, highlight the effects of strong correlations on RXES spectra and the technique?s ability to differentiate between f-orbital occupation and delocalization.

  6. Orbital Evolution of Asteroids

    NASA Astrophysics Data System (ADS)

    Dermott, S. F.; Kehoe, T. J. J.

    2011-10-01

    The synthetic orbital frequencies and eccentricities of main belt asteroids computed by Knezevic and Milani [2] show evidence that the structure of the asteroid belt has been determined by a dense of web of high-order resonances. By examining the orbital frequency distribution at high resolution, we discover a correlation between asteroid number density, mean orbital eccentricity and Lyapunov Characteristic Exponent. In particular, the orbital eccentricities of asteroids trapped in resonance tend to be higher than those of non-resonant asteroids and we argue that this is observational evidence for orbital evolution due to chaotic diffusion.

  7. LONG RANGE OUTWARD MIGRATION OF GIANT PLANETS, WITH APPLICATION TO FOMALHAUT b

    SciTech Connect

    Crida, Aurelien; Masset, Frederic

    2009-11-10

    Recent observations of exoplanets by direct imaging reveal that giant planets orbit at a few dozens to more than a hundred AU from their central star. The question of the origin of these planets challenges the standard theories of planet formation. We propose a new way of obtaining such far planets, by outward migration of a pair of planets formed in the 10 AU region. Two giant planets in mean motion resonance in a common gap in the protoplanetary disk migrate outward, if the inner one is significantly more massive than the outer one. Using hydrodynamical simulations, we show that their semimajor axes can increase by almost 1 order of magnitude. In a flared disk, the pair of planets should reach an asymptotic radius. This mechanism could account for the presence of Fomalhaut b; then, a second, more massive planet, should be orbiting Fomalhaut at about 75 AU.

  8. Orbits Around Black Holes in Triaxial Nuclei

    NASA Astrophysics Data System (ADS)

    Merritt, David; Vasiliev, Eugene

    2011-01-01

    We discuss the properties of orbits within the influence sphere of a supermassive black hole (BH), in the case that the surrounding star cluster is non-axisymmetric. There are four major orbit families; one of these, the pyramid orbits, have the interesting property that they can approach arbitrarily closely to the BH. We derive the orbit-averaged equations of motion and show that in the limit of weak triaxiality, the pyramid orbits are integrable: the motion consists of a two-dimensional libration of the major axis of the orbit about the short axis of the triaxial figure, with eccentricity varying as a function of the two orientation angles and reaching unity at the corners. Because pyramid orbits occupy the lowest angular momentum regions of phase space, they compete with collisional loss cone repopulation and with resonant relaxation (RR) in supplying matter to BHs. General relativistic advance of the periapse dominates the precession for sufficiently eccentric orbits, and we show that relativity imposes an upper limit to the eccentricity: roughly the value at which the relativistic precession time is equal to the time for torques to change the angular momentum. We argue that this upper limit to the eccentricity should also apply to evolution driven by RR, with potentially important consequences for the rate of extreme-mass-ratio inspirals in low-luminosity galaxies. In giant galaxies, we show that capture of stars on pyramid orbits can dominate the feeding of BHs, at least until such a time as the pyramid orbits are depleted; however this time can be of order a Hubble time.

  9. ORBITS AROUND BLACK HOLES IN TRIAXIAL NUCLEI

    SciTech Connect

    Merritt, David; Vasiliev, Eugene E-mail: eugvas@lpi.ru

    2011-01-10

    We discuss the properties of orbits within the influence sphere of a supermassive black hole (BH), in the case that the surrounding star cluster is non-axisymmetric. There are four major orbit families; one of these, the pyramid orbits, have the interesting property that they can approach arbitrarily closely to the BH. We derive the orbit-averaged equations of motion and show that in the limit of weak triaxiality, the pyramid orbits are integrable: the motion consists of a two-dimensional libration of the major axis of the orbit about the short axis of the triaxial figure, with eccentricity varying as a function of the two orientation angles and reaching unity at the corners. Because pyramid orbits occupy the lowest angular momentum regions of phase space, they compete with collisional loss cone repopulation and with resonant relaxation (RR) in supplying matter to BHs. General relativistic advance of the periapse dominates the precession for sufficiently eccentric orbits, and we show that relativity imposes an upper limit to the eccentricity: roughly the value at which the relativistic precession time is equal to the time for torques to change the angular momentum. We argue that this upper limit to the eccentricity should also apply to evolution driven by RR, with potentially important consequences for the rate of extreme-mass-ratio inspirals in low-luminosity galaxies. In giant galaxies, we show that capture of stars on pyramid orbits can dominate the feeding of BHs, at least until such a time as the pyramid orbits are depleted; however this time can be of order a Hubble time.

  10. The role of orbital dynamics and cloud-cloud collisions in the formation of giant molecular clouds in global spiral structures

    NASA Technical Reports Server (NTRS)

    Roberts, William W., Jr.; Stewart, Glen R.

    1987-01-01

    The role of orbit crowding and cloud-cloud collisions in the formation of GMCs and their organization in global spiral structure is investigated. Both N-body simulations of the cloud system and a detailed analysis of individual particle orbits are used to develop a conceptual understanding of how individual clouds participate in the collective density response. Detailed comparisons are made between a representative cloud-particle simulation in which the cloud particles collide inelastically with one another and give birth to and subsequently interact with young star associations and stripped down simulations in which the cloud particles are allowed to follow ballistic orbits in the absence of cloud-cloud collisions or any star formation processes. Orbit crowding is then related to the behavior of individual particle trajectories in the galactic potential field. The conceptual picture of how GMCs are formed in the clumpy ISMs of spiral galaxies is formulated, and the results are compared in detail with those published by other authors.

  11. X-ray excited photoluminescence near the giant resonance in solid-solution Gd1-xTbxOCl nanocrystals and their retention upon solvothermal topotactic transformation to Gd1-xTbxF3

    NASA Astrophysics Data System (ADS)

    Waetzig, Gregory R.; Horrocks, Gregory A.; Jude, Joshua W.; Zuin, Lucia; Banerjee, Sarbajit

    2015-12-01

    Design rules for X-ray phosphors are much less established as compared to their optically stimulated counterparts owing to the absence of a detailed understanding of sensitization mechanisms, activation pathways and recombination channels upon high-energy excitation. Here, we demonstrate a pronounced modulation of the X-ray excited photoluminescence of Tb3+ centers upon excitation in proximity to the giant resonance of the host Gd3+ ions in solid-solution Gd1-xTbxOCl nanocrystals prepared by a non-hydrolytic cross-coupling method. The strong suppression of X-ray excited optical luminescence at the giant resonance suggests a change in mechanism from multiple exciton generation to single thermal exciton formation and Auger decay processes. The solid-solution Gd1-xTbxOCl nanocrystals are further topotactically transformed with retention of a nine-coordinated cation environment to solid-solution Gd1-xTbxF3 nanocrystals upon solvothermal treatment with XeF2. The metastable hexagonal phase of GdF3 can be stabilized at room temperature through this topotactic approach and is transformed subsequently to the orthorhombic phase. The fluoride nanocrystals indicate an analogous but blue-shifted modulation of the X-ray excited optical luminescence of the Tb3+ centers upon X-ray excitation near the giant resonance of the host Gd3+ ions.Design rules for X-ray phosphors are much less established as compared to their optically stimulated counterparts owing to the absence of a detailed understanding of sensitization mechanisms, activation pathways and recombination channels upon high-energy excitation. Here, we demonstrate a pronounced modulation of the X-ray excited photoluminescence of Tb3+ centers upon excitation in proximity to the giant resonance of the host Gd3+ ions in solid-solution Gd1-xTbxOCl nanocrystals prepared by a non-hydrolytic cross-coupling method. The strong suppression of X-ray excited optical luminescence at the giant resonance suggests a change in mechanism

  12. Asteroid 2015 DB216: a recurring co-orbital companion to Uranus

    NASA Astrophysics Data System (ADS)

    de la Fuente Marcos, C.; de la Fuente Marcos, R.

    2015-10-01

    Minor bodies trapped in 1:1 co-orbital resonances with a host planet could be relevant to explain the origin of captured satellites. Among the giant planets, Uranus has one of the smallest known populations of co-orbitals, three objects, and all of them are short-lived. Asteroid 2015 DB216 has an orbital period that matches well that of Uranus, and here we investigate its dynamical state. Direct N-body calculations are used to assess the current status of this object, reconstruct its immediate dynamical past, and explore its future orbital evolution. A covariance matrix-based Monte Carlo scheme is presented and applied to study its short-term stability. We find that 2015 DB216 is trapped in a temporary co-orbital resonance with Uranus, the fourth known minor body to do so. A detailed analysis of its dynamical evolution shows that it is an unstable but recurring co-orbital companion to Uranus. It currently follows an asymmetric horseshoe trajectory that will last for at least 10 kyr, but it may remain inside Uranus' co-orbital zone for millions of years. As in the case of other transient Uranian co-orbitals, complex multibody ephemeral mean motion resonances trigger the switching between the various resonant co-orbital states. The new Uranian co-orbital exhibits a secular behaviour markedly different from that of the other known Uranian co-orbitals because of its higher inclination, nearly 38°. Given its rather unusual discovery circumstances, the presence of 2015 DB216 hints at the existence of a relatively large population of objects moving in similar orbits.

  13. Nuclear magnetic resonance chemical shifts with the statistical average of orbital-dependent model potentials in Kohn-Sham density functional theory

    NASA Astrophysics Data System (ADS)

    Poater, Jordi; van Lenthe, Erik; Baerends, Evert Jan

    2003-05-01

    In this paper, an orbital-dependent Kohn-Sham exchange-correlation potential, the so-called statistical average of (model) orbital potentials, is applied to the calculation of nuclear magnetic resonance chemical shifts of a series of simple molecules containing H, C, N, O, and F. It is shown that the use of this model potential leads to isotropic chemical shifts which are substantially improved over both local and gradient-corrected functionals, especially for nitrogen and oxygen atoms. This improvement in the chemical shift calculations can be attributed to the increase in the gap between highest occupied and lowest unoccupied orbitals, thus correcting the excessively large paramagnetic contributions, which have been identified to give deficient chemical shifts with both the local-density approximation and with gradient-corrected functionals. This is in keeping with the improvement by the statitical average of orbital model potentials for response properties in general and for excitation energies in particular. The present results are comparable in accuracy to those previously reported with self-interaction corrected functionals by Patchovskii et al., but still inferior to those obtained with accurate Kohn-Sham potentials by Wilson and Tozer. However, the present approach is computationally expedient and routinely applicable to all systems, requiring virtually the same computational effort as local-density and generalized-gradient calculations.

  14. A resonant chain of four transiting, sub-Neptune planets

    NASA Astrophysics Data System (ADS)

    Mills, Sean M.; Fabrycky, Daniel C.; Migaszewski, Cezary; Ford, Eric B.; Petigura, Erik; Isaacson, Howard

    2016-05-01

    Surveys have revealed many multi-planet systems containing super-Earths and Neptunes in orbits of a few days to a few months. There is debate whether in situ assembly or inward migration is the dominant mechanism of the formation of such planetary systems. Simulations suggest that migration creates tightly packed systems with planets whose orbital periods may be expressed as ratios of small integers (resonances), often in a many-planet series (chain). In the hundreds of multi-planet systems of sub-Neptunes, more planet pairs are observed near resonances than would generally be expected, but no individual system has hitherto been identified that must have been formed by migration. Proximity to resonance enables the detection of planets perturbing each other. Here we report transit timing variations of the four planets in the Kepler-223 system, model these variations as resonant-angle librations, and compute the long-term stability of the resonant chain. The architecture of Kepler-223 is too finely tuned to have been formed by scattering, and our numerical simulations demonstrate that its properties are natural outcomes of the migration hypothesis. Similar systems could be destabilized by any of several mechanisms, contributing to the observed orbital-period distribution, where many planets are not in resonances. Planetesimal interactions in particular are thought to be responsible for establishing the current orbits of the four giant planets in the Solar System by disrupting a theoretical initial resonant chain similar to that observed in Kepler-223.

  15. A resonant chain of four transiting, sub-Neptune planets.

    PubMed

    Mills, Sean M; Fabrycky, Daniel C; Migaszewski, Cezary; Ford, Eric B; Petigura, Erik; Isaacson, Howard

    2016-05-26

    Surveys have revealed many multi-planet systems containing super-Earths and Neptunes in orbits of a few days to a few months. There is debate whether in situ assembly or inward migration is the dominant mechanism of the formation of such planetary systems. Simulations suggest that migration creates tightly packed systems with planets whose orbital periods may be expressed as ratios of small integers (resonances), often in a many-planet series (chain). In the hundreds of multi-planet systems of sub-Neptunes, more planet pairs are observed near resonances than would generally be expected, but no individual system has hitherto been identified that must have been formed by migration. Proximity to resonance enables the detection of planets perturbing each other. Here we report transit timing variations of the four planets in the Kepler-223 system, model these variations as resonant-angle librations, and compute the long-term stability of the resonant chain. The architecture of Kepler-223 is too finely tuned to have been formed by scattering, and our numerical simulations demonstrate that its properties are natural outcomes of the migration hypothesis. Similar systems could be destabilized by any of several mechanisms, contributing to the observed orbital-period distribution, where many planets are not in resonances. Planetesimal interactions in particular are thought to be responsible for establishing the current orbits of the four giant planets in the Solar System by disrupting a theoretical initial resonant chain similar to that observed in Kepler-223. PMID:27225123

  16. The Origin of Pluto's Orbit: Implications for the Solar System Beyond Neptune

    NASA Technical Reports Server (NTRS)

    Malhotra, Renu

    1995-01-01

    The origin of the highly eccentric, inclined, and resonance-locked orbit of Pluto has long been a puzzle. A possible explanation has been proposed recently which suggests that these extraordinary orbital properties may be a natural consequence of the formation and early dynamical evolution of the outer solar system. A resonance capture mechanism is possible during the clearing of the residual planetesimal debris and the formation of the Oort Cloud of comets by planetesimal mass loss from the vicinity of the giant planets. If this mechanism were in operation during the early history of the planetary system, the entire region between the orbit of Neptune and approximately 50 AU would have been swept by first-order mean motion resonances. Thus, resonance capture could occur not only for Pluto, but quite generally for other trans-Neptunian small bodies. Some consequences of this evolution for the present-day dynamical structure of the trans-Neptunian region are (1) most of the objects in the region beyond Neptune and up to approximately 50 AU exist in very narrow zones located at orbital resonances with Neptune (particularly the 3:2 and the 2:1 resonances); and (2) these resonant objects would have significantly large eccentricities. The distribution of objects in the Kuiper Belt as predicted by this theory is presented here.

  17. Study of leading strange meson resonances and spin-orbit splittings in K/sup -/p. -->. K/sup -/. pi. /sup +/n at 11 GeV/c

    SciTech Connect

    Honma, A.K.

    1980-11-01

    The results from a high-statistics study of K..pi.. elastic scattering in the reaction K/sup -/p ..-->.. K/sup -/..pi../sup +/n are presented. The data for this analysis are taken from an 11-GeV/c K/sup -/p experiment performed on the Large Aperture Solenoidal Spectrometer (LASS) facility at the Stanford Linear Accelerator Center (SLAC). By selecting the very forward produced K/sup -/..pi../sup +/ events, a sample consisting of data for the K..pi.. ..-->.. K..pi.. elastic scattering reaction was extracted. The angular distribution for this meson-meson scattering is studied by use of both a spherical harmonic moments analysis and a partial-wave analysis (PWA). The previously established leading natural spin-parity strange meson resonances (the J/sup P/ = 1/sup -/ K*(895), the 2/sup +/ K*(1430), and the 3/sup -/ K*(1780)) are observed in the results from both the moments analysis and the PWA. In addition, evidence for a new spin 4/sup -/ K* resonance with a mass of 2080 MeV and a width of about 225 MeV is presented. The results from the PWA confirm the existence of a 0/sup +/ kappa (1490) and propose the existence of a second scalar meson resonance, the 0/sup +/ kappa' (1900). Structure in the P-wave amplitude indicates resonance behavior in the mass region near 1700 MeV. In two of the four ambiguous solutions for the mass region above 1800 MeV, there is strong evidence for another P-wave resonant structure near 2100 MeV. The observed strange meson resonances are found to have a natural interpretation in terms of states predicted by the quark model. In particular, the mass splittings of the leading trajectory natural spin-parity strange meson states and the mass splittings between the spin-orbit triplet states are discussed. 59 figures, 17 tables.

  18. Exploring Atmospheres of Hot Mini-Neptunes and Extrasolar Giant Planets Orbiting Different Stars with Application to HD 97658b, WASP-12b, CoRoT-2b, XO-1b, and HD 189733b

    NASA Astrophysics Data System (ADS)

    Miguel, Y.; Kaltenegger, L.

    2014-01-01

    We calculated an atmospheric grid for hot mini-Neptune and giant exoplanets that links astrophysical observable parameters—orbital distance and stellar type—with the chemical atmospheric species expected. The grid can be applied to current and future observations to characterize exoplanet atmospheres and serves as a reference to interpret atmospheric retrieval analysis results. To build the grid, we developed a one-dimensional code for calculating the atmospheric thermal structure and linked it to a photochemical model that includes disequilibrium chemistry (molecular diffusion, vertical mixing, and photochemistry). We compare the thermal profiles and atmospheric composition of planets at different semimajor axes (0.01 AU <= a <= 0.1 AU) orbiting F, G, K, and M stars. Temperature and UV flux affect chemical species in the atmosphere. We explore which effects are due to temperature and which are due to stellar characteristics, showing the species most affected in each case. CH4 and H2O are the most sensitive to UV flux, H displaces H2 as the most abundant gas in the upper atmosphere for planets receiving a high UV flux. CH4 is more abundant for cooler planets. We explore vertical mixing, to inform degeneracies on our models and in the resulting spectral observables. For lower pressures, observable species like H2O or CO2 can indicate the efficiency of vertical mixing, with larger mixing ratios for a stronger mixing. By establishing the grid, testing the sensitivity of the results, and comparing our model to published results, our paper provides a tool to estimate what observations could yield. We apply our model to WASP-12b, CoRoT-2b, XO-1b, HD189733b, and HD97658b.

  19. Exploring atmospheres of hot mini-Neptune and extrasolar giant planets orbiting different stars with application to HD 97658b, WASP-12b, CoRoT-2b, XO-1b, and HD 189733b

    SciTech Connect

    Miguel, Y.; Kaltenegger, L.

    2014-01-10

    We calculated an atmospheric grid for hot mini-Neptune and giant exoplanets that links astrophysical observable parameters—orbital distance and stellar type—with the chemical atmospheric species expected. The grid can be applied to current and future observations to characterize exoplanet atmospheres and serves as a reference to interpret atmospheric retrieval analysis results. To build the grid, we developed a one-dimensional code for calculating the atmospheric thermal structure and linked it to a photochemical model that includes disequilibrium chemistry (molecular diffusion, vertical mixing, and photochemistry). We compare the thermal profiles and atmospheric composition of planets at different semimajor axes (0.01 AU ≤ a ≤ 0.1 AU) orbiting F, G, K, and M stars. Temperature and UV flux affect chemical species in the atmosphere. We explore which effects are due to temperature and which are due to stellar characteristics, showing the species most affected in each case. CH{sub 4} and H{sub 2}O are the most sensitive to UV flux, H displaces H{sub 2} as the most abundant gas in the upper atmosphere for planets receiving a high UV flux. CH{sub 4} is more abundant for cooler planets. We explore vertical mixing, to inform degeneracies on our models and in the resulting spectral observables. For lower pressures, observable species like H{sub 2}O or CO{sub 2} can indicate the efficiency of vertical mixing, with larger mixing ratios for a stronger mixing. By establishing the grid, testing the sensitivity of the results, and comparing our model to published results, our paper provides a tool to estimate what observations could yield. We apply our model to WASP-12b, CoRoT-2b, XO-1b, HD189733b, and HD97658b.

  20. Statistical Study of the Early Solar System's Instability with Four, Five, and Six Giant Planets

    NASA Astrophysics Data System (ADS)

    Nesvorný, David; Morbidelli, Alessandro

    2012-10-01

    Several properties of the solar system, including the wide radial spacing and orbital eccentricities of giant planets, can be explained if the early solar system evolved through a dynamical instability followed by migration of planets in the planetesimal disk. Here we report the results of a statistical study, in which we performed nearly 104 numerical simulations of planetary instability starting from hundreds of different initial conditions. We found that the dynamical evolution is typically too violent, if Jupiter and Saturn start in the 3:2 resonance, leading to ejection of at least one ice giant from the solar system. Planet ejection can be avoided if the mass of the transplanetary disk of planetesimals was large (M disk >~ 50 M Earth), but we found that a massive disk would lead to excessive dynamical damping (e.g., final e 55 <~ 0.01 compared to present e 55 = 0.044, where e 55 is the amplitude of the fifth eccentric mode in the Jupiter's orbit), and to smooth migration that violates constraints from the survival of the terrestrial planets. Better results were obtained when the solar system was assumed to have five giant planets initially, and one ice giant, with mass comparable to that of Uranus and Neptune, was ejected into interstellar space by Jupiter. The best results were obtained when the ejected planet was placed into the external 3:2 or 4:3 resonance with Saturn and M disk ~= 20 M Earth. The range of possible outcomes is rather broad in this case, indicating that the present solar system is neither a typical nor expected result for a given initial state, and occurs, in best cases, with only a sime5% probability (as defined by the success criteria described in the main text). The case with six giant planets shows interesting dynamics but does offer significant advantages relative to the five-planet case.

  1. The Primordial Destruction of Moons around Giant Exoplanets through Disk-Driven Planetary Migration

    NASA Astrophysics Data System (ADS)

    Spalding, Christopher; Batygin, Konstantin; Adams, Fred C.

    2015-11-01

    The extensive array of satellites around Jupiter and Saturn makes it reasonable to suspect that similar systems of moons might exist around giant extrasolar planets. Observational surveys have revealed a significant population of such giant planets residing at distances of about 1 AU, leading to speculation that some of these 'exomoons' might be capable of maintaining liquid water on their surfaces. Accordingly, many recent efforts have specifically hunted for moons around giant exoplanets. Owing to the lack of detections thus far, it is worth asking whether certain processes intrinsic to planet formation might lead to the loss of moons. Here, we highlight that giant planets are thought to undergo inward migration within their natal disks and show that the very process of migration naturally captures moons into a so-called "evection resonance". Within this resonance, the lunar orbit's eccentricity grows until the moon is lost, either by collision with the planet or through tidal disruption. Whether moons survive or not is critically dependent upon where the planet began its inward trek. In this way, the presence or absence of exomoons can inform us on the extent of inward migration, for which no reliable observational proxy currently exists.

  2. Resonance

    NASA Astrophysics Data System (ADS)

    Perozzi, E.; Murdin, P.

    2000-11-01

    A resonance in CELESTIAL MECHANICS occurs when some of the quantities characterizing the motion of two or more celestial bodies can be considered as commensurable, i.e. their ratio is close to an integer fraction. In a simplified form, this can be expressed as ...

  3. Kuiper Prize: Giant Planet Atmospheres

    NASA Astrophysics Data System (ADS)

    Ingersoll, Andrew P.

    2007-10-01

    The study of giant planet atmospheres is near and dear to me, for several reasons. First, the giant planets are photogenic; the colored clouds are great tracers, and one can make fantastic movies of the atmosphere in motion. Second, the giant planets challenge us with storms that last for hundreds of years and winds that blow faster the farther you go from the sun. Third, they remind us of Earth with their hurricanes, auroras, and lightning, but they also are the link to the 200 giant planets that have been discovered around other stars. This talk will cover the past, present, and future (one hopes) of giant planet research. I will review the surprises of the Voyager and Galileo eras, and will discuss what we are learning now from the Cassini orbiter. I will review the prospects for answering the outstanding questions like: Where's the water? What is providing the colors of the clouds? How deep do the features extend? Where do the winds get their energy? What is the role of the magnetic field? Finally, I will briefly discuss how extrasolar giant planets compare with objects in our own solar system.

  4. Orbital perturbations of the Galilean satellites during planetary encounters

    SciTech Connect

    Deienno, Rogerio; Nesvorný, David; Vokrouhlický, David; Yokoyama, Tadashi

    2014-08-01

    The Nice model of the dynamical instability and migration of the giant planets can explain many properties of the present solar system, and can be used to constrain its early architecture. In the jumping-Jupiter version of the Nice model, required from the terrestrial planet constraint and dynamical structure of the asteroid belt, Jupiter has encounters with an ice giant. Here, we study the survival of the Galilean satellites in the jumping-Jupiter model. This is an important concern because the ice-giant encounters, if deep enough, could dynamically perturb the orbits of the Galilean satellites and lead to implausible results. We performed numerical integrations where we tracked the effect of planetary encounters on the Galilean moons. We considered three instability cases from Nesvorný and Morbidelli that differed in the number and distribution of encounters. We found that in one case, where the number of close encounters was relatively small, the Galilean satellite orbits were not significantly affected. In the other two, the orbital eccentricities of all moons were excited by encounters, Callisto's semimajor axis changed, and, in a large fraction of trials, the Laplace resonance of the inner three moons was disrupted. The subsequent evolution by tides damps eccentricities and can recapture the moons in the Laplace resonance. A more important constraint is represented by the orbital inclinations of the moons, which can be excited during the encounters and not appreciably damped by tides. We find that one instability case taken from Nesvorný and Morbidelli clearly does not meet this constraint. This shows how the regular satellites of Jupiter can be used to set limits on the properties of encounters in the jumping-Jupiter model, and help us to better understand how the early solar system evolved.

  5. Hot super-Earths and giant planet cores from different migration histories

    NASA Astrophysics Data System (ADS)

    Cossou, Christophe; Raymond, Sean N.; Hersant, Franck; Pierens, Arnaud

    2014-09-01

    Planetary embryos embedded in gaseous protoplanetary disks undergo Type I orbital migration. Migration can be inward or outward depending on the local disk properties but, in general, only planets more massive than several M⊕ can migrate outward. Here we propose that an embryo's migration history determines whether it becomes a hot super-Earth or the core of a giant planet. Systems of hot super-Earths (or mini-Neptunes) form when embryos migrate inward and pile up at the inner edge of the disk. Giant planet cores form when inward-migrating embryos become massive enough to switch direction and migrate outward. We present simulations of this process using a modified N-body code, starting from a swarm of planetary embryos. Systems of hot super-Earths form in resonant chains with the innermost planet at or interior to the disk inner edge. Resonant chains are disrupted by late dynamical instabilities triggered by the dispersal of the gaseous disk. Giant planet cores migrate outward toward zero-torque zones, which move inward and eventually disappear as the disk disperses. Giant planet cores migrate inward with these zones and are stranded at ~1-5 AU. Our model reproduces several properties of the observed extra-solar planet populations. The frequency of giant planet cores increases strongly when the mass in solids is increased, consistent with the observed giant exoplanet - stellar metallicity correlation. The frequency of hot super-Earths is not a function of stellar metallicity, also in agreement with observations. Our simulations can reproduce the broad characteristics of the observed super-Earth population.

  6. Resonant inelastic x-ray scattering study of entangled spin-orbital excitations in superconducting PrFeAsO0.7

    NASA Astrophysics Data System (ADS)

    Nomura, T.; Harada, Y.; Niwa, H.; Ishii, K.; Ishikado, M.; Shamoto, S.; Jarrige, I.

    2016-07-01

    Low-energy electron excitation spectra were measured on a single crystal of a typical iron-based superconductor PrFeAsO0.7 using resonant inelastic x-ray scattering (RIXS) at the Fe -L3 edge. Characteristic RIXS features are clearly observed around 0.5, 1-1.5, and 2-3 eV energy losses. These excitations are analyzed microscopically with theoretical calculations using a 22-orbital model derived from first-principles electronic structure calculation. Based on the agreement with the experiment, the RIXS features are assigned to Fe-d orbital excitations which, at low energies, are accompanied by spin flipping and dominated by Fe dy z and dx z orbital characters. Furthermore, our calculations suggest dispersive momentum dependence of the RIXS excitations below 0.5 eV, and predict remarkable splitting and merging of the lower-energy excitations in momentum space. Those excitations, which were not observed in the present experiment, highlight the potential of RIXS with an improved energy resolution to unravel new details of the electronic structure of the iron-based superconductors.

  7. Wandering Gas Giants and Lunar Bombardment

    NASA Astrophysics Data System (ADS)

    Taylor, G. J.

    2006-08-01

    There may have been a dramatic event early in the history of the Solar System--the intense bombardment of the inner planets and the Moon by planetesimals during a narrow interval between 3.92 and 3.85 billion years ago, called the late heavy bombardment, but also nicknamed the lunar cataclysm. The evidence for this event comes from Apollo lunar samples and lunar meteorites. While not proven, it makes for an interesting working hypothesis. If correct, what caused it to happen? A group of physicists from the Observatoire de la Côte d'Azur (Nice, France), GEA/OV/Universidade Federal do Rio de Janeiro and Observatorio Nacional/MTC (Rio de Janeiro, Brazil), and the Southwest Research Institute (Boulder, Colorado) conducted a series of studies of the dynamics of the early Solar System. Alessandro Morbidelli, Kleomenis Tsiganis, Rodney Gomes, and Harold Levison simulated the migration of Saturn and Jupiter. When the orbits of these giant planets reached the special condition of Saturn making one trip around the Sun for every two trips by Jupiter (called the 1:2 resonance), violent gravitational shoves made the orbits of Neptune and Uranus unstable, causing them to migrate rapidly and scatter countless planetesimals throughout the Solar System. This dramatic event could have happened in a short interval, anywhere from 200 million years to a billion years after planet formation, causing the lunar cataclysm, which would have affected all the inner planets.

  8. Exotic Earths: forming habitable worlds with giant planet migration.

    PubMed

    Raymond, Sean N; Mandell, Avi M; Sigurdsson, Steinn

    2006-09-01

    Close-in giant planets (e.g., "hot Jupiters") are thought to form far from their host stars and migrate inward, through the terrestrial planet zone, via torques with a massive gaseous disk. Here we simulate terrestrial planet growth during and after giant planet migration. Several-Earth-mass planets also form interior to the migrating jovian planet, analogous to recently discovered "hot Earths." Very-water-rich, Earth-mass planets form from surviving material outside the giant planet's orbit, often in the habitable zone and with low orbital eccentricities. More than a third of the known systems of giant planets may harbor Earth-like planets. PMID:16960000

  9. Sizing Up Red-Giant Twins

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-02-01

    In KIC 9246715, two red-giant stars twins in nearly every way circle each other in a 171-day orbit. This binary pair may be a key to learning about masses and radii of stars with asteroseismology, the study of oscillations in the interiors of stars.Two Ways to MeasureIn order to understand a stars evolution, it is critical that we know its mass and radius. Unfortunately, these quantities are often difficult to pin down!One of the few cases in which we can directly measure stars masses and radii is in eclipsing binaries, wherein two stars eclipse each other as they orbit. If we have a well-sampled light curve for the binary, as well as radial velocities for both stars, then we can determine the stars complete orbital information, including their masses and radii.But there may be another way to obtain stellar mass and radius: asteroseismology. In asteroseismology, oscillations inside stars are used to characterize the stellar interiors. Conveniently, if a star with a convective envelope exhibits solar-like oscillations, these oscillations can be directly compared to those of the Sun. Mass and radius scaling relations which use the Sun as a benchmark and scale based on the stars temperature can then be used to derive the mass and radius of the star.Test Subjects from KeplerSolar-like oscillations from KIC 9246715 are shown in red across different resonant frequencies. The oscillations of a single red-giant star with similar properties are shown upside down in grey for reference. [Rawls et al. 2016]Of course, scaling relations are only useful if we can test them! A team of scientists including Meredith Rawls (New Mexico State University) has identified 18 red-giant eclipsing binaries in the Kepler field of view that also exhibit solar-like oscillations perfect for testing the scaling relations.In a recent study led by Rawls, the team analyzed the first of these binaries, KIC 9246715. Using the Kepler light curves in addition to radial velocity measurements from high

  10. Giant axonal neuropathy: MRS findings.

    PubMed

    Alkan, Alpay; Kutlu, Ramazan; Sigirci, Ahmet; Baysal, Tamer; Altinok, Tayfun; Yakinci, Cengiz

    2003-10-01

    Giant axonal neuropathy (GAN) is a rare genetic disease of childhood involving the central and peripheral nervous systems. Axonal loss with several giant axons filled with neurofilaments is the main histopathological feature of peripheral nerve biopsies in this disease. Routine neuroimaging studies reveal diffuse hyperintensities in cerebral and cerebellar white matter. In this case report, the authors present the brain magnetic resonance spectroscopic features (normal N-acetylaspartate/creatine and increased choline/creatine and myoinositol/creatine ratios), which might indicate the absence of neuroaxonal loss and the presence of significant demyelination and glial proliferation in white matter, of an 11-year-old boy diagnosed with GAN. PMID:14569833

  11. Distinguishing black-hole spin-orbit resonances by their gravitational wave signatures. II. Full parameter estimation

    NASA Astrophysics Data System (ADS)

    Trifirò, Daniele; O'Shaughnessy, Richard; Gerosa, Davide; Berti, Emanuele; Kesden, Michael; Littenberg, Tyson; Sperhake, Ulrich

    2016-02-01

    Gravitational waves from coalescing binary black holes encode the evolution of their spins prior to merger. In the post-Newtonian regime and on the precession time scale, this evolution has one of three morphologies, with the spins either librating around one of two fixed points ("resonances") or circulating freely. In this paper we perform full parameter estimation on resonant binaries with fixed masses and spin magnitudes, changing three parameters: a conserved "projected effective spin" ξ and resonant family Δ Φ =0 ,π (which uniquely label the source); the inclination θJ N of the binary's total angular momentum with respect to the line of sight (which determines the strength of precessional effects in the waveform); and the signal amplitude. We demonstrate that resonances can be distinguished for a wide range of binaries, except for highly symmetric configurations where precessional effects are suppressed. Motivated by new insight into double-spin evolution, we introduce new variables to characterize precessing black hole binaries which naturally reflects the time scale separation of the system and therefore better encode the dynamical information carried by gravitational waves.

  12. Newly Discovered Planets Orbiting HD 5319, HD 11506, HD 75784 and HD 10442 from the N2K Consortium

    NASA Astrophysics Data System (ADS)

    Giguere, Matthew J.; Fischer, Debra A.; Payne, Matthew J.; Brewer, John M.; Johnson, John Asher; Howard, Andrew W.; Isaacson, Howard T.

    2015-01-01

    Initially designed to discover short-period planets, the N2K campaign has since evolved to discover new worlds at large separations from their host stars. Detecting such worlds will help determine the giant planet occurrence at semi-major axes beyond the ice line, where gas giants are thought to mostly form. Here we report four newly discovered gas giant planets (with minimum masses ranging from 0.4 to 2.1 M Jup) orbiting stars monitored as part of the Next 2000 target stars (N2K) Doppler Survey program. Two of these planets orbit stars already known to host planets: HD 5319 and HD 11506. The remaining discoveries reside in previously unknown planetary systems: HD 10442 and HD 75784. The refined orbital period of the inner planet orbiting HD 5319 is 641 days. The newly discovered outer planet orbits in 886 days. The large masses combined with the proximity to a 4:3 mean motion resonance make this system a challenge to explain with current formation and migration theories. HD 11506 has one confirmed planet, and here we confirm a second. The outer planet has an orbital period of 1627.5 days, and the newly discovered inner planet orbits in 223.6 days. A planet has also been discovered orbiting HD 75784 with an orbital period of 341.7 days. There is evidence for a longer period signal; however, several more years of observations are needed to put tight constraints on the Keplerian parameters for the outer planet. Lastly, an additional planet has been detected orbiting HD 10442 with a period of 1043 days. Based on observations obtained at the W. M. Keck Observatory, which is operated by the University of California and the California Institute of Technology. Keck time has been granted by NOAO and NASA.

  13. NEWLY DISCOVERED PLANETS ORBITING HD 5319, HD 11506, HD 75784 AND HD 10442 FROM THE N2K CONSORTIUM

    SciTech Connect

    Giguere, Matthew J.; Fischer, Debra A.; Brewer, John M.; Payne, Matthew J.; Johnson, John Asher; Howard, Andrew W.; Isaacson, Howard T.

    2015-01-20

    Initially designed to discover short-period planets, the N2K campaign has since evolved to discover new worlds at large separations from their host stars. Detecting such worlds will help determine the giant planet occurrence at semi-major axes beyond the ice line, where gas giants are thought to mostly form. Here we report four newly discovered gas giant planets (with minimum masses ranging from 0.4 to 2.1 M {sub Jup}) orbiting stars monitored as part of the Next 2000 target stars (N2K) Doppler Survey program. Two of these planets orbit stars already known to host planets: HD 5319 and HD 11506. The remaining discoveries reside in previously unknown planetary systems: HD 10442 and HD 75784. The refined orbital period of the inner planet orbiting HD 5319 is 641 days. The newly discovered outer planet orbits in 886 days. The large masses combined with the proximity to a 4:3 mean motion resonance make this system a challenge to explain with current formation and migration theories. HD 11506 has one confirmed planet, and here we confirm a second. The outer planet has an orbital period of 1627.5 days, and the newly discovered inner planet orbits in 223.6 days. A planet has also been discovered orbiting HD 75784 with an orbital period of 341.7 days. There is evidence for a longer period signal; however, several more years of observations are needed to put tight constraints on the Keplerian parameters for the outer planet. Lastly, an additional planet has been detected orbiting HD 10442 with a period of 1043 days.

  14. Spectral signatures of the ionospheric Alfvén resonator to be observed by low-Earth orbit satellite

    NASA Astrophysics Data System (ADS)

    Surkov, V. V.; Pilipenko, V. A.

    2016-03-01

    Interference of an incident and reflected Alfvén pulses propagating inside the ionospheric Alfvén resonator (IAR) is studied on the basis of a simple one-dimensional model. Particular emphasis has been placed on the analysis of spectral features of ultralow frequency (˜1-15 Hz) electric perturbations recently observed by Communications/Navigation Outage Forecasting System satellite. This "fingerprint" multiband spectral structure was observed when satellite descended in the terminator vicinity. Among factors affecting spectral structure the satellite position and distance from the IAR boundaries are most significant. It is concluded that the observed spectrograms exhibit modulation with "period" depending on propagation delay time of reflected Alfvén pulses in such a way that this effect can mask a spectral resonance structure resulted from excitation of IAR eigenmodes. The proposed interference effect is capable to produce a spectral pattern resembling a fingerprint which is compatible with the satellite observations.

  15. Perturbations of non-resonant satellite orbits due to a rotating earth. [tesseral harmonics and the Von Ziepel method

    NASA Technical Reports Server (NTRS)

    Mueller, A.

    1978-01-01

    The dominant perturbations of the motion of a satellite near the earth are due to atmospheric drag and the non-symmetrical gravitational field. Atmospheric drag perturbation continually pulls the satellite in and out of the different long period resonant frequencies. The result is that the resonances never become apparent and may be neglected. The tesseral harmonics have no true secular perturbation but the periodicities in the mean motion induce a secular perturbation in the mean anomaly. This secular perturbation may be determined by simply using the average mean motion instead of the osculating mean motion. The Von Ziepel method is used to determine tesseral perturbations. The solution is found first in the singular DS phi elements and then rewritten in the PS phi elements to remove singularities. The notation used in the development is described in the appendix.

  16. Resonant soft x-ray scattering investigation of orbital and magnetic ordering in La{sub 0.5}Sr{sub 1.5}MnO{sub 4}

    SciTech Connect

    Wilkins, S.B.; Stojic, N.; Binggeli, N.; Beale, T.A.W.; Hatton, P.D.; Castleton, C.W.M.; Prabhakaran, D.; Boothroyd, A.T.; Altarelli, M.

    2005-06-15

    We report resonant x-ray scattering data of the orbital and magnetic ordering at low temperatures at the Mn L{sub 2,3} edges in La{sub 0.5}Sr{sub 1.5}MnO{sub 4}. The orderings display complex energy features close to the Mn absorption edges. Systematic modeling with atomic multiplet crystal field calculations was used to extract meaningful information regarding the interplay of spin, orbital, and Jahn-Teller order. These calculations provide a good general agreement with the observed energy dependence of the scattered intensity for a dominant orbital ordering of the d{sub x{sup 2}}{sub -z{sup 2}}/d{sub y{sup 2}}{sub -z{sup 2}} type. In addition, the origins of various spectral features are identified. The temperature dependence of the orbital and magnetic ordering was measured and suggests a strong interplay between the magnetic and orbital order parameters.

  17. RCNP E398 {sup 16}O,{sup 12}C(p,p’) experiment: Measurement of the γ-ray emission probability from giant resonances in relation to {sup 16}O,{sup 12}C(ν,ν’) reactions

    SciTech Connect

    Ou, I.; Yamada, Y.; Mori, T.; Yano, T.; Sakuda, M.; Tamii, A.; Suzuki, T.; Yosoi, M.; Aoi, N.; Ideguchi, E.; Hashimoto, T.; Miki, K.; Ito, T.; Iwamoto, C.; Yamamoto, T.; Akimune, H.

    2015-05-15

    We propose to measure the γ-ray emission probability from excited states above 5 MeV including giant resonance of {sup 16}O and {sup 12}C as a function of excitation energy in 1-MeV step. Here, we measure both the excitation energy (E{sub x}=5-30MeV) at the forward scattering angles (0°-3°) of the {sup 16}O, {sup 12}C (p, p’) reaction using Grand-Raiden Spectrometer and the energy of γ-rays (E{sub γ}) using an array of NaI(Tl) counters. The purpose of the experiment is to provide the basic and important information not only for the γ-ray production from primary neutral-current neutrino-oxygen (-carbon) interactions but also for that from the secondary hadronic (neutron-oxygen and -carbon) interactions.

  18. Giant Axonal Neuropathy

    MedlinePlus

    ... Diversity Find People About NINDS NINDS Giant Axonal Neuropathy Information Page Table of Contents (click to jump ... done? Clinical Trials Organizations What is Giant Axonal Neuropathy? Giant axonal neuropathy (GAN) is a rare inherited ...

  19. Structure of expanded porphyrins: electron-nuclear multiple resonance and molecular orbital studies of texaphyrin anion radicals in solution

    NASA Astrophysics Data System (ADS)

    Endeward, B.; Regev, A.; Plato, M.; Levanon, H.; Sessler, J. L.; Möbius, K.

    1994-08-01

    Liquid solution ENDOR and TRIPLE resonance experiments have been performed on texaphyrin radical anions generated by sodium reduction in tetrahydrofuran. Six proton and two nitrogen hyperfine couplings could be determined, including their signs. The results were compared with theoretical isotropic hyperfine couplings. They were calculated for energy-minimized texaphyrin structures, including the sodium metallo-derivative, by state-of-the-art SCF-MO methods (RHF-INDO/SP). This comparison suggests that in the course of the alkali metal reduction of texaphyrin the acidic hydrogen in the macrocycle is replaced by sodium.

  20. Preliminary models of the resonant trans-Neptunian populations from the Outer Solar System Origins Survey

    NASA Astrophysics Data System (ADS)

    Volk, Kathryn; Gladman, Brett; Murray-Clay, Ruth; Lawler, Samantha

    2014-11-01

    The dynamical history of the solar system’s giant planets left its signature in the orbital distribution trans-Neptunian objects (TNOs). In particular, the population of resonant TNOs is crucial to understanding Neptune’s orbital evolution in the early solar system. Resonant TNOs are subject to complicated detection biases, so estimating the intrinsic resonant TNO population from observations requires a well-characterized survey. We present preliminary models and population estimates for the resonant TNOs based on detections from the first 25% of the Outer Solar System Origins Survey (OSSOS, see abstract by Gladman et al). We discuss small improvements that need to be made to the Canada-France Ecliptic Plane Survey models for the 3:2, 2:1, and 5:2 resonances (Gladman et al 2012) in order to match the full data set. We will discuss some puzzles in the orbital distributions inside of these resonances which appear to be increasingly statistically significant. We demonstrate improvements in the 3:2 resonance mode that will be possible with future OSSOS observations which are expected to increase the total number of well-characterized 3:2 objects by a factor of a few over the Canada-France Ecliptic Plane Survey. The improved resonance models from OSSOS will be a useful lever arm on the processes by which the resonances were filled.

  1. Urey Prize Lecture: Orbital Dynamics of Extrasolar Planets, Large and Small

    NASA Astrophysics Data System (ADS)

    Ford, Eric B.

    2012-10-01

    For centuries, planet formation theories were fine tuned to explain the details of solar system. Since 1999, the Doppler technique has discovered dozens of multiple planet systems. The diversity of architectures of systems with giant planets challenged previous theories and led to insights into planet formation, orbital migration and the excitation of orbital eccentricities and inclinations. Recently, NASA's Kepler mission has identified over 300 systems with multiple transiting planet candidates, including many potentially rocky planets. Precise measurements of the orbital period and phase constrain the significance of mutual gravitational interactions and potential orbital resonances. For systems that are tightly-packed or near an orbital resonance, measurements of transit timing variations provide a new means for confirming transiting planets and detecting non-transiting planets in multiple planet systems, even around faint target stars. Over the course of the extended mission, Kepler is poised to measure the gravitational effects of mutual planetary perturbations for 200 planets, providing precise (but complex) constraints on planetary masses, densities and orbits. I will survey the systems with multiple transiting planet candidates identified by Kepler and discuss early efforts to translate these observations into new constraints on the formation and orbital evolution of planetary systems with low-mass planets.

  2. Origin of the obliquities of the giant planets in mutual interactions in the early Solar System.

    PubMed

    Brunini, Adrián

    2006-04-27

    The origin of the spin-axis orientations (obliquities) of the giant planets is a fundamental issue because if the obliquities resulted from tangential collisions with primordial Earth-sized protoplanets, then they are related to the masses of the largest planetesimals out of which the planets form. A problem with this mechanism, however, is that the orbital planes of regular satellites would probably be uncorrelated with the obliquities, contrary to observations. Alternatively, they could have come from an external twist that affected the orientation of the Solar System plane; but in this model, the outer planets must have formed too rapidly, before the event that produced the twist. Moreover, the model cannot be quantitatively tested. Here I show that the present obliquities of the giant planets were probably achieved when Jupiter and Saturn crossed the 1:2 orbital resonance during a specific migration process: different migration scenarios cannot account for the large observed obliquities. The existence of the regular satellites of the giant planets does not represent a problem in this model because, although they formed soon after the planetary formation, they can follow the slow evolution of the equatorial plane it produces. PMID:16641989

  3. Resonant Removal of Exomoons during Planetary Migration

    NASA Astrophysics Data System (ADS)

    Spalding, Christopher; Batygin, Konstantin; Adams, Fred C.

    2016-01-01

    Jupiter and Saturn play host to an impressive array of satellites, making it reasonable to suspect that similar systems of moons might exist around giant extrasolar planets. Furthermore, a significant population of such planets is known to reside at distances of several Astronomical Units (AU), leading to speculation that some moons thereof might support liquid water on their surfaces. However, giant planets are thought to undergo inward migration within their natal protoplanetary disks, suggesting that gas giants currently occupying their host star’s habitable zone formed farther out. Here we show that when a moon-hosting planet undergoes inward migration, dynamical interactions may naturally destroy the moon through capture into a so-called evection resonance. Within this resonance, the lunar orbit’s eccentricity grows until the moon eventually collides with the planet. Our work suggests that moons orbiting within about ∼10 planetary radii are susceptible to this mechanism, with the exact number dependent on the planetary mass, oblateness, and physical size. Whether moons survive or not is critically related to where the planet began its inward migration, as well as the character of interlunar perturbations. For example, a Jupiter-like planet currently residing at 1 AU could lose moons if it formed beyond ∼5 AU. Cumulatively, we suggest that an observational census of exomoons could potentially inform us on the extent of inward planetary migration, for which no reliable observational proxy currently exists.

  4. Giant facial lymphangioma.

    PubMed

    Sanger, Claire; Wong, Lindsey; Wood, Jeyhan; David, Lisa R; Argenta, Louis C

    2011-07-01

    Lymphatic malformation (LM) is a benign cystic entity resulting from aberrant lymphatic drainage. Often evident at birth, most LMs have declared themselves by 2 years of age. They can be concerning when they occur near vital structures such as the airway or orbit. The natural history varies considerable from spontaneous gradual regression to long-term growth and debilitation. Depending on the location, structures involved, and clinical course of the LM, therapeutic options include observation, intralesional sclerosis, laser therapy, and surgical excision. The literature provides guidelines for treatment options that must be carefully applied to the facial region. We present a newborn infant who presented to our institution with giant facial lymphangioma who underwent a combination of sclerosis, laser ablation, and surgery with reconstruction. PMID:21772195

  5. Could Jupiter or Saturn Have Ejected a Fifth Giant Planet?

    NASA Astrophysics Data System (ADS)

    Cloutier, Ryan; Tamayo, Daniel; Valencia, Diana

    2015-11-01

    Models of the dynamical evolution of the early solar system that follow the dispersal of the gaseous protoplanetary disk have been widely successful in reconstructing the current orbital configuration of the giant planets. Statistically, some of the most successful dynamical evolution simulations have initially included a hypothetical fifth giant planet, of ice giant (IG) mass, which gets ejected by a gas giant during the early solar system’s proposed instability phase. We investigate the likelihood of an IG ejection (IGE) event by either Jupiter or Saturn through constraints imposed by the current orbits of their wide-separation regular satellites Callisto and Iapetus, respectively. We show that planetary encounters that are sufficient to eject an IG often provide excessive perturbations to the orbits of Callisto and Iapetus, making it difficult to reconcile a planet ejection event with the current orbit of either satellite. Quantitatively, we compute the likelihood of reconciling a regular Jovian satellite orbit with the current orbit of Callisto following an IGE by Jupiter of ∼42%, and conclude that such a large likelihood supports the hypothesis of a fifth giant planet’s existence. A similar calculation for Iapetus reveals that it is much more difficult for Saturn to have ejected an IG and reconciled a Kronian satellite orbit with that of Iapetus (likelihood ∼1%), although uncertainties regarding the formation of Iapetus, with its unusual orbit, complicates the interpretation of this result.

  6. Orbits and Interiors of Planets

    NASA Astrophysics Data System (ADS)

    Batygin, Konstantin

    2012-05-01

    The focus of this thesis is a collection of problems of timely interest in orbital dynamics and interior structure of planetary bodies. The first three chapters are dedicated to understanding the interior structure of close-in, gaseous extrasolar planets (hot Jupiters). In order to resolve a long-standing problem of anomalously large hot Jupiter radii, we proposed a novel magnetohydrodynamic mechanism responsible for inflation. The mechanism relies on the electro-magnetic interactions between fast atmospheric flows and the planetary magnetic field in a thermally ionized atmosphere, to induce electrical currents that flow throughout the planet. The resulting Ohmic dissipation acts to maintain the interior entropies, and by extension the radii of hot Jupiters at an enhanced level. Using self-consistent calculations of thermal evolution of hot Jupiters under Ohmic dissipation, we demonstrated a clear tendency towards inflated radii for effective temperatures that give rise to significant ionization of K and Na in the atmosphere, a trend fully consistent with the observational data. Furthermore, we found that in absence of massive cores, low-mass hot Jupiters can over-flow their Roche-lobes and evaporate on Gyr time-scales, possibly leaving behind small rocky cores. Chapters four through six focus on the improvement and implications of a model for orbital evolution of the solar system, driven by dynamical instability (termed the "Nice" model). Hydrodynamical studies of the orbital evolution of planets embedded in protoplanetary disks suggest that giant planets have a tendency to assemble into multi-resonant configurations. Following this argument, we used analytical methods as well as self-consistent numerical N-body simulations to identify fully-resonant primordial states of the outer solar system, whose dynamical evolutions give rise to orbital architectures that resemble the current solar system. We found a total of only eight such initial conditions, providing

  7. CHAOTIC DIFFUSION OF RESONANT KUIPER BELT OBJECTS

    SciTech Connect

    Tiscareno, Matthew S.; Malhotra, Renu

    2009-09-15

    We carried out extensive numerical orbit integrations to probe the long-term chaotic dynamics of the two strongest mean-motion resonances of Neptune in the Kuiper Belt, the 3:2 (Plutinos) and 2:1 (Twotinos). Our primary results include a computation of the relative volumes of phase space characterized by large- and small-resonance libration amplitudes, and maps of resonance stability measured by mean chaotic diffusion rate. We find that Neptune's 2:1 resonance has weaker overall long-term stability than the 3:2-only {approx}15% of Twotinos are projected to survive for 4 Gyr, compared to {approx}27% of Plutinos, based on an extrapolation from our 1-Gyr integrations. We find that Pluto has only a modest effect, causing a {approx}4% decrease in the Plutino population that survives to 4 Gyr. Given current observational estimates, and assuming an initial distribution of particles proportional to the local phase-space volume in the resonance, we conclude that the primordial populations of Plutinos and Twotinos formerly made up more than half the population of the classical and resonant Kuiper Belt. We also conclude that Twotinos were originally nearly as numerous as Plutinos; this is consistent with predictions from early models of smooth giant planet migration and resonance sweeping of the Kuiper Belt and provides a useful constraint for more detailed models.

  8. Giant Magnons Meet Giant Gravitons

    SciTech Connect

    Hofman, Diego M.

    2008-07-28

    We study the worldsheet reflection matrix of a string attached to a D-brane in AdS{sub 5}xS{sup 5}. The D-brane corresponds to a maximal giant graviton that wraps an S{sup 3} inside S{sup 5}. In the gauge theory, the open string is described by a spin chain with boundaries. We focus on open strings with a large SO(6) charge and define an asymptotic boundary reflection matrix. Using the symmetries of the problem, we review the computation of the boundary reflection matrix, up to a phase. We also discuss weak and strong coupling computations where we obtain the overall phase factor and test our exact results.

  9. Planetesimals embedded in a gaseous disc vs mean-motion resonances

    NASA Astrophysics Data System (ADS)

    Chrenko, Ondrej; Broz, Miroslav

    2015-11-01

    We study orbital evolution of km-sized planetesimals in a gaseous disc with one or more embedded giant protoplanets. Especially, we focus on the regions intersected by the inner mean-motion resonances with the innermost ("Jovian") protoplanet, e.g. 2:1, 5:2, 8:3, 3:1. The planetesimals orbiting in these regions are subject to combined effects of aerodynamic and resonant perturbations. We aim to numerically investigate two possible outcomes of this interplay. First, stable resonant islands can exist (as in Chrenko et al. 2015) and may slow down or capture planetesimals as they spiral sunward. In such a case, the resonances might serve as natural barriers for the flux of planetesimals and locally accelerate the accumulation of the solid material.Second, the resonances can overcome the damping effects of the gas and pump the eccentricities of the crossing planetesimals (Marzari & Weidenschilling 2002). This process might generate eccentric orbits which lead to increased relative velocities with respect to the nebular gas and crossing of non-resonant (circular) orbits. The environment of the gaseous disc is simulated with the FARGO code (Masset 2000), which is a 2D Eulerian solver of the fluid equations with fast azimuthal advection. We modified the code so it can treat small planetesimals as test particles affected by the respective aerodynamic drag.Acknowledgements: The work of OC and MB has been supported by Charles University in Prague, project GA UK No. 1062214.

  10. Orbital physics in RIXS

    NASA Astrophysics Data System (ADS)

    Wohlfeld, Krzysztof; Marra, Pasquale; Grueninger, Markus; Schmitt, Thorsten; van den Brink, Jeroen

    2013-03-01

    In contrast to magnetism, phenomena associated with the orbital degrees of freedom in transition metal oxides had always been considered to be very difficult to observe. However, recently resonant inelastic x-ray scattering (RIXS) has established itself as a perfect probe of the orbital excitations and orbital order in transition metal oxides. Here we give a brief overview of these recent theoretical and experimental advances which have inter alia led to the observation of the separation of the spin and orbital degree of freedom of an electron.

  11. Giant Planets in Open Clusters

    NASA Astrophysics Data System (ADS)

    Quinn, S. N.; White, R. J.; Latham, D. W.

    2015-10-01

    Two decades after the discovery of 51 Peg b, more than 200 hot Jupiters have now been confirmed, but the details of their inward migration remain uncertain. While it is widely accepted that short period giant planets could not have formed in situ, several different mechanisms (e.g., Type II migration, planet-planet scattering, Kozai-Lidov cycles) may contribute to shrinking planetary orbits, and the relative importance of each is not well-constrained. Migration through the gas disk is expected to preserve circular, coplanar orbits and must occur quickly (within ˜ 10 Myr), whereas multi-body processes should initially excite eccentricities and inclinations and may take hundreds of millions of years. Subsequent evolution of the system (e.g., orbital circularization and inclination damping via tidal interaction with the host star) may obscure these differences, so observing hot Jupiters soon after migration occurs can constrain the importance of each mechanism. Fortunately, the well-characterized stars in young and adolescent open clusters (with known ages and compositions) provide natural laboratories for such studies, and recent surveys have begun to take advantage of this opportunity. We present a review of the discoveries in this emerging realm of exoplanet science, discuss the constraints they provide for giant planet formation and migration, and reflect on the future direction of the field.

  12. Mass loss in red giants and supergiants

    NASA Technical Reports Server (NTRS)

    Sanner, F.

    1975-01-01

    The circumstellar envelopes surrounding late-type giants and supergiants were studied using high resolution, photoelectric scans of strong optical resonance lines. A method for extracting the circumstellar from the stellar components of the lines allowed a quantitative determination of the physical conditions in the envelopes and the rates of mass loss at various positions in the red giant region of the HR diagram. The observed strengthening of the circumstellar spectrum with increasing luminosity and later spectral type is probably caused by an increase in the mass of the envelopes. The mass loss rate for individual stars is proportional to the visual luminosity; high rates for the supergiants suggest that mass loss is important in their evolution. The bulk of the mass return to the interstellar medium in the red giant region comes from the normal giants, at a rate comparable to that of planetary nebulae.

  13. Unusual sclerosing orbital pseudotumor infiltrating orbits and maxillofacial regions.

    PubMed

    Toprak, Huseyin; Aralaşmak, Ayşe; Yılmaz, Temel Fatih; Ozdemir, Huseyin

    2014-01-01

    Idiopathic orbital pseudotumor (IOP) is a benign inflammatory condition of the orbit without identifiable local or systemic causes. Bilateral massive orbital involvement and extraorbital extension of the IOP is very rare. We present an unusual case of IOP with bilateral massive orbital infiltration extending into maxillofacial regions and discuss its distinctive magnetic resonance imaging (MRI) features that help to exclude other entities during differential diagnoses. PMID:24991481

  14. Unusual Sclerosing Orbital Pseudotumor Infiltrating Orbits and Maxillofacial Regions

    PubMed Central

    Toprak, Huseyin; Aralaşmak, Ayşe; Yılmaz, Temel Fatih; Ozdemir, Huseyin

    2014-01-01

    Idiopathic orbital pseudotumor (IOP) is a benign inflammatory condition of the orbit without identifiable local or systemic causes. Bilateral massive orbital involvement and extraorbital extension of the IOP is very rare. We present an unusual case of IOP with bilateral massive orbital infiltration extending into maxillofacial regions and discuss its distinctive magnetic resonance imaging (MRI) features that help to exclude other entities during differential diagnoses. PMID:24991481

  15. Kepler-223: A Resonant Chain of Four Transiting, Sub-Neptune Planets

    NASA Astrophysics Data System (ADS)

    Mills, Sean; Fabrycky, Daniel C.; Migaszewski, Cezary; Ford, Eric B.; Petigura, Erik; Isaacson, Howard T.

    2016-05-01

    Surveys have revealed an abundance of multi-planet systems containing super-Earths and Neptunes in few-day to few-month orbits. Orbital periods of pairs of planets in the same system occasionally lie near, but generally not exactly on, ratios of small integers (resonances), allowing for the detection of the planets perturbing each other. There is debate whether in situ assembly or significant inward migration is the dominant mechanism of their formation. Simulations suggest migration creates tightly-packed, resonant systems, often in chains of resonance. Of the hundreds of multi-planet systems of sub-Neptunes, there is weak statistical enhancement near resonances, but no individual system has been identified that requires migration. Here we describe dynamical modeling of the system Kepler-223, which has a series of resonances among its four planets. We observe transit timing variations (TTVs), model them as resonant angle librations, and compute long-term stability, combining these analyses to constrain dynamical parameters and planetary masses. The detailed architecture of Kepler-223 is too finely tuned for formation by scattering, whereas numerical simulations demonstrate its properties are natural outcomes of the migration hypothesis. Similar systems could be destabilized by many mechanisms contributing to the observed period distribution. Planetesimal interactions in particular are thought to be responsible for establishing thecurrent orbits of the four giant planets in our own Solar System by disrupting a theoretical initial resonant chain like that actually observed in Kepler-223.

  16. THE RESONANT TRANS-NEPTUNIAN POPULATIONS

    SciTech Connect

    Gladman, B.; Lawler, S. M.; Van Laerhoven, C.; Petit, J.-M.; Rousselot, P.; Kavelaars, J.; Jones, R. L.; Parker, J. Wm.; Bieryla, A.; Nicholson, P.; Ashby, M. L. N.

    2012-07-15

    The trans-Neptunian objects (TNOs) trapped in mean-motion resonances with Neptune were likely emplaced there during planet migration late in the giant-planet formation process. We perform detailed modeling of the resonant objects detected in the Canada-France Ecliptic Plane Survey (CFEPS) in order to provide population estimates and, for some resonances, constrain the complex internal orbital element distribution. Detection biases play a critical role because phase relationships with Neptune make object discovery more likely at certain longitudes. This paper discusses the 3:2, 5:2, 2:1, 3:1, 5:1, 4:3, 5:3, 7:3, 5:4, and 7:4 mean-motion resonances, all of which had CFEPS detections, along with our upper limit on 1:1 Neptune Trojans (which is consistent with their small population estimated elsewhere). For the plutinos (TNOs in the 3:2 resonance) we refine the orbital element distribution given by Kavelaars et al. in 2009 and show that steep H-magnitude distributions (N(H){proportional_to}10{sup {alpha}H}, with {alpha} = 0.8-0.9) are favored in the range H{sub g} = 8-9, and confirm that this resonance does not share the inclination distribution of the classical Kuiper Belt. We give the first population estimate for the 5:2 resonance and find that, to within the uncertainties, the population is equal to that of the 3:2 ({approx_equal}13,000 TNOs with H{sub g} < 9.16), whereas the 2:1 population is smaller by a factor of 3-4 compared to the other two resonances. We also measure significant populations inhabiting the 4:3, 5:3, 7:3, 5:4, 7:4, 3:1, and 5:1 resonances, with H{sub g} < 9.16 (D > 100 km) populations in the thousands. We compare our intrinsic population and orbital element distributions with several published models of resonant-TNO production; the most striking discrepancy is that resonances beyond the 2:1 are in reality more heavily populated than in published models.

  17. Recurrent renal giant leiomyosarcoma

    PubMed Central

    Öziş, Salih Erpulat; Gülpınar, Kamil; Şahlı, Zafer; Konak, Baha Burak; Keskin, Mete; Özdemir, Süleyman; Ataoğlu, Ömür

    2016-01-01

    Primary renal leiomyosarcomas are rare, aggressive tumors. They constitute 1–2% of adult malignant renal tumors. Although leiomyosarcomas are the most common histological type (50–60%) of renal sarcomas, information on renal leiomyosarcoma is limited. Local or systemic recurrences are common. The radiological appearance of renal leiomyosarcomas is not specific, therefore renal leiomyosarcoma cannot be distinguished from renal cell carcinoma by imaging methods in all patients. A 74-year-old female patient presented to our clinic complaining of a palpable mass on the right side of her abdomen in November 2012. The abdominal magnetic resonance imaging revealed a mass, 25 × 24 × 23 cm in size. Her past medical history revealed that she has undergone right radical nephrectomy in 2007, due to a 11 × 12 × 13 cm renal mass that was then reported as renal cell carcinoma on abdominal magnetic resonance imaging, but the pathological diagnosis was low-grade renal leiomyosarcoma. The most recent follow-up of the patient was in 2011, with no signs of local recurrence or distant metastases within this four-year period. The patient underwent laparotomy on November 2012, and a 35 cm retroperitoneal mass was excised. The pathological examination of the mass was reported as high-grade leiomyosarcoma. The formation of this giant retroperitoneal mass in 1 year can be explained by the transformation of the lesion’s pathology from low-grade to a high-grade tumor.

  18. Strong orbital expansion of Saturn’s inner ice-rich moons through ring torques and mutual resonances during their accretion from a massive ring

    NASA Astrophysics Data System (ADS)

    Salmon, Julien; Canup, Robin M.

    2015-11-01

    Saturn has a diversity of moons with possibly diverse origins. Titan likely formed in Saturn’s sub-nebula (e.g., Canup & Ward 2006). The small moons interior to Mimas are likely recent aggregates of ring’s material spreading through the Roche limit (Charnoz et al. 2010). The origin of the mid-size moons, Mimas through Rhea, is debated. Charnoz et al. (2011) considered a massive ice-rock ring and strong tidal dissipation in Saturn (Q ~ 103), and found that moons out to Rhea could be spawned from such a ring. However such a small value for Q for Saturn is debated. In addition, capture into mutual Mean Motion Resonances (MMR) and resulting eccentricity growth (not included in the Charnoz et al. (2011) model) could lead to orbital destabilization as the moons tidally expand over such large distances (Peale & Canup 2015).Here we consider weak planetary tides (Q ≥ 104) and investigate whether Mimas, Enceladus and Tethys could have been spawned from a massive ice ring (Canup 2010). In this scenario, the rock in these moons would be delivered by material from outside the rings, e.g. by heliocentric impactors during the LHB (Canup 2013). We have expanded a numerical model developed to study the Moon’s accretion (Salmon and Canup 2012, 2014), which couples an analytic Roche-interior disk model to the N-body code SyMBA (Duncan et al. 1998) for satellites, so that we can directly track their accretion and mutual interactions (including MMRs), as well as their tidal interaction with the planet. We consider an initially large Saturn (Fortney et al. 2007) and its progressive contraction, which impacts the strength of tides and the location of the corotation resonance. We perform simulations with and without Dione and Rhea, and study the influence of tidal dissipation into the moons.We find that recoil of the moons due to ring torques, together with capture of moons into MMRs, can produce a distribution similar to that observed. If tidal dissipation in the moons was weak

  19. Giant Cell Arteritis

    MedlinePlus

    Giant cell arteritis is a disorder that causes inflammation of your arteries, usually in the scalp, neck, and arms. ... arteries, which keeps blood from flowing well. Giant cell arteritis often occurs with another disorder called polymyalgia ...

  20. Preliminary models of the resonant transneptunian populations from the Outer Solar System Origins Survey

    NASA Astrophysics Data System (ADS)

    Volk, K.; Gladman, B.; Murray-Clay, R.; Lawler, S.

    2014-07-01

    The dynamical history of our solar system's giant planets left its signature in the orbital distribution of small bodies in the transneptunian region. The outer solar system's dynamical history is particularly important in the origin and distribution of the transneptunian objects (TNOs) in Neptune's mean-motion resonances. Understanding the current population of resonant TNOs is crucial to understanding Neptune's orbital evolution in the early solar system. However, resonant TNOs are subject to complicated detection biases due to the resonant nature of their orbits. In addition to the usual biases due to distance and ecliptic latitude, resonant objects only come to perihelion at a specific range of longitude relative to Neptune (see Gladman et al. 2012, Lawler et al. 2013). Estimating the intrinsic resonant TNO population from observations requires a well-characterized survey so these biases can be accounted for. The Outer Solar System Origins Survey (OSSOS), which began observations in February 2013, will provide a sample of well-characterized resonant TNOs which can be used to model the intrinsic resonant populations. We present preliminary models of the resonant TNOs based on detections from the first two blocks of OSSOS observations. We show that the Canada-France Ecliptic Plane Survey models of the 3:2, 2:1, and 5:2 resonances (Gladman et al. 2012) are consistent with the OSSOS observations so far. For reference, the figure shows the 3:2 resonance model from Gladman et al. 2012 with the locations of the first two OSSOS blocks. We will discuss improvements in the 3:2 resonance model that will be possible with future OSSOS observations which are expected to increase the total number of well-characterized 3:2 objects by a factor of a few over the Canada-France Ecliptic Plane Survey.

  1. Giant impacts on giant planets

    NASA Astrophysics Data System (ADS)

    de Pater, Imke

    2012-10-01

    The 2009 impact on Jupiter caught the world by surprise and cast doubt on impactor flux estimates for the outer solar system. Enhanced amateur planetary imaging techniques yield both high spatial resolution {enabling the 2009 impact debris field detection} and rapid frame rates {enabling the 2010 impact flash detections and lightcurve measurements}.We propose a Target of Opportunity program to image future impacts on Jupiter and Saturn. To remove the possibility of impact cloud non-detections, the program will be triggered only if an existing impact debris field is seen, an object on a collision course with Jupiter or Saturn is discovered, or an impact light curve is measured with an estimated total energy large enough to generate an impact cloud in a giant planet atmosphere.HST provides the only way to image these events in the ultraviolet, providing information on aerosol altitudes and on smaller particles that are less visible to ground-based infrared observations. High-resolution imaging with proper timing {not achievable from the ground} is required to measure precisely both the velocity fields of impact sites and the optical spectrum of impact debris. HST observations of past impacts on Jupiter have also served both as cornerstones of science investigations at other wavelengths and as vehicles for effective public outreach.Large outer solar system impacts are governed by the same physics as in the terrestrial events that dominate the impact threat to humans. Studying the behavior of impactors of various sizes and compositions, as they enter the atmosphere at varying angles and speeds, will better quantify terrestrial impact hazards.

  2. Giant impacts on giant planets

    NASA Astrophysics Data System (ADS)

    de Pater, Imke

    2014-10-01

    The 2009 impact and recent superbolides on Jupiter caught the world by surprise and cast doubt on impactor flux estimates for the outer solar system. Enhanced amateur planetary imaging techniques yield both high spatial resolution (enabling the 2009 impact debris field detection) and rapid frame rates (enabling the 2010/2012 impact flash detections and lightcurve measurements).We propose a ToO program to image future impacts on Jupiter and Saturn. To remove the possibility of impact cloud non-detections, the program will be triggered only if an existing impact debris field is seen, an object on a collision course with Jupiter or Saturn is discovered, or an impact light curve is measured with an estimated total energy large enough to generate an impact cloud in a giant planet atmosphere (10^20 J).HST provides the only way to image these events in the ultraviolet, providing information on aerosol altitudes and on smaller particles that are less visible to ground-based infrared observations. High-resolution imaging with proper timing (not achievable from the ground) is required to measure precisely both the velocity fields of impact sites and the optical spectrum of impact debris. HST observations of past impacts on Jupiter have also served both as cornerstones of science investigations at other wavelengths and as vehicles for effective public outreach.Large outer solar system impacts are governed by the same physics as in the terrestrial events that dominate the impact threat to humans. Studying the behavior of impactors of various sizes and compositions, as they enter the atmosphere at varying angles and speeds, will better quantify terrestrial impact hazards.

  3. Giant impacts on giant planets

    NASA Astrophysics Data System (ADS)

    de Pater, Imke

    2013-10-01

    The 2009 impact and recent superbolides on Jupiter caught the world by surprise and cast doubt on impactor flux estimates for the outer solar system. Enhanced amateur planetary imaging techniques yield both high spatial resolution {enabling the 2009 impact debris field detection} and rapid frame rates {enabling the 2010/2012 impact flash detections and lightcurve measurements}.We propose a ToO program to image future impacts on Jupiter and Saturn. To remove the possibility of impact cloud non-detections, the program will be triggered only if an existing impact debris field is seen, an object on a collision course with Jupiter or Saturn is discovered, or an impact light curve is measured with an estimated total energy large enough to generate an impact cloud in a giant planet atmosphere {10^20 J}.HST provides the only way to image these events in the ultraviolet, providing information on aerosol altitudes and on smaller particles that are less visible to ground-based infrared observations. High-resolution imaging with proper timing {not achievable from the ground} is required to measure precisely both the velocity fields of impact sites and the optical spectrum of impact debris. HST observations of past impacts on Jupiter have also served both as cornerstones of science investigations at other wavelengths and as vehicles for effective public outreach.Large outer solar system impacts are governed by the same physics as in the terrestrial events that dominate the impact threat to humans. Studying the behavior of impactors of various sizes and compositions, as they enter the atmosphere at varying angles and speeds, will better quantify terrestrial impact hazards.

  4. STATISTICAL STUDY OF THE EARLY SOLAR SYSTEM'S INSTABILITY WITH FOUR, FIVE, AND SIX GIANT PLANETS

    SciTech Connect

    Nesvorny, David; Morbidelli, Alessandro

    2012-10-01

    Several properties of the solar system, including the wide radial spacing and orbital eccentricities of giant planets, can be explained if the early solar system evolved through a dynamical instability followed by migration of planets in the planetesimal disk. Here we report the results of a statistical study, in which we performed nearly 10{sup 4} numerical simulations of planetary instability starting from hundreds of different initial conditions. We found that the dynamical evolution is typically too violent, if Jupiter and Saturn start in the 3:2 resonance, leading to ejection of at least one ice giant from the solar system. Planet ejection can be avoided if the mass of the transplanetary disk of planetesimals was large (M{sub disk} {approx}> 50 M{sub Earth}), but we found that a massive disk would lead to excessive dynamical damping (e.g., final e{sub 55} {approx}< 0.01 compared to present e{sub 55} = 0.044, where e{sub 55} is the amplitude of the fifth eccentric mode in the Jupiter's orbit), and to smooth migration that violates constraints from the survival of the terrestrial planets. Better results were obtained when the solar system was assumed to have five giant planets initially, and one ice giant, with mass comparable to that of Uranus and Neptune, was ejected into interstellar space by Jupiter. The best results were obtained when the ejected planet was placed into the external 3:2 or 4:3 resonance with Saturn and M{sub disk} {approx_equal} 20 M{sub Earth}. The range of possible outcomes is rather broad in this case, indicating that the present solar system is neither a typical nor expected result for a given initial state, and occurs, in best cases, with only a {approx_equal}5% probability (as defined by the success criteria described in the main text). The case with six giant planets shows interesting dynamics but does offer significant advantages relative to the five-planet case.

  5. Orbital and magnetic ordering in Pr1-xCaxMnO3 and Nd1-xSrxMnO3 manganites near half doping studied by resonant soft x-ray powder diffraction

    NASA Astrophysics Data System (ADS)

    Staub, U.; García-Fernández, M.; Bodenthin, Y.; Scagnoli, V.; de Souza, R. A.; Garganourakis, M.; Pomjakushina, E.; Conder, K.

    2009-06-01

    Here we present resonant soft x-ray diffraction data in the vicinity of the MnL2,3 edges on R1-xTxMnO3 manganites ( R=Pr , Nd and T=Ca , Sr) close to half doping. For Pr0.6Ca0.4MnO3 (PCMO), the energy dependence of the superimposed orbital and magnetic reflections are studied using various incident x-ray polarizations. For Nd0.5Sr0.5MnO3 (NSMO), the energy dependence of the orbital ordering reflection is found to be very similar to that found in other manganites systems. These two results are compared to those presented in the literature on single-crystal samples. Whereas our results are in good agreement with the spectral shape of a superposition of magnetic and orbital signals in PCMO, the magnetic signals are only moderately larger than the orbital signals. The results on NSMO do not agree with previously presented data on single crystals and cast doubt on the proposed occurrence of a double-stripe orbital order.

  6. Rotation of Giant Stars

    NASA Astrophysics Data System (ADS)

    Kissin, Yevgeni; Thompson, Christopher

    2015-07-01

    The internal rotation of post-main sequence stars is investigated, in response to the convective pumping of angular momentum toward the stellar core, combined with a tight magnetic coupling between core and envelope. The spin evolution is calculated using model stars of initial mass 1, 1.5, and 5 {M}⊙ , taking into account mass loss on the giant branches. We also include the deposition of orbital angular momentum from a sub-stellar companion, as influenced by tidal drag along with the excitation of orbital eccentricity by a fluctuating gravitational quadrupole moment. A range of angular velocity profiles {{Ω }}(r) is considered in the envelope, extending from solid rotation to constant specific angular momentum. We focus on the backreaction of the Coriolis force, and the threshold for dynamo action in the inner envelope. Quantitative agreement with measurements of core rotation in subgiants and post-He core flash stars by Kepler is obtained with a two-layer angular velocity profile: uniform specific angular momentum where the Coriolis parameter {Co}\\equiv {{Ω }}{τ }{con}≲ 1 (here {τ }{con} is the convective time), and {{Ω }}(r)\\propto {r}-1 where {Co}≳ 1. The inner profile is interpreted in terms of a balance between the Coriolis force and angular pressure gradients driven by radially extended convective plumes. Inward angular momentum pumping reduces the surface rotation of subgiants, and the need for a rejuvenated magnetic wind torque. The co-evolution of internal magnetic fields and rotation is considered in Kissin & Thompson, along with the breaking of the rotational coupling between core and envelope due to heavy mass loss.

  7. Warm Disks from Giant Impacts

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2015-10-01

    In the process of searching for exoplanetary systems, weve discovered tens of debris disks close around distant stars that are especially bright in infrared wavelengths. New research suggests that we might be looking at the late stages of terrestrial planet formation in these systems.Forming Terrestrial PlanetsAccording to the widely-accepted formation model for our solar-system, protoplanets the size of Mars formed within a protoplanetary disk around our Sun. Eventually, the depletion of the gas in the disk led the orbits of these protoplanets to become chaotically unstable. Finally, in the giant impact stage, many of the protoplanets collided with each other ultimately leading to the formation of the terrestrial planets and their moons as we know them today.If giant impact stages occur in exoplanetary systems, too leading to the formation of terrestrial exoplanets how would we detect this process? According to a study led by Hidenori Genda of the Tokyo Institute of Technology, we might be already be witnessing this stage in observations of warm debris disks around other stars. To test this, Genda and collaborators model giant impact stages and determine what we would expect to see from a system undergoing this violent evolution.Modeling CollisionsSnapshots of a giant impact in one of the authors simulations. The collision causes roughly 0.05 Earth masses of protoplanetary material to be ejected from the system. Click for a closer look! [Genda et al. 2015]The collaborators run a series of simulations evolving protoplanetary bodies in a solar system. The simulations begin 10 Myr into the lifetime of the solar system, i.e., after the gas from the protoplanetary disk has had time to be cleared and the protoplanetary orbits begin to destabilize. The simulations end when the protoplanets are done smashing into each other and have again settled into stable orbits, typically after ~100 Myr.The authors find that, over an average giant impact stage, the total amount of

  8. Management of giant liver hemangiomas: an update.

    PubMed

    Hoekstra, Lisette T; Bieze, Matthanja; Erdogan, Deha; Roelofs, Joris J T H; Beuers, Ulrich H W; van Gulik, Thomas M

    2013-03-01

    Liver hemangiomas are the most common benign liver tumors and are usually incidental findings. Liver hemangiomas are readily demonstrated by abdominal ultrasonography, computed tomography or magnetic resonance imaging. Giant liver hemangiomas are defined by a diameter larger than 5 cm. In patients with a giant liver hemangioma, observation is justified in the absence of symptoms. Surgical resection is indicated in patients with abdominal (mechanical) complaints or complications, or when diagnosis remains inconclusive. Enucleation is the preferred surgical method, according to existing literature and our own experience. Spontaneous or traumatic rupture of a giant hepatic hemangioma is rare, however, the mortality rate is high (36-39%). An uncommon complication of a giant hemangioma is disseminated intravascular coagulation (Kasabach-Merritt syndrome); intervention is then required. Herein, the authors provide a literature update of the current evidence concerning the management of giant hepatic hemangiomas. In addition, the authors assessed treatment strategies and outcomes in a series of patients with giant liver hemangiomas managed in our department. PMID:23445235

  9. The Spectroscopic orbits of HD 23052 and HD 90512

    NASA Astrophysics Data System (ADS)

    Scarfe, C. D.; Griffin, R. F.

    2012-10-01

    We present radial-velocity observations from DAO and Cambridge, from which we derive orbital elements. HD 23052 is a G-type main-sequence object which has been regarded as a solar analogue, in an orbit of period nearly three years. HD 90512 is a G-type giant in a nearly circular orbit with a period just over 100 days.

  10. Unveiling the evolution and formation of icy giants

    NASA Astrophysics Data System (ADS)

    Dirkx, D.; Bocanegra, T.; Bracken, C.; Costa, M.; Gerth, I.; Konstantinidis, K.; Labrianidis, C.; Laneuville, M.; Luntzer, A.; MacArthur, J.; Maier, A.; Morschhauser, A.; Nordheim, T.; Sallantin, R.; Tlustos, R.

    2013-09-01

    The planet Uranus is one of two ice giants in the solar system, both of which have only been visited only once by the Voyager 2 spacecraft. Ice giants represent a fundamental class of planet, and in fact, many known exoplanets fall in this category. Therefore, a dedicated mission to an ice giant is crucial to deepen our understanding of the formation, evolution and current characteristics of such planetary and exoplanetary systems. Here we present the results of a detailed study of a mission to investigate the Uranus system as an archetype for ice giants. Our detailed trade-off study has resulted in a mission configuration consisting of an orbiter with a deep atmospheric probe and an extensive orbital tour of the main moons of the Uranus system.

  11. Did the Kozai Resonance Help Form Pluto's Small Moons?

    NASA Astrophysics Data System (ADS)

    Cuk, Matija; (Luke) Dones, Henry C.; Nesvorny, David; Walsh, Kevin J.

    2016-05-01

    The origin of the small moons of Pluto is currently poorly understood. They most likely originated from debris ejected from Pluto and Charon during their formation in the giant impact. However, the moons' large separation from Pluto and massive past tidal evolution of Charon make it very hard to emplace collisional fragments on circular orbits in the 40-60 Pluto radii zone where the four small moons are found. Here we propose that the Pluto system has a parallel in the triple Trans-Neptunian Object (TNO) 1999 TC36. Both systems have large obliquities, and have additional components outside the inner binary that probably formed in a giant impact and has likely gone through a rapid tidal evolution immediately following formation. Our hypothesis is that loosely bound ejecta from giant impacts can experience strong perturbations from the Sun (the ``Kozai resonance") as long as major axes of their elongated orbits are perpendicular to the binary's heliocentric orbit. This process could decouple the debris from the inner boundary long enough for the inner binary to evolve tidally and prevent further Kozai oscillations through its quadrupole moment. If the debris is dominated by one large fragment, a triple can form (as in the case of 1999 TC36), while a large population of fragments would experience collisions and make a disk surrounding the inner binary (as in the case of Pluto). At the meeting we will present numerical simulations of this process using numerical integrator COMPLEX which includes both tides and solar perturbations, and can integrate dynamics of satellites on crossing orbits.

  12. Orbits and Interiors of Planets

    NASA Astrophysics Data System (ADS)

    Batygin, Konstantin

    2012-05-01

    The focus of this thesis is a collection of problems of timely interest in orbital dynamics and interior structure of planetary bodies. The first three chapters are dedicated to understanding the interior structure of close-in, gaseous extrasolar planets (hot Jupiters). In order to resolve a long-standing problem of anomalously large hot Jupiter radii, we proposed a novel magnetohydrodynamic mechanism responsible for inflation. The mechanism relies on the electro-magnetic interactions between fast atmospheric flows and the planetary magnetic field in a thermally ionized atmosphere, to induce electrical currents that flow throughout the planet. The resulting Ohmic dissipation acts to maintain the interior entropies, and by extension the radii of hot Jupiters at an enhanced level. Using self-consistent calculations of thermal evolution of hot Jupiters under Ohmic dissipation, we demonstrated a clear tendency towards inflated radii for effective temperatures that give rise to significant ionization of K and Na in the atmosphere, a trend fully consistent with the observational data. Furthermore, we found that in absence of massive cores, low-mass hot Jupiters can over-flow their Roche-lobes and evaporate on Gyr time-scales, possibly leaving behind small rocky cores. Chapters four through six focus on the improvement and implications of a model for orbital evolution of the solar system, driven by dynamical instability (termed the "Nice" model). Hydrodynamical studies of the orbital evolution of planets embedded in protoplanetary disks suggest that giant planets have a tendency to assemble into multi-resonant configurations. Following this argument, we used analytical methods as well as self-consistent numerical N-body simulations to identify fully-resonant primordial states of the outer solar system, whose dynamical evolutions give rise to orbital architectures that resemble the current solar system. We found a total of only eight such initial conditions, providing

  13. Coupling between Orbital and Lattice Degrees of Freedom in Y1-xCaxTiO3 (0 < x ≤ 0.75): A Resonant X-ray Scattering Study

    NASA Astrophysics Data System (ADS)

    Tsubota, Masami; Iga, Fumitoshi; Uchihira, Kazuyuki; Nakano, Toshihiro; Kura, Soichiro; Takabatake, Toshiro; Kodama, Soukichi; Nakao, Hironori; Murakami, Youichi

    2005-12-01

    We have studied the orbitally ordered states in Y1-xCaxTiO3 (0 < x ≤ 0.75) by resonant X-ray scattering (RXS) near the Ti K-edge (E ˜ 5 keV) and by powder X-ray diffraction measurements. The RXS intensities at the 1s \\to 4 p transition energy (main-edge) gradually decrease with increasing x and remain finite even in the metallic phase for x > 0.4. In contrast, the intensities at the 1s \\to 3d transition energy (pre-edge) decrease rapidly with increasing x up to 0.15 and disappear at x ˜ 0.4. The x dependences of the Jahn-Teller distortion is consistent with those of the RXS intensities at pre-edge. Namely, the RXS intensity at the pre-edge energy reflects the orbital ordered state. From our results, we conclude that the magnetic order in Y1-xCaxTiO3 becomes unstable at x ˜ 0.15 when the orbital order is weakened, and the metallic phase appears in x > 0.4 when the order of orbitals melts.

  14. Orbital Properties of the Arecibo Micrometeoroids at Earth Interception

    NASA Astrophysics Data System (ADS)

    Janches, D.; Meisel, D. D.; Mathews, J. D.

    2001-04-01

    Using the Arecibo Observatory (AO) 430-MHz Radar we have developed a Doppler technique to measure very precise micrometeor instantaneous velocities directly from the meteor head echo. In addition, a large number of the observed meteoroids show deceleration. With the velocity, the deceleration, and the assumptions of a spherical shape and a mean micrometeoroid mass density, we have obtained estimates of in-atmosphere particle sizes. The size estimate, the MSIS model atmosphere, and the measured deceleration are used to obtain the meteor extra-atmospheric speeds, assuming these particles undergo little mass-loss prior to and during the time we detect them (Janches et al. 2000b, Icarus145, 53-63). Orbital elements at 1 AU are presented and discussed. These results have not been corrected for perturbation effects such as radiation pressure, Poynting-Robertson drag, attraction by the giant planets, and photoelectric charging effects. So far, over 7700 detections obtained during November 1997 and 3500 during the November 1998 observation campaigns have been analyzed. The observing periods included the Leonids meteor shower, but none of the orbits are recently derived from it. Out of these detections, we present details of over 1500 orbits with eccentricities less than unity. These orbits show (a) a depletion of postperihelion particles with small perihelion distance, suggesting the possibility of collisional and thermal destruction, and (b) an enhancement of particles with perihelia in the zone between Mercury and Venus. Also discussed are 40 β-meteoroids (with radii less than 0.5 μm) dynamically related to the elliptical orbit population with q<0.7 AU. We interpret the latter results on the basis of Poynting-Robertson drag and the electromagnetic resonant effects proposed by G. E. Morfill and E. Grün (1979, Planet. Space Sci.27, 1269-1282). Comparison with previous data sets indicates that most of the AO micrometeoroid orbits are well randomized and that association

  15. From planetesimals to terrestrial planets: N-body simulations including the effects of nebular gas and giant planets

    NASA Astrophysics Data System (ADS)

    Morishima, Ryuji; Stadel, Joachim; Moore, Ben

    2010-06-01

    We present results from a suite of N-body simulations that follow the formation and accretion history of the terrestrial planets using a new parallel treecode that we have developed. We initially place 2000 equal size planetesimals between 0.5 and 4.0 AU and the collisional growth is followed until the completion of planetary accretion (>100 Myr). A total of 64 simulations were carried out to explore sensitivity to the key parameters and initial conditions. All the important effect of gas in laminar disks are taken into account: the aerodynamic gas drag, the disk-planet interaction including Type I migration, and the global disk potential which causes inward migration of secular resonances as the gas dissipates. We vary the initial total mass and spatial distribution of the planetesimals, the time scale of dissipation of nebular gas (which dissipates uniformly in space and exponentially in time), and orbits of Jupiter and Saturn. We end up with 1-5 planets in the terrestrial region. In order to maintain sufficient mass in this region in the presence of Type I migration, the time scale of gas dissipation needs to be 1-2 Myr. The final configurations and collisional histories strongly depend on the orbital eccentricity of Jupiter. If today's eccentricity of Jupiter is used, then most of bodies in the asteroidal region are swept up within the terrestrial region owing to the inward migration of the secular resonance, and giant impacts between protoplanets occur most commonly around 10 Myr. If the orbital eccentricity of Jupiter is close to zero, as suggested in the Nice model, the effect of the secular resonance is negligible and a large amount of mass stays for a long period of time in the asteroidal region. With a circular orbit for Jupiter, giant impacts usually occur around 100 Myr, consistent with the accretion time scale indicated from isotope records. However, we inevitably have an Earth size planet at around 2 AU in this case. It is very difficult to obtain

  16. Earth Co-orbital Objects

    NASA Astrophysics Data System (ADS)

    Wiegert, P.; Connors, M.; Chodas, P.; Veillet, C.; Mikkola, S.; Innanen, K.

    2002-12-01

    The recent discovery of asteroid 2002 AA29 by the LINEAR survey and the realization of its co-orbital relationship with Earth lead us to consider the characteristics of Earth Co-orbital Objects (ECOs) in general. An object with semimajor axis between 0.99 and 1.01 AU is in 1:1 resonance with the Earth. To be co-orbital in the sense of moving along the Earth's orbit, an object must further have its other orbital parameters similar to those of the Earth. Clarification is needed as to what range of orbital parameters can be regarded as similar enough to permit classification as an ECO. ECOs would be expected to librate on tadpole or horseshoe orbits, be relatively easy to access with spacecraft, and to sometimes exhibit quasisatellite behavior. 2002 AA29 is on a horseshoe orbit and was discovered in a general asteroid survey while near Earth at one end of the horseshoe orbit. Searches for Earth Trojan asteroids, which would be members of the ECO class on tadpole orbits near a triangular Lagrange Point, have not yet been successful. While 2002 AA29 has an orbit even less eccentric than Earth's, it has an inclination of about 10 degrees. 2000 PH5 and 2001 GO2 are on horseshoe orbits and interact gravitationally with Earth to 'bounce' when they approach the Earth from either side. With eccentricities of .23 and .17 respectively, they do not have decidedly Earth-like orbits despite inclinations less that 5 degrees. When in quasi-satellite mode, a body exhibits a looping motion relative to Earth in some ways resembling a satellite orbit. Several resonant bodies including 3753 Cruithne exhibit this behavior at times, but ECOs remain close to Earth while doing it. We suggest that directed searches be used to discover ECOs and characterize this class of objects. Orbital simulations suggest the best target spaces, which are only partially covered by present general searches.

  17. Orbit to orbit transportation

    NASA Technical Reports Server (NTRS)

    Bergeron, R. P.

    1980-01-01

    Orbital transfer vehicle propulsion options for SPS include both chemical (COTV) and electrical (EOTV) options. The proposed EOTV construction method is similar to that of the SPS and, by the addition of a transmitting antenna, may serve as a demonstration or precursor satellite option. The results of the studies led to the selection of a single stage COTV for crew and priority cargo transfer. An EOTV concept is favored for cargo transfer because of the more favorable orbital burden factor over chemical systems. The gallium arsenide solar array is favored over the silicon array because of its self annealing characteristics of radiation damage encountered during multiple transitions through the Van Allen radiation belt. Transportation system operations are depicted. A heavy lift launch vehicle (HLLV) delivers cargo and propellants to LEO, which are transferred to a dedicated EOTV by means of an intraorbit transfer vehicle (IOTV) for subsequent transfer to GEO. The space shuttle is used for crew transfer from Earth to LEO. At the LEO base, the crew module is removed from the shuttle cargo bay and mated to a COTV for transfer to GEO. Upon arrival at GEO, the SPS construction cargo is transferred from the EOTV to the SPS construction base by IOTV. Crew consumables and resupply propellants are transported to GEO by the EOTV. Transportation requirements are dominated by the vast quantity of materials to be transported to LEO and GEO.

  18. Imaging in orbital trauma

    PubMed Central

    Lin, Ken Y.; Ngai, Philip; Echegoyen, Julio C.; Tao, Jeremiah P.

    2012-01-01

    Orbital trauma is one of the most common reasons for ophthalmology specialty consultation in the emergency department setting. We survey the literature from 1990 to present to describe the role of computed tomography (CT), magnetic resonance imaging (MRI) and their associated angiography in some of the most commonly encountered orbital trauma conditions. CT orbit can often detect certain types of foreign bodies, lens dislocation, ruptured globe, choroidal or retinal detachments, or cavernous sinus thrombosis and thus complement a bedside ophthalmic exam that can sometimes be limited in the setting of trauma. CT remains the workhorse for acute orbital trauma owing to its rapidity and ability to delineate bony abnormalities; however MRI remains an important modality in special circumstances such as soft tissue assessment or with organic foreign bodies. PMID:23961028

  19. Peripheral giant cell granuloma.

    PubMed

    Adlakha, V K; Chandna, P; Rehani, U; Rana, V; Malik, P

    2010-01-01

    Peripheral giant cell granuloma is a benign reactive lesion of gingiva. It manifests as a firm, soft, bright nodule or as a sessile or pedunculate mass. This article reports the management of peripheral giant cell granuloma in a 12-year-old boy by surgical excision. PMID:21273719

  20. Giant Cell Tumor of the Peroneus Brevis Tendon Sheath

    PubMed Central

    Ch, Li; TH, Lui

    2015-01-01

    Introduction: Giant cell tumor of the tendon sheath is most commonly found in the flexor aspect of hand and wrist and is rare in the foot and ankle. Case report: A 49-year-old lady noticed a right lateral foot mass for 10 years. Magnetic resonance imaging suggested that the mass is originated from the peroneal tendons. The mass was excised and intra-operative findings showed that the tumor came from the peroneus brevis tendon sheath. Histological study confirmed the diagnosis of giant cell tumor. Conclusion: Giant cell tumor, although rare, should be one of the differential diagnoses of tendon sheath tumor of the foot and ankle. PMID:27299104

  1. Hilda Asteroid Colors: Insight into Giant Planet Migration?

    NASA Astrophysics Data System (ADS)

    Sharkey, Benjamin; Ryan, Erin L.; Woodward, Charles E.; Noll, Keith S.

    2016-01-01

    The Hilda asteroids are a unique population of small bodies that are locked in a 3:2 mean motion resonance with Jupiter. Unlike other resonances in the asteroid belt, the 3:2 is a stable resonance at 3.95 AU. Objects at this resonance have stable orbits for at least 2 GYr and, more likely, for the age of the Solar System. In an instantaneous top down view of the solar system, the Hildas approximately trace a triangle with over-densities of asteroids near the L3, L4 and L5 Jovian Lagrange points. This configuration is cited as evidence that Jupiter migrated inwards by ~0.4 AU. Stable Hilda orbits have mean eccentricities of 0.16 with typical perihelia of 3.15 AU. These latter properties, in terms of observability and accessibility to spacecraft, are a major advantage that distinguishes the Hildas from other populations of potential scientific interest such as the Jovian Trojans. The Outer Main Belt (OMB) also has many objects that may have originated in the outer protoplanetary disk (OPD). However, the OMB appears to be more mixed with objects from elsewhere in the Main Belt and enjoys only a small advantage in terms of brightness for a given diameter and albedo. The intrinsic collisional probability for objects in the Hilda population is also a factor of 3 to 5 less than the collisional probabilities for Trojan and OMB populations. Thus, the Hildas likely represent a significant population of objects unaltered due to collisional processing. Here we discuss findings of our ongoing NASA Planetary Astronomy program to obtain Sloan optical (g' r' i' z') colors of Hilda-group asteroids. The loci of these colors are compared to the Kuiper Belt populations to test post-formation migration effects of the giant planets in our solar system on the small body population. In part, this work was conducted as part of a University of Minnesota Undergraduate Research Scholarship, and is supported by NASA PAST Award NNX13AJ11G.

  2. Deep Imaging of Giant Planets

    NASA Astrophysics Data System (ADS)

    Chauvin, G.

    2010-10-01

    With the development of high contrast imaging instruments and techniques, vast efforts have been devoted during the past decade to detect and characterize lighter, cooler and closer companions to nearby stars, and ultimately image new planetary systems. Complementary to other observing techniques (radial velocity, transit, micro-lensing, pulsar-timing and astrometry), this approach has opened a new astrophysical window to study the physical properties and the formation and evolution mechanisms of giant planets at orbits larger than a few AUs. In this review, I will briefly present the main motivations to use deep imaging to search for exoplanets and review the constant progress achieved thanks to improved performances of advanced instrumentation and data analysis techniques. I will describe the main classes of stars identified and observed so far to increase the chances of detection. I will also detail the classical strategy adopted to identify false alarms and characterize true companions. I will review the current status of the different deep imaging surveys as well as the main results that recently led to the discovery of giant planets probably formed like the ones of our solar system. Finally, I will rise the questions and uncertainties related to the formation mechanisms, the physical properties and the frequency of these planetary mass companions to conclude with the exciting and attractive perspectives offered with the future generation of deep imaging instruments.

  3. A compact system of small planets around a former red-giant star.

    PubMed

    Charpinet, S; Fontaine, G; Brassard, P; Green, E M; Van Grootel, V; Randall, S K; Silvotti, R; Baran, A S; Ostensen, R H; Kawaler, S D; Telting, J H

    2011-12-22

    Planets that orbit their parent star at less than about one astronomical unit (1 AU is the Earth-Sun distance) are expected to be engulfed when the star becomes a red giant. Previous observations have revealed the existence of post-red-giant host stars with giant planets orbiting as close as 0.116 AU or with brown dwarf companions in tight orbits, showing that these bodies can survive engulfment. What has remained unclear is whether planets can be dragged deeper into the red-giant envelope without being disrupted and whether the evolution of the parent star itself could be affected. Here we report the presence of two nearly Earth-sized bodies orbiting the post-red-giant, hot B subdwarf star KIC 05807616 at distances of 0.0060 and 0.0076 AU, with orbital periods of 5.7625 and 8.2293 hours, respectively. These bodies probably survived deep immersion in the former red-giant envelope. They may be the dense cores of evaporated giant planets that were transported closer to the star during the engulfment and triggered the mass loss necessary for the formation of the hot B subdwarf, which might also explain how some stars of this type did not form in binary systems. PMID:22193103

  4. Harmonically excited orbital variations

    SciTech Connect

    Morgan, T.

    1985-08-06

    Rephrasing the equations of motion for orbital maneuvers in terms of Lagrangian generalized coordinates instead of Newtonian rectangular cartesian coordinates can make certain harmonic terms in the orbital angular momentum vector more readily apparent. In this formulation the equations of motion adopt the form of a damped harmonic oscillator when torques are applied to the orbit in a variationally prescribed manner. The frequencies of the oscillator equation are in some ways unexpected but can nonetheless be exploited through resonant forcing functions to achieve large secular variations in the orbital elements. Two cases are discussed using a circular orbit as the control case: (1) large changes in orbital inclination achieved by harmonic excitation rather than one impulsive velocity change, and (2) periodic and secular changes to the longitude of the ascending node using both stable and unstable excitation strategies. The implications of these equations are also discussed for both artificial satellites and natural satellites. For the former, two utilitarian orbits are suggested, each exploiting a form of harmonic excitation. 5 refs.

  5. Giant optical nonlinearity of plasmonic nanostructures

    SciTech Connect

    Melentiev, P N; Afanasev, A E; Balykin, V I

    2014-06-30

    The experimental studies of giant optical nonlinearity of single metal nanostructures are briefly reviewed. A new hybrid nanostructure – split-hole resonator (SHR) – is investigated. This structure is characterised by a record-high efficiency of third-harmonic generation and multiphoton luminescence (its nonlinearity exceeds that of a single nanohole by five orders of magnitude) and an unprecedently high sensitivity to light polarisation (extinction coefficient 4 × 10{sup 4}). (extreme light fields and their applications)

  6. Orbital pseudotumor

    MedlinePlus

    ... Names Idiopathic orbital inflammatory syndrome (IOIS) Images Skull anatomy References Goodlick TA, Kay MD, Glaser JS, Tse DT, Chang WJ. Orbital disease and neuro-ophthalmology. In: Tasman W, Jaeger EA, eds. Duane’s ...

  7. Kepler's Orbit

    NASA Video Gallery

    Kepler does not orbit the Earth, rather it orbits the Sun in concert with the Earth, slowly drifting away from Earth. Every 61 Earth years, Kepler and Earth will pass by each other. Throughout the ...

  8. Orbital cellulitis

    MedlinePlus

    ... Haemophilus influenzae B) vaccine. The bacteria Staphylococcus aureus , Streptococcus pneumoniae , and beta-hemolytic streptococci may also cause orbital cellulitis. Orbital cellulitis infections in children may get worse very quickly and can lead ...

  9. Trojan resonant dynamics, stability, and chaotic diffusion, for parameters relevant to exoplanetary systems

    NASA Astrophysics Data System (ADS)

    Páez, Rocío Isabel; Efthymiopoulos, Christos

    2015-02-01

    The possibility that giant extrasolar planets could have small Trojan co-orbital companions has been examined in the literature from both viewpoints of the origin and dynamical stability of such a configuration. Here we aim to investigate the dynamics of hypothetical small Trojan exoplanets in domains of secondary resonances embedded within the tadpole domain of motion. To this end, we consider the limit of a massless Trojan companion of a giant planet. Without other planets, this is a case of the elliptic restricted three body problem (ERTBP). The presence of additional planets (hereafter referred to as the restricted multi-planet problem, RMPP) induces new direct and indirect secular effects on the dynamics of the Trojan body. The paper contains a theoretical and a numerical part. In the theoretical part, we develop a Hamiltonian formalism in action-angle variables, which allows us to treat in a unified way resonant dynamics and secular effects on the Trojan body in both the ERTBP or the RMPP. In both cases, our formalism leads to a decomposition of the Hamiltonian in two parts, . , called the basic model, describes resonant dynamics in the short-period (epicyclic) and synodic (libration) degrees of freedom, while contains only terms depending trigonometrically on slow (secular) angles. is formally identical in the ERTBP and the RMPP, apart from a re-definition of some angular variables. An important physical consequence of this analysis is that the slow chaotic diffusion along resonances proceeds in both the ERTBP and the RMPP by a qualitatively similar dynamical mechanism. We found that this is best approximated by the paradigm of `modulational diffusion'. In the paper's numerical part, we then focus on the ERTBP in order to make a detailed numerical demonstration of the chaotic diffusion process along resonances. Using color stability maps, we first provide a survey of the resonant web for characteristic mass parameter values of the primary, in which the

  10. Neptune Polar Orbiter with Probes

    NASA Technical Reports Server (NTRS)

    Bienstock, Bernard; Atkinson, David; Baines, Kevin; Mahaffy, Paul; Steffes, Paul; Atreya, Sushil; Stern, Alan; Wright, Michael; Willenberg, Harvey; Smith, David; Frampton, Robert; Sichi, Steve; Peltz, Leora; Masciarelli, James; VanCleve, Jeffey

    2005-01-01

    The giant planets of the outer solar system divide into two distinct classes: the gas giants Jupiter and Saturn, which consist mainly of hydrogen and helium; and the ice giants Uranus and Neptune, which are believed to contain significant amounts of the heavier elements oxygen, nitrogen, and carbon and sulfur. Detailed comparisons of the internal structures and compositions of the gas giants with those of the ice giants will yield valuable insights into the processes that formed the solar system and, perhaps, other planetary systems. By 2012, Galileo, Cassini and possibly a Jupiter Orbiter mission with microwave radiometers, Juno, in the New Frontiers program, will have yielded significant information on the chemical and physical properties of Jupiter and Saturn. A Neptune Orbiter with Probes (NOP) mission would deliver the corresponding key data for an ice giant planet. Such a mission would ideally study the deep Neptune atmosphere to pressures approaching and possibly exceeding 1000 bars, as well as the rings, Triton, Nereid, and Neptune s other icy satellites. A potential source of power would be nuclear electric propulsion (NEP). Such an ambitious mission requires that a number of technical issues be investigated, however, including: (1) atmospheric entry probe thermal protection system (TPS) design, (2) probe structural design including seals, windows, penetrations and pressure vessel, (3) digital, RF subsystem, and overall communication link design for long term operation in the very extreme environment of Neptune's deep atmosphere, (4) trajectory design allowing probe release on a trajectory to impact Neptune while allowing the spacecraft to achieve a polar orbit of Neptune, (5) and finally the suite of science instruments enabled by the probe technology to explore the depths of the Neptune atmosphere. Another driving factor in the design of the Orbiter and Probes is the necessity to maintain a fully operational flight system during the lengthy transit time

  11. Is the Grand Tack model compatible with the orbital distribution of main belt asteroids?

    NASA Astrophysics Data System (ADS)

    Deienno, Rogerio; Gomes, Rodney S.; Walsh, Kevin J.; Morbidelli, Alessandro; Nesvorný, David

    2016-07-01

    The Asteroid Belt is characterized by the radial mixing of bodies with different physical properties, a very low mass compared to Minimum Mass Solar Nebula expectations and has an excited orbital distribution, with eccentricities and inclinations covering the entire range of values allowed by the constraints of dynamical stability. Models of the evolution of the Asteroid Belt show that the origin of its structure is strongly linked to the process of terrestrial planet formation. The Grand Tack model presents a possible solution to the conundrum of reconciling the small mass of Mars with the properties of the Asteroid Belt, including the mass depletion, radial mixing and orbital excitation. However, while the inclination distribution produced in the Grand Tack model is in good agreement with the one observed, the eccentricity distribution is skewed towards values larger than those found today. Here, we evaluate the evolution of the orbital properties of the Asteroid Belt from the end of the Grand Tack model (at the end of the gas nebula phase when planets emerge from the dispersing gas disk), throughout the subsequent evolution of the Solar System including an instability of the Giant Planets approximately 400 Myr later. Before the instability, the terrestrial planets were modeled on dynamically cold orbits with Jupiter and Saturn locked in a 3:2 mean motion resonance. The model continues for an additional 4.1 Gyr after the giant planet instability. Our results show that the eccentricity distribution obtained in the Grand Tack model evolves towards one very similar to that currently observed, and the semimajor axis distribution does the same. The inclination distribution remains nearly unchanged with a slight preference for depletion at low inclination; this leads to the conclusion that the inclination distribution at the end of the Grand Tack is a bit over-excited. Also, we constrain the primordial eccentricities of Jupiter and Saturn, which have a major influence

  12. The evolution of a Pluto-like system during the migration of the ice giants

    NASA Astrophysics Data System (ADS)

    Pires, Pryscilla; Giuliatti Winter, Silvia M.; Gomes, Rodney S.

    2015-01-01

    The planetary migration of the Solar System giant planets in the framework of the Nice model (Tsiganis, K., Gomes, R., Morbidelli, A., Levison, H.F. [2005]. Nature 435,459-461; Morbidelli, A., Levison, H.F., Tsiganis, K., Gomes, R. [2005]. Nature 435, 462-465; Gomes, R., Levison, H.F., Tsiganis, K., Morbidelli, A. [2005]. Nature 435, 466-469) creates a dynamical mechanism which can be used to explain the distribution of objects currently observed in the Kuiper belt (e.g., Levison, H.F., Morbidelli, A., Vanlaerhoven, C., Gomes, R., Tsiganis, K. [2008]. Icarus 196, 258-273). Through this mechanism the planetesimals within the disk, heliocentric distance ranging from beyond Neptune's orbit to approximately 34 AU, are delivered to the belt after a temporary eccentric phase of Uranus and Neptune's orbits. We reproduced the mechanism proposed by Levison et al. to implant bodies into the Kuiper belt. The capture of Pluto into the external 3:2 mean motion resonance with Neptune is associated with this gravitational scattering model. We verified the existence of several close encounters between the ice giants and the planetesimals during their outward radial migration, then we believe that the analysis of the dynamical history of the plutonian satellites during this kind of migration is important, and would provide some constrains about their place of formation - within the primordial planetesimal disk or in situ. We performed N-body simulations and recorded the trajectories of the planetesimals during close approaches with Uranus and Neptune. Close encounters with Neptune are the most common, reaching approximately 1200 in total. A Pluto similarly sized body assumed the hyperbolic trajectories of the former primordial planetesimal with respect to those giant planets. We assumed the current mutual orbital configuration and sizes for Pluto's satellites, then we found that the rate of destruction of systems similar to that of Pluto with closest approaches to Uranus or Neptune

  13. (1) Majorana fermions in pinned vortices; (2) Manipulating and probing Majorana fermions using superconducting circuits; and (3) Controlling a nanowire spin-orbit qubit via electric-dipole spin resonance

    NASA Astrophysics Data System (ADS)

    Nori, Franco

    2014-03-01

    We study a heterostructure which consists of a topological insulator and a superconductor with a hole. This system supports a robust Majorana fermion state bound to the vortex core. We study the possibility of using scanning tunneling spectroscopy (i) to detect the Majorana fermion in this setup and (ii) to study excited states bound to the vortex core. The Majorana fermion manifests itself as an H-dependent zero-bias anomaly of the tunneling conductance. The excited states spectrum differs from the spectrum of a typical Abrikosov vortex, providing additional indirect confirmation of the Majorana state observation. We also study how to manipulate and probe Majorana fermions using super-conducting circuits. In we consider a semiconductor nanowire quantum dot with strong spin-orbit coupling (SOC), which can be used to achieve a spin-orbit qubit. In contrast to a spin qubit, the spin-orbit qubit can respond to an external ac electric field, i.e., electric-dipole spin resonance. We develop a theory that can apply in the strong SOC regime. We find that there is an optimal SOC strength ηopt = √ 2/2, where the Rabi frequency induced by the ac electric field becomes maximal. Also, we show that both the level spacing and the Rabi frequency of the spin-orbit qubit have periodic responses to the direction of the external static magnetic field. These responses can be used to determine the SOC in the nanowire. FN is partly supported by the RIKEN CEMS, iTHES Project, MURI Center for Dynamic Magneto-Optics, JSPS-RFBR Contract No. 12-02-92100, Grant-in-Aid for Scientific Research (S), MEXT Kakenhi on Quantum Cybernetics, and the JSPS via its FIRST program.

  14. Discrete resonances

    NASA Astrophysics Data System (ADS)

    Vivaldi, Franco

    2015-12-01

    The concept of resonance has been instrumental to the study of Hamiltonian systems with divided phase space. One can also define such systems over discrete spaces, which have a finite or countable number of points, but in this new setting the notion of resonance must be re-considered from scratch. I review some recent developments in the area of arithmetic dynamics which outline some salient features of linear and nonlinear stable (elliptic) orbits over a discrete space, and also underline the difficulties that emerge in their analysis.

  15. Discrete resonances

    NASA Astrophysics Data System (ADS)

    Vivaldi, Franco

    The concept of resonance has been instrumental to the study of Hamiltonian systems with divided phase space. One can also define such systems over discrete spaces, which have a finite or countable number of points, but in this new setting the notion of resonance must be re-considered from scratch. I review some recent developments in the area of arithmetic dynamics which outline some salient features of linear and nonlinear stable (elliptic) orbits over a discrete space, and also underline the difficulties that emerge in their analysis.

  16. Unstable giant gravitons

    SciTech Connect

    Mello Koch, Robert de; Ives, Norman; Smolic, Jelena; Smolic, Milena

    2006-03-15

    We find giant graviton solutions in Frolov's three parameter generalization of the Lunin-Maldacena background. The background we study has {gamma}-tilde{sub 1}=0 and {gamma}-tilde{sub 2}={gamma}-tilde{sub 3}={gamma}-tilde. This class of backgrounds provides a nonsupersymmetric example of the gauge theory/gravity correspondence that can be tested quantitatively, as recently shown by Frolov, Roiban, and Tseytlin. The giant graviton solutions we find have a greater energy than the point gravitons, making them unstable states. Despite this, we find striking quantitative agreement between the gauge theory and gravity descriptions of open strings attached to the giant.

  17. Frozen Orbital Plane Solutions for Satellites in Nearly Circular Orbit

    NASA Astrophysics Data System (ADS)

    Ulivieri, Carlo; Circi, Christian; Ortore, Emiliano; Bunkheila, Federico; Todino, Francesco

    2013-08-01

    This paper deals with the determination of the initial conditions (right ascension of the ascending node and inclination) that minimize the orbital plane variation for nearly circular orbits with a semimajor axis between 3 and 10 Earth radii. An analysis of two-line elements over the last 40 years for mid-, geostationary-, and high-Earth orbits has shown, for initially quasi-circular orbits, low eccentricity variations up to the geostationary altitude. This result makes the application of mathematical models based on satellite circular orbits advantageous for a fast prediction of long-term temporal evolution of the orbital plane. To this purpose, a previous model considering the combined effect due to the Earth's oblateness, moon, and sun (both in circular orbit) has been improved in terms of required computational time and accuracy. The eccentricity of the sun and moon and the equinoctial precession have been taken into account. Resonance phenomena with the lunar plane motion have been found in mid-Earth orbit. Dynamical properties concerning the precession motions of the orbital pole have been investigated, and frozen solutions for geosynchronous and navigation satellites have been proposed. Finally, an accurate model validation has also been carried out by comparing the obtained results with two-line elements of abandoned geostationary-Earth orbit and mid-Earth orbit satellites.

  18. Constraining Planetary Migration Mechanisms in Systems of Giant Planets

    NASA Astrophysics Data System (ADS)

    Dawson, Rebekah I.; Murray-Clay, Ruth A.; Johnson, John Asher

    2014-01-01

    It was once widely believed that planets formed peacefully in situ in their proto-planetary disks and subsequently remain in place. Instead, growing evidence suggests that many giant planets undergo dynamical rearrangement that results in planets migrating inward in the disk, far from their birthplaces. However, it remains debated whether this migration is caused by smooth planet-disk interactions or violent multi-body interactions. Both classes of model can produce Jupiter-mass planets orbiting within 0.1 AU of their host stars, also known as hot Jupiters. In the latter class of model, another planet or star in the system perturbs the Jupiter onto a highly eccentric orbit, which tidal dissipation subsequently shrinks and circularizes during close passages to the star. We assess the prevalence of smooth vs. violent migration through two studies. First, motivated by the predictions of Socrates et al. (2012), we search for super-eccentric hot Jupiter progenitors by using the ``photoeccentric effect'' to measure the eccentricities of Kepler giant planet candidates from their transit light curves. We find a significant lack of super- eccentric proto-hot Jupiters compared to the number expected, allowing us to place an upper limit on the fraction of hot Jupiters created by stellar binaries. Second, if both planet-disk and multi-body interactions commonly cause giant planet migration, physical properties of the proto-planetary environment may determine which is triggered. We identify three trends in which giant planets orbiting metal rich stars show signatures of planet-planet interactions: (1) gas giants orbiting within 1 AU of metal-rich stars have a range of eccentricities, whereas those orbiting metal- poor stars are restricted to lower eccentricities; (2) metal-rich stars host most eccentric proto-hot Jupiters undergoing tidal circularization; and (3) the pile-up of short-period giant planets, missing in the Kepler sample, is a feature of metal-rich stars and is

  19. Dynamical Evolution of Multi-resonant Systems: The Case of GJ876

    NASA Astrophysics Data System (ADS)

    Batygin, Konstantin; Deck, Katherine M.; Holman, Matthew J.

    2015-05-01

    The GJ 876 system was among the earliest multi-planetary detections outside of the Solar System, and has long been known to harbor a resonant pair of giant planets. Subsequent characterization of the system revealed the presence of an additional Neptune mass object on an external orbit, locked in a three body Laplace mean motion resonance with the previously known planets. While this system is currently the only known extrasolar example of a Laplace resonance, it differs from the Galilean satellites in that the orbital motion of the planets is known to be chaotic. In this work, we present a simple perturbative model that illuminates the origins of stochasticity inherent to this system and derive analytic estimates of the Lyapunov time as well as the chaotic diffusion coefficient. We then address the formation of the multi-resonant structure within a protoplanetary disk and show that modest turbulent forcing in addition to dissipative effects is required to reproduce the observed chaotic configuration. Accordingly, this work places important constraints on the typical formation environments of planetary systems and informs the attributes of representative orbital architectures that arise from extended disk-driven evolution.

  20. THE McDONALD OBSERVATORY PLANET SEARCH: NEW LONG-PERIOD GIANT PLANETS AND TWO INTERACTING JUPITERS IN THE HD 155358 SYSTEM

    SciTech Connect

    Robertson, Paul; Endl, Michael; Cochran, William D.; MacQueen, Phillip J.; Brugamyer, Erik J.; Barnes, Stuart I.; Caldwell, Caroline; Wittenmyer, Robert A.; Horner, J.; Simon, Attila E.

    2012-04-10

    We present high-precision radial velocity (RV) observations of four solar-type (F7-G5) stars-HD 79498, HD 155358, HD 197037, and HD 220773-taken as part of the McDonald Observatory Planet Search Program. For each of these stars, we see evidence of Keplerian motion caused by the presence of one or more gas giant planets in long-period orbits. We derive orbital parameters for each system and note the properties (composition, activity, etc.) of the host stars. While we have previously announced the two-gas-giant HD 155358 system, we now report a shorter period for planet c. This new period is consistent with the planets being trapped in mutual 2:1 mean-motion resonance. We therefore perform an in-depth stability analysis, placing additional constraints on the orbital parameters of the planets. These results demonstrate the excellent long-term RV stability of the spectrometers on both the Harlan J. Smith 2.7 m telescope and the Hobby-Eberly telescope.

  1. Giant Subclavian Artery Aneurysm.

    PubMed

    Counts, Sarah; Zeeshan, Ahmad; Elefteriades, John

    2016-06-01

    We report the case of a 37-year-old construction executive presenting with chest pain, shortness of breath, and dizziness on exertion secondary to a giant left subclavian artery aneurysm and aortic valvular disease. PMID:27231430

  2. The Next Giant Step

    NASA Video Gallery

    Artist Robert McCall painted "The Next Giant Step" in 1979 to commemorate the heroism and courage of spaceflight pioneers. Located in the lobby of Johnson's building 2, the mural depicts America's ...

  3. The Giant Cell.

    ERIC Educational Resources Information Center

    Stockdale, Dennis

    1998-01-01

    Provides directions for the construction of giant plastic cells, including details for building and installing the organelles. Also contains instructions for preparing the ribosomes, nucleolus, nucleus, and mitochondria. (DDR)

  4. MIGRATION OF GAS GIANT PLANETS IN GRAVITATIONALLY UNSTABLE DISKS

    SciTech Connect

    Michael, Scott; Durisen, Richard H.; Boley, Aaron C. E-mail: durisen@astro.indiana.edu

    2011-08-20

    Characterization of migration in gravitationally unstable disks is necessary to understand the fate of protoplanets formed by disk instability. As part of a larger study, we are using a three-dimensional radiative hydrodynamics code to investigate how an embedded gas giant planet interacts with a gas disk that undergoes gravitational instabilities (GIs). This Letter presents results from simulations with a Jupiter-mass planet placed in orbit at 25 AU within a 0.14 M{sub sun} disk. The disk spans 5-40 AU around a 1 M{sub sun} star and is initially marginally unstable. In one simulation, the planet is inserted prior to the eruption of GIs; in another, it is inserted only after the disk has settled into a quasi-steady GI-active state, where heating by GIs roughly balances radiative cooling. When the planet is present from the beginning, its own wake stimulates growth of a particular global mode with which it strongly interacts, and the planet plunges inward 6 AU in about 10{sup 3} years. In both cases with embedded planets, there are times when the planet's radial motion is slow and varies in direction. At other times, when the planet appears to be interacting with strong spiral modes, migration both inward and outward can be relatively rapid, covering several AUs over hundreds of years. Migration in both cases appears to stall near the inner Lindblad resonance of a dominant low-order mode. Planet orbit eccentricities fluctuate rapidly between about 0.02 and 0.1 throughout the GI-active phases of the simulations.

  5. MASSIVE SATELLITES OF CLOSE-IN GAS GIANT EXOPLANETS

    SciTech Connect

    Cassidy, Timothy A.; Johnson, Robert E.; Mendez, Rolando; Arras, Phil; Skrutskie, Michael F. E-mail: rem5d@cms.mail.virginia.ed E-mail: rej@virginia.ed

    2009-10-20

    We study the orbits, tidal heating and mass loss from satellites around close-in gas giant exoplanets. The focus is on large satellites which are potentially observable by their transit signature. We argue that even Earth-size satellites around hot Jupiters can be immune to destruction by orbital decay; detection of such a massive satellite would strongly constrain theories of tidal dissipation in gas giants, in a manner complementary to orbital circularization. The star's gravity induces significant periodic eccentricity in the satellite's orbit. The resulting tidal heating rates, per unit mass, are far in excess of Io's and dominate radioactive heating out to planet orbital periods of months for reasonable satellite tidal Q. Inside planet orbital periods of about a week, tidal heating can completely melt the satellite. Lastly, we compute an upper limit to the satellite mass loss rate due to thermal evaporation from the surface, valid if the satellite's atmosphere is thin and vapor pressure is negligible. Using this upper limit, we find that although rocky satellites around hot Jupiters with orbital periods less than a few days can be significantly evaporated in their lifetimes, detectable satellites suffer negligible mass loss at longer orbital periods.

  6. Orbital stability constraints on the nature of planetary systems

    NASA Technical Reports Server (NTRS)

    Graziani, F.; Black, D. C.

    1981-01-01

    A fully self-consistent, N-body computer code is used to study conditions under which model planetary systems, each consisting of a star and two 'planetary' companions, become orbitally unstable as a result of gravitational interactions between the companions. A formula describing a necessary condition for orbital stability is given. It is found that giant gaseous protoplanets of the type postulated by Cameron (1978) to be precursors of the present-day solar system planets could have stable orbits for at least 10,000 years, the time required for significant core formation in a typical giant gaseous protoplanet.

  7. [Orbital inflammation].

    PubMed

    Mouriaux, F; Coffin-Pichonnet, S; Robert, P-Y; Abad, S; Martin-Silva, N

    2014-12-01

    Orbital inflammation is a generic term encompassing inflammatory pathologies affecting all structures within the orbit : anterior (involvement up to the posterior aspect of the globe), diffuse (involvement of intra- and/or extraconal fat), apical (involvement of the posterior orbit), myositis (involvement of only the extraocular muscles), dacryoadenitis (involvement of the lacrimal gland). We distinguish between specific inflammation and non-specific inflammation, commonly referred to as idiopathic inflammation. Specific orbital inflammation corresponds to a secondary localization of a "generalized" disease (systemic or auto-immune). Idiopathic orbital inflammation corresponds to uniquely orbital inflammation without generalized disease, and thus an unknown etiology. At the top of the differential diagnosis for specific or idiopathic orbital inflammation are malignant tumors, represented most commonly in the adult by lympho-proliferative syndromes and metastases. Treatment of specific orbital inflammation begins with treatment of the underlying disease. For idiopathic orbital inflammation, treatment (most often corticosteroids) is indicated above all in cases of visual loss due to optic neuropathy, in the presence of pain or oculomotor palsy. PMID:25455557

  8. CT & CBCT imaging: assessment of the orbits.

    PubMed

    Hatcher, David C

    2012-11-01

    The orbits can be visualized easily on routine or customized protocols for computed tomography (CT) or cone beam CT (CBCT) scans. Detailed orbital investigations are best performed with 3-dimensional imaging methods. CT scans are preferred for visualizing the osseous orbital anatomy and fissures while magnetic resonance imaging is preferred for evaluating tumors and inflammation. CBCT provides high-resolution anatomic data of the sinonasal spaces, airway, soft tissue surfaces, and bones but does not provide much detail within the soft tissues. This article discusses CBCT imaging of the orbits, osseous anatomy of the orbits, and CBCT investigation of selected orbital pathosis. PMID:22981080

  9. PLANETS AROUND THE K-GIANTS BD+20 274 AND HD 219415

    SciTech Connect

    Gettel, S.; Wolszczan, A.; Niedzielski, A.; Nowak, G.; Adamow, M.; Zielinski, P.; Maciejewski, G. E-mail: alex@astro.psu.edu

    2012-09-01

    We present the discovery of planet-mass companions to two giant stars by the ongoing Penn State-Torun Planet Search conducted with the 9.2 m Hobby-Eberly Telescope. The less massive of these stars, K5-giant BD+20 274, has a 4.2 M{sub J} minimum mass planet orbiting the star at a 578 day period and a more distant, likely stellar-mass companion. The best currently available model of the planet orbiting the K0-giant HD 219415 points to a {approx}> Jupiter-mass companion in a 5.7 year, eccentric orbit around the star, making it the longest period planet yet detected by our survey. This planet has an amplitude of {approx}18 m s{sup -1}, comparable to the median radial velocity 'jitter', typical of giant stars.

  10. The {sup 57}Fe nuclear magnetic resonance shielding in ferrocene revisited. A density-functional study of orbital energies, shielding mechanisms, and the influence of the exchange-correlation functional

    SciTech Connect

    Schreckenbach, G.

    1999-06-01

    The {sup 57}Fe nuclear magnetic resonance (NMR) shielding and chemical shift in ferrocene, Fe(C{sub 5}H{sub 5}){sub 2}, are studied using density functional theory (DFT) and gauge-including atomic orbitals (GIAO). Electronic factors contributing to the chemical shift are discussed in detail. It is shown that the chemical shift is entirely determined by paramagnetic contributions which in turn are dominated by metal based occupied-virtual d{r_arrow}d couplings. In particular, the HOMO-1(a{sub 1}{sup {prime}}) and the HOMO (e{sub 2}{sup {prime}}) couple with the LUMO (e{sub 1}{sup {double_prime}}). It is argued that the {sup 57}Fe nucleus in ferrocene is less shielded than in the reference compound (iron pentacarbonyl) due to a smaller HOMO-LUMO gap, resulting in stronger interactions between occupied and virtual orbitals. The influence of the XC functional on the calculated molecular orbital (MO) energies of frontier orbitals is discussed. Different generalized gradient approximations (GGA) give similar results whereas hybrid functionals that incorporate part of the Hartree{endash}Fock exchange stabilize occupied MOs strongly and destabilize virtual MOs. HOMO-LUMO gaps are nearly doubled as a result. The previously noted {open_quotes}dramatic influence{close_quotes} of different exchange-correlation (XC) functionals on the calculated chemical shifts is analyzed. The influence of the XC functional is realized through the paramagnetic part of the shielding; hybrid functionals increase it in absolute terms as compared to pure DFT (GGA). It is argued that three factors are responsible. These are (i) the increased occupied-virtual gaps, (ii) the more diffuse nature of virtual orbitals, and (iii) the coupling due to the Hartree{endash}Fock exchange in hybrid functionals. The last two factors increase the paramagnetic part of the shielding, and this effect is only partly reversed by the increased occupied-virtual gaps that result in reduced interactions. It is suggested

  11. EFFECTS OF DYNAMICAL EVOLUTION OF GIANT PLANETS ON SURVIVAL OF TERRESTRIAL PLANETS

    SciTech Connect

    Matsumura, Soko; Ida, Shigeru; Nagasawa, Makiko

    2013-04-20

    The orbital distributions of currently observed extrasolar giant planets allow marginally stable orbits for hypothetical, terrestrial planets. In this paper, we propose that many of these systems may not have additional planets on these ''stable'' orbits, since past dynamical instability among giant planets could have removed them. We numerically investigate the effects of early evolution of multiple giant planets on the orbital stability of the inner, sub-Neptune-like planets which are modeled as test particles, and determine their dynamically unstable region. Previous studies have shown that the majority of such test particles are ejected out of the system as a result of close encounters with giant planets. Here, we show that secular perturbations from giant planets can remove test particles at least down to 10 times smaller than their minimum pericenter distance. Our results indicate that, unless the dynamical instability among giant planets is either absent or quiet like planet-planet collisions, most test particles down to {approx}0.1 AU within the orbits of giant planets at a few AU may be gone. In fact, out of {approx}30% of survived test particles, about three quarters belong to the planet-planet collision cases. We find a good agreement between our numerical results and the secular theory, and present a semi-analytical formula which estimates the dynamically unstable region of the test particles just from the evolution of giant planets. Finally, our numerical results agree well with the observations, and also predict the existence of hot rocky planets in eccentric giant planet systems.

  12. Production of Star-Grazing and Star-Impacting Planetestimals via Orbital Migration of Extrasolar Planets

    NASA Technical Reports Server (NTRS)

    Quillen, A. C.; Holman, M.

    2000-01-01

    During the orbital migration of a giant extrasolar planet via ejection of planetesimals (as studied by Murray et al. in 1998), inner mean-motion resonances can be strong enough to cause planetesimals to graze or impact the star. We integrate numerically the motions of particles which pass through the 3:1 or 4:1 mean-motion resonances of a migrating Jupiter-mass planet. We find that many particles can be trapped in the 3:1 or 4:1 resonances and pumped to high enough eccentricities that they impact the star. This implies that for a planet migrating a substantial fraction of its semimajor axis, a fraction of its mass in planetesimals could impact the star. This process may be capable of enriching the metallicity of the star at a time when the star is no longer fully convective. Upon close approaches to the star, the surfaces of these planetesimals will be sublimated. Orbital migration should cause continuing production of evaporating bodies, suggesting that this process should be detectable with searches for transient absorption lines in young stars. The remainder of the particles will not impact the star but can be ejected subsequently by the planet as it migrates further inward. This allows the planet to migrate a substantial fraction of its initial semimajor axis by ejecting planetesimals.

  13. On the rotation of co-orbital bodies in eccentric orbits

    NASA Astrophysics Data System (ADS)

    Leleu, A.; Robutel, P.; Correia, A. C. M.

    2016-06-01

    We investigate the resonant rotation of co-orbital bodies in eccentric and planar orbits. We develop a simple analytical model to study the impact of the eccentricity and orbital perturbations on the spin dynamics. This model is relevant in the entire domain of horseshoe and tadpole orbit, for moderate eccentricities. We show that there are three different families of spin-orbit resonances, one depending on the eccentricity, one depending on the orbital libration frequency, and another depending on the pericenter's dynamics. We can estimate the width and the location of the different resonant islands in the phase space, predicting which are the more likely to capture the spin of the rotating body. In some regions of the phase space the resonant islands may overlap, giving rise to chaotic rotation.

  14. The VLT/NaCo large program to probe the occurrence of exoplanets and brown dwarfs at wide orbits . III. The frequency of brown dwarfs and giant planets as companions to solar-type stars

    NASA Astrophysics Data System (ADS)

    Reggiani, M.; Meyer, M. R.; Chauvin, G.; Vigan, A.; Quanz, S. P.; Biller, B.; Bonavita, M.; Desidera, S.; Delorme, P.; Hagelberg, J.; Maire, A.-L.; Boccaletti, A.; Beuzit, J.-L.; Buenzli, E.; Carson, J.; Covino, E.; Feldt, M.; Girard, J.; Gratton, R.; Henning, T.; Kasper, M.; Lagrange, A.-M.; Mesa, D.; Messina, S.; Montagnier, G.; Mordasini, C.; Mouillet, D.; Schlieder, J. E.; Segransan, D.; Thalmann, C.; Zurlo, A.

    2016-02-01

    Context. In recent years there have been many attempts to characterize the occurrence and distribution of stellar, brown dwarf (BD), and planetary-mass companions to solar-type stars with the aim of constraining formation mechanisms. From radial velocity observations a dearth of companions with masses between 10-40 MJupiter has been noticed at close separations, suggesting the possibility of a distinct formation mechanism for objects above and below this range. Aims: We present a model for the substellar companion mass function (CMF). This model consists of the superposition of the planet and BD companion mass distributions, assuming that we can extrapolate the radial velocity measured CMF for planets to larger separations and the stellar companion mass-ratio distribution over all separations into the BD mass regime. By using both the results of the VLT/NaCo large program (NaCo-LP) and the complementary archive datasets, which probe the occurrence of planets and BDs on wide orbits around solar-type stars, we place some constraints on the planet and BD distributions. Methods: We developed a Monte Carlo simulation tool to predict the outcome of a given survey, depending on the shape of the orbital parameter distributions (mass, semimajor axis, eccentricity, and inclination). Comparing the predictions with the results of the observations, we calculate the likelihood of different models and which models can be ruled out. Results: Current observations are consistent with the proposed model for the CMF, as long as a sufficiently small outer truncation radius (≲100 AU) is introduced for the planet separation distribution. Some regions of parameter space can be excluded by the observations. Conclusions: We conclude that the results of the direct imaging surveys searching for substellar companions around Sun-like stars are consistent with a combined substellar mass spectrum of planets and BDs. This mass distribution has a minimum between 10 and 50 MJupiter, in agreement

  15. The Metallicity of Giant Planets

    NASA Astrophysics Data System (ADS)

    Thorngren, Daniel P.; Fortney, Jonathan

    2015-12-01

    Unique clues about the formation processes of giant planets can be found in their bulk compositions. Transiting planets provide us with bulk density determinations that can then be compared to models of planetary structure and evolution, to deduce planet bulk metallicities. At a given mass, denser planets have a higher mass fraction of metals. However, the unknown hot Jupiter "radius inflation" mechanism leads to under-dense planets that severely biases this work. Here we look at cooler transiting gas giants (Teff < 1000 K), which do not exhibit the radius inflation effect seen in their warmer cousins. We identified 40 such planets between 20 M_Earth and 20 M_Jup from the literature and used evolution models to determine their bulk heavy-element ("metal") mass. Several important trends are apparent. We see that all planets have at least ~10 M_Earth of metals, and that the mass of metal correlates strongly with the total mass of the planet. The heavy-element mass goes as the square root of the total mass. Both findings are consistent with the core accretion model. We also examined the effect of the parent star metallicity [Fe/H], finding that planets around high-metallicity stars are more likely to have large amounts of metal, but the relation appears weaker than previous studies with smaller sample sizes had suggested. We also looked for connections between bulk composition and planetary orbital parameters and stellar parameters, but saw no pattern, which is also an important result. This work can be directly compared to current and future outputs from planet formation models, including population synthesis.

  16. Hydrodynamic Simulations of Giant Impacts

    NASA Astrophysics Data System (ADS)

    Reinhardt, Christian; Stadel, Joachim

    2013-07-01

    We studied the basic numerical aspects of giant impacts using Smoothed Particles Hydrodynamics (SPH), which has been used in most of the prior studies conducted in this area (e.g., Benz, Canup). Our main goal was to modify the massive parallel, multi-stepping code GASOLINE widely used in cosmological simulations so that it can properly simulate the behavior of condensed materials such as granite or iron using the Tillotson equation of state. GASOLINE has been used to simulate hundreds of millions of particles for ideal gas physics so that using several millions of particles in condensed material simulations seems possible. In order to focus our attention of the numerical aspects of the problem we neglected the internal structure of the protoplanets and modelled them as homogenous (isothermal) granite spheres. For the energy balance we only considered PdV work and shock heating of the material during the impact (neglected cooling of the material). Starting at a low resolution of 2048 particles for the target and the impactor we run several simulations for different impact parameters and impact velocities and successfully reproduced the main features of the pioneering work of Benz from 1986. The impact sends a shock wave through both bodies heating the target and disrupting the remaining impactor. As in prior simulations material is ejected from the collision. How much, and whether it leaves the system or survives in an orbit for a longer time, depends on the initial conditions but also on resolution. Increasing the resolution (to 1.2x10⁶ particles) results in both a much clearer shock wave and deformation of the bodies during the impact and a more compact and detailed "arm" like structure of the ejected material. Currently we are investigating some numerical issues we encountered and are implementing differentiated models, making one step closer to more realistic protoplanets in such giant impact simulations.

  17. Giant Congenital Melanocytic Nevi and Neurocutaneous Melanosis

    PubMed Central

    Araújo, Catarina; Pardal, Francisco; Brito, Celeste

    2015-01-01

    Introduction. The major medical concern with giant congenital melanocytic nevi CMN is high risk of developing cutaneous melanoma, leptomeningeal melanoma, and neurocutaneous melanocytosis. Case Report. A 30-year-old woman with a giant congenital melanocytic nevus covering nearly the entire right thoracodorsal region and multiple disseminated melanocytic nevi presented with neurological symptoms. Cerebral magnetic resonance imaging revealed a large expansive lesion in the left frontal region. Postsurgically pathological diagnosis revealed characteristics of melanoma. Immunohistochemical examination showed S100(+), HMB45(+), MelanA(+), and MiTF(+). She received radiotherapy with temozolomide followed by two more chemotherapy cycles with temozolomide. She followed a rapidly progressive course, reflecting widespread leptomeningeal infiltration, and she died of multiorgan failure seven months after diagnosis of cerebral melanoma. Discussion. This patient was diagnosed as having a neurocutaneous melanosis with malignant widespread leptomeningeal infiltration. Diffuse spinal involvement is unusual and is described in only another patient. PMID:25722729

  18. Re-inflated Warm Jupiters around Red Giants

    NASA Astrophysics Data System (ADS)

    Lopez, Eric D.; Fortney, Jonathan J.

    2016-02-01

    Since the discovery of the first transiting hot Jupiters, models have sought to explain the anomalously large radii of highly irradiated gas giants. We now know that the size of hot Jupiter radius anomalies scales strongly with a planet's level of irradiation and numerous models like tidal heating, ohmic dissipation, and thermal tides have since been developed to help explain these inflated radii. In general, however, these models can be grouped into two broad categories: models that directly inflate planetary radii by depositing a fraction of the incident irradiation into the interior and models that simply slow a planet's radiative cooling, allowing it to retain more heat from formation and thereby delay contraction. Here we present a new test to distinguish between these two classes of models. Gas giants orbiting at moderate orbital periods around post-main-sequence stars will experience enormous increases to their irradiation as their host stars move up the sub-giant and red-giant branches. If hot Jupiter inflation works by depositing irradiation into the planet's deep interiors then planetary radii should increase in response to the increased irradiation. This means that otherwise non-inflated gas giants at moderate orbital periods of >10 days can re-inflate as their host stars evolve. Here we explore the circumstances that can lead to the creation of these “re-inflated” gas giants and examine how the existence or absence of such planets can be used to place unique constraints on the physics of the hot Jupiter inflation mechanism. Finally, we explore the prospects for detecting this potentially important undiscovered population of planets.

  19. Giant perigenital seborrheic keratosis

    PubMed Central

    Bandyopadhyay, Debabrata; Saha, Abanti; Mishra, Vivek

    2015-01-01

    Seborrheic keratosis (SK) is a very common benign epidermal proliferation that is prevalent in all races. Most commonly occurring on the trunk, face, scalp, and the extremities, they can occur anywhere on the body except the palms and soles. The most common appearance is that of a very superficial verrucous plaque which appears to be stuck on the surface. Giant lesions are very rare, and their location on the genital area is rarer still. We report here a case of multiple giant SK lesions in a 59-year-old man. PMID:25657917

  20. An Innocent Giant

    PubMed Central

    Solanki, Lakhan Singh; Dhingra, Mandeep; Raghubanshi, Gunjan; Thami, Gurvinder Pal

    2014-01-01

    A cutaneous horn (cornu cutaneum) is a protrusion from the skin composed of a cornified material. It may be associated with a benign, premalignant, or malignant lesion at the base, masking numerous dermatoses. In a 24-year-old female, a giant cutaneous horn arising from a seborrheic keratosis located on the leg is presented. This case has been reported to emphasize that a giant cutaneous horn may also occur in young patients, even in photoprotected areas, and are not always associated with malignancy. PMID:25484426

  1. Giant perigenital seborrheic keratosis.

    PubMed

    Bandyopadhyay, Debabrata; Saha, Abanti; Mishra, Vivek

    2015-01-01

    Seborrheic keratosis (SK) is a very common benign epidermal proliferation that is prevalent in all races. Most commonly occurring on the trunk, face, scalp, and the extremities, they can occur anywhere on the body except the palms and soles. The most common appearance is that of a very superficial verrucous plaque which appears to be stuck on the surface. Giant lesions are very rare, and their location on the genital area is rarer still. We report here a case of multiple giant SK lesions in a 59-year-old man. PMID:25657917

  2. Optical Spectra of Extrasolar Giant Planets

    NASA Technical Reports Server (NTRS)

    Heap, Sara R.; Hubeny, Ivan; Sudarsky, David; Burrows, Adam

    2004-01-01

    The flux distribution of a planet relative to its host star is a critical quantity for planning space observatories to detect and characterize extrasolar giant planets (EGP's). In this paper, we present optical planet-star contrasts of Jupiter-mass planets as a function of stellar type, orbital distance, and planetary cloud characteristics. As originally shown by Sudarsky et al. (2000, 2003), the phaseaveraged brightness of an EGP does not necessarily decrease monotonically with greater orbital distance because of changes in its albedo and absorption spectrum at lower temperatures. We apply our results to Eclipse, a 1.8-m optical telescope + coronograph to be proposed as a NASA Discovery mission later this year.

  3. Giant impacts on a primitive Uranus

    NASA Technical Reports Server (NTRS)

    Slattery, Wayne L.; Benz, Willy; Cameron, A. G. W.

    1992-01-01

    Simulations of collisions are conducted between a model of the primitive Uranus and 1-3 earth-mass impactors, using smooth-particle hydrodynamics. A series of collisions was simulated for each impactor while varying the total angular momentum of the system. Most of the simulation runs left ices in orbit; a subset of the runs also left rock or iron (from the impactor). It is concluded on the basis of these results that there is a wide range of giant impacts which could have produced the current period and inclination of the spin axis relative to the plane of the ecliptic. A subset of these could have deposited the material in orbit from which the regular satellites of Uranus were assembled.

  4. PLUTINO DETECTION BIASES, INCLUDING THE KOZAI RESONANCE

    SciTech Connect

    Lawler, S. M.; Gladman, B.

    2013-07-01

    Because of their relative proximity within the trans-Neptunian region, the plutinos (objects in the 3:2 mean-motion resonance with Neptune) are numerous in flux-limited catalogs, and well-studied theoretically. We perform detailed modeling of the on-sky detection biases for plutinos, with special attention to those that are simultaneously in the Kozai resonance. In addition to the normal 3:2 resonant argument libration, Kozai plutinos also show periodic oscillations in eccentricity and inclination, coupled to the argument of perihelion ({omega}) oscillation. Due to the mean-motion resonance, plutinos avoid coming to pericenter near Neptune's current position in the ecliptic plane. Because Kozai plutinos are restricted to certain values of {omega}, perihelion always occurs out of the ecliptic plane, biasing ecliptic surveys against finding these objects. The observed Kozai plutino fraction f{sub koz}{sup obs} has been measured by several surveys, finding values between 8% and 25%, while the true Kozai plutino fraction f{sub koz}{sup true} has been predicted to be between 10% and 30% by different giant planet migration simulations. We show that f{sub koz}{sup obs} varies widely depending on the ecliptic latitude and longitude of the survey, so debiasing to find the true ratio is complex. Even a survey that covers most or all of the sky will detect an apparent Kozai fraction that is different from f{sub koz}{sup true}. We present a map of the on-sky plutino Kozai fraction that would be detected by all-sky flux-limited surveys. This will be especially important for the Panoramic Survey Telescope and Rapid Response System and Large Synoptic Survey Telescope projects, which may detect large numbers of plutinos as they sweep the sky. f{sub koz}{sup true} and the distribution of the orbital elements of Kozai plutinos may be a diagnostic of giant planet migration; future migration simulations should provide details on their resonant Kozai populations.

  5. Orbiter's Skeleton

    NASA Technical Reports Server (NTRS)

    2005-01-01

    The structure of NASA's Mars Reconnaissance Orbiter spacecraft is constructed from composite panels of carbon layers over aluminum honeycomb, lightweight yet strong. This forms a basic structure or skeleton on which the instruments, electronics, propulsion and power systems can be mounted. The propellant tank is contained in the center of the orbiter's structure. This photo was taken at Lockheed Martin Space Systems, Denver, during construction of the spacecraft.

  6. The kinematics of halo red giants

    NASA Astrophysics Data System (ADS)

    Carney, B. W.; Latham, D. W.

    1986-07-01

    The authors have obtained 337 radial velocities with typical accuracies of ± 0.7 km s-1 for 85 metal-poor field red giants, selected from the kinematically unbiased samples of Bond (1980) and Bidelman and MacConnell (1973). The multiply observed stars suggest the field halo giant binary fraction exceeds 10%. Using their own velocities and those published by others, the authors have a sample of 174 red giants with [Fe/H] ≤ -1.5. Their mean motion with respect to the local standard of rest is >V< = -206±23 km s-1, and the velocity dispersions are σR = 154±18 km s-1, σθ = 102±27 km s-1, and σφ = 107±15 km s-1. Using photometrically derived absolute magnitudes and published proper motions, the authors compute orbital eccentricities for 72 stars not already considered in a similar study of southern stars by Norris, Bessell, and Pickles (1985). They find a few (5% - 8%) stars with e < 0.4.

  7. Giant spin Hall effect in graphene grown by chemical vapour deposition

    NASA Astrophysics Data System (ADS)

    Balakrishnan, Jayakumar; Koon, Gavin Kok Wai; Avsar, Ahmet; Ho, Yuda; Lee, Jong Hak; Jaiswal, Manu; Baeck, Seung-Jae; Ahn, Jong-Hyun; Ferreira, Aires; Cazalilla, Miguel A.; Neto, Antonio H. Castro; Özyilmaz, Barbaros

    2014-09-01

    Advances in large-area graphene synthesis via chemical vapour deposition on metals like copper were instrumental in the demonstration of graphene-based novel, wafer-scale electronic circuits and proof-of-concept applications such as flexible touch panels. Here, we show that graphene grown by chemical vapour deposition on copper is equally promising for spintronics applications. In contrast to natural graphene, our experiments demonstrate that chemically synthesized graphene has a strong spin-orbit coupling as high as 20 meV giving rise to a giant spin Hall effect. The exceptionally large spin Hall angle ~0.2 provides an important step towards graphene-based spintronics devices within existing complementary metal-oxide-semiconductor technology. Our microscopic model shows that unavoidable residual copper adatom clusters act as local spin-orbit scatterers and, in the resonant scattering limit, induce transverse spin currents with enhanced skew-scattering contribution. Our findings are confirmed independently by introducing metallic adatoms-copper, silver and gold on exfoliated graphene samples.

  8. Electroluminescence of Giant Stretchability.

    PubMed

    Yang, Can Hui; Chen, Baohong; Zhou, Jinxiong; Chen, Yong Mei; Suo, Zhigang

    2016-06-01

    A new type of electroluminescent device achieves giant stretchability by integrating electronic and ionic components. The device uses phosphor powders as electroluminescent materials, and hydrogels as stretchable and transparent ionic conductors. Subject to cyclic voltage, the phosphor powders luminesce, but the ionic conductors do not electrolyze. The device produces constant luminance when stretched up to an area strain of 1500%. PMID:26610277

  9. A giant ureteric calculus

    PubMed Central

    Rathod, Rajiv; Bansal, Prashant; Gutta, Srinivas

    2013-01-01

    Ureteric stones are usually small and symptomatic. We present a case of a 35-year old female who presented with minimally symptomatic right distal ureteric calculus with proximal hydroureteronephrosis. Laparoscopic right ureterolithotomy was performed and a giant ureteric calculus measuring 11 cm Χ 1.5 cm, weighing 40 g was retrieved. PMID:24082453

  10. Giant urethral calculus

    PubMed Central

    Kotkar, Kunal; Thakkar, Ravi; Songra, MC

    2011-01-01

    Primary urethral calculus is rarely seen and is usually encountered in men with urethral stricture or diverticulum. We present a case of giant urethral calculus secondary to a urethral stricture in a man. The patient was treated with calculus extraction with end to end urethroplasty. PMID:24950400

  11. Juvenile giant fibroadenoma

    PubMed Central

    Yagnik, Vipul D.

    2011-01-01

    Fibroadenomas are benign solid tumor associated with aberration of normal lobular development. Juvenile giant fibroadenoma is usually single and >5 cm in size /or >500 gms in weight. Important differential diagnoses are: phyllodes tumor and juvenile gigantomastia. Simple excision is the treatment of choice. PMID:24765310

  12. A giant ureteric calculus.

    PubMed

    Rathod, Rajiv; Bansal, Prashant; Gutta, Srinivas

    2013-07-01

    Ureteric stones are usually small and symptomatic. We present a case of a 35-year old female who presented with minimally symptomatic right distal ureteric calculus with proximal hydroureteronephrosis. Laparoscopic right ureterolithotomy was performed and a giant ureteric calculus measuring 11 cm Χ 1.5 cm, weighing 40 g was retrieved. PMID:24082453

  13. Giant proximity effect in cuprate superconductors.

    PubMed

    Bozovic, I; Logvenov, G; Verhoeven, M A J; Caputo, P; Goldobin, E; Beasley, M R

    2004-10-01

    Using an advanced molecular beam epitaxy system, we have reproducibly synthesized atomically smooth films of high-temperature superconductors and uniform trilayer junctions with virtually perfect interfaces. We found that supercurrent runs through very thick barriers. We can rule out pinholes and microshorts; this "giant proximity effect" (GPE) is intrinsic. It defies the conventional explanation; it might originate in resonant tunneling through pair states in an almost-superconducting barrier. GPE may also be significant for superconducting electronics, since thick barriers are easier to fabricate. PMID:15524925

  14. Pervasive orbital eccentricities dictate the habitability of extrasolar earths.

    PubMed

    Kita, Ryosuke; Rasio, Frederic; Takeda, Genya

    2010-09-01

    The long-term habitability of Earth-like planets requires low orbital eccentricities. A secular perturbation from a distant stellar companion is a very important mechanism in exciting planetary eccentricities, as many of the extrasolar planetary systems are associated with stellar companions. Although the orbital evolution of an Earth-like planet in a stellar binary system is well understood, the effect of a binary perturbation on a more realistic system containing additional gas-giant planets has been very little studied. Here, we provide analytic criteria confirmed by a large ensemble of numerical integrations that identify the initial orbital parameters leading to eccentric orbits. We show that an extrasolar earth is likely to experience a broad range of orbital evolution dictated by the location of a gas-giant planet, which necessitates more focused studies on the effect of eccentricity on the potential for life. PMID:20879864

  15. Spin polarized surface resonance bands in single layer Bi on Ge(1 1 1)

    NASA Astrophysics Data System (ADS)

    Bottegoni, F.; Calloni, A.; Bussetti, G.; Camera, A.; Zucchetti, C.; Finazzi, M.; Duò, L.; Ciccacci, F.

    2016-05-01

    The spin features of surface resonance bands in single layer Bi on Ge(1 1 1) are studied by means of spin- and angle-resolved photoemission spectroscopy and inverse photoemission spectroscopy. We characterize the occupied and empty surface states of Ge(1 1 1) and show that the deposition of one monolayer of Bi on Ge(1 1 1) leads to the appearance of spin-polarized surface resonance bands. In particular, the C 3v symmetry, which Bi adatoms adopt on Ge(1 1 1), allows for the presence of Rashba-like occupied and unoccupied electronic states around the \\overline{\\text{M}} point of the Bi surface Brillouin zone with a giant spin–orbit constant |{α\\text{R}}| =≤ft(1.4+/- 0.1\\right) eV · Å.

  16. Spin polarized surface resonance bands in single layer Bi on Ge(1 1 1).

    PubMed

    Bottegoni, F; Calloni, A; Bussetti, G; Camera, A; Zucchetti, C; Finazzi, M; Duò, L; Ciccacci, F

    2016-05-18

    The spin features of surface resonance bands in single layer Bi on Ge(1 1 1) are studied by means of spin- and angle-resolved photoemission spectroscopy and inverse photoemission spectroscopy. We characterize the occupied and empty surface states of Ge(1 1 1) and show that the deposition of one monolayer of Bi on Ge(1 1 1) leads to the appearance of spin-polarized surface resonance bands. In particular, the C 3v symmetry, which Bi adatoms adopt on Ge(1 1 1), allows for the presence of Rashba-like occupied and unoccupied electronic states around the [Formula: see text] point of the Bi surface Brillouin zone with a giant spin-orbit constant [Formula: see text] eV · Å. PMID:27073190

  17. Orbit Prediction Tool for Different Classes of Space Debris Orbits

    NASA Astrophysics Data System (ADS)

    Wnuk, Edwin; Wytrzyszczak, Iwona; Golembiewska, Justyna; Klinkrad, Heiner

    once per given orbital arc (with a arc different lengths for different orbital classes, usually a few days long). Only those amplitudes that essentially influence the perturbation (usually a few percent) are stored for further calculations. For each of the orbits we also determine "a reso-nance indicator". In the case of resonance the resonance terms are selected. In a second step, applying simple formulas and using the stored values of amplitudes, predicted positions for given epochs are calculated. For resonance orbits only the non-resonant terms are included in this entirely analytical algorithm. Early separated resonance terms of the perturbing function are included into another algorithm for the calculation of perturbations on a basis of numerical integration. Solar radiation pressure perturbations in orbital elements are determined with the use of a newly developed analytical theory that enables relatively simple calculations of these perturbations for given epochs. The paper will present the model of the prediction tool and several examples of future space debris trajectories determination for different classes of orbit including LEO, MEO, HEO and GEO.

  18. Capture of terrestrial-sized moons by gas giant planets.

    PubMed

    Williams, Darren M

    2013-04-01

    Terrestrial moons with masses >0.1 M (symbol in text) possibly exist around extrasolar giant planets, and here we consider the energetics of how they might form. Binary-exchange capture can occur if a binary-terrestrial object (BTO) is tidally disrupted during a close encounter with a giant planet and one of the binary members is ejected while the other remains as a moon. Tidal disruption occurs readily in the deep gravity wells of giant planets; however, the large encounter velocities in the wells make binary exchange more difficult than for planets of lesser mass. In addition, successful capture favors massive binaries with large rotational velocities and small component mass ratios. Also, since the interaction tends to leave the captured moons on highly elliptical orbits, permanent capture is only possible around planets with sizable Hill spheres that are well separated from their host stars. PMID:23537110

  19. The Consumption of Giant Planets by Subgiant Stars

    NASA Astrophysics Data System (ADS)

    Dokter, J.; Sandquist, E.; Lin, D.; Burkert, A.

    2000-05-01

    We conduct simulations of the hydrodynamical interaction between giant planets and evolved stars of approximately solar mass with the purpose of testing the observability of signatures of the merger process. As the evolution of the host star pushes its surface outward in radius, it can begin to strongly interact with planets that were on orbits farther and farther from the star. The evolutionary state of the star affects the depth to which the giant star penetrates before evaporating, the amount of dilution or burning of the planet's chemical contaminants, and the disturbance of the star's envelope. In this study, we will look at observable consequences of star-planet interactions (Siess & Livio 1999a,b) while the star is in the subgiant phase --- particularly lithium abundances observed in giant stars, stellar rotation, and infrared excesses. We would like to thank Compaq for supplying the computer hardware that was used to carry out this project.

  20. Management of giant pseudomeningoceles after spinal surgery

    PubMed Central

    2010-01-01

    Background Pseudomeningoceles are a rare complication after spinal surgery, and studies on these complex formations are few. Methods Between October 2000 and March 2008, 11 patients who developed symptomatic pseudomeningoceles after spinal surgery were recruited. In this retrospective study, we reported our experiences in the management of these complex, symptomatic pseudomeningoceles after spinal surgery. A giant pseudomeningocele was defined as a pseudomeningocele >8 cm in length. We also evaluated the risk factors for the formation of giant pseudomeningoceles. Results All patients were treated successfully with a combined treatment protocol of open revision surgery for extirpation of the pseudomeningoceles, repair of dural tears, and implantation of a subarachnoid catheter for drainage. Surgery-related complications were not observed. Recurrence of pseudomeningocele was not observed for any patient at a mean follow-up of 16.5 months. This result was confirmed by magnetic resonance imaging. Conclusions We conclude that a combined treatment protocol involving open revision surgery for extirpation of pseudomeningoceles, repair of dural tears, and implantation of a subarachnoid catheter for drainage is safe and effective to treat giant pseudomeningoceles. PMID:20302667

  1. Giant plexiform neurofibroma and suboccipital meningocele manifesting as segmental neurofibromatosis.

    PubMed

    Kurimoto, Masanori; Mizumaki, Yasushi; Fukuda, Osamu; Hayashi, Nakamasa; Kuwayama, Naoya; Endo, Shunro

    2008-06-01

    A 34-year-old woman presented with segmental neurofibromatosis manifesting as a soft lump with a large café-au-lait macule on her occipital region and neck. Magnetic resonance imaging showed a thick skin tumor in the occipital region and posterior neck, and a suboccipital meningocele which seemed to have no association with her symptoms. Biopsy lead to a histological diagnosis of giant plexiform neurofibroma. During biopsy, massive local bleeding occurred and hemostasis was achieved by electrocautery and meticulous suture ligation. The postoperative course was uneventful and observation was continued for both the giant plexiform neurofibroma and the meningocele. PMID:18574335

  2. Orbital cellulitis.

    PubMed Central

    Martin-Hirsch, D P; Habashi, S; Hinton, A H; Kotecha, B

    1992-01-01

    Orbital cellulitis is an emergency. It may cause blindness and progress to life-threatening sequelae such as brain abscess, meningitis and cavernous sinus thrombosis. Successful management is dependent upon urgent referral and immediate treatment. Although isolated eyelid erythema and swelling usually indicate primary infection anterior to the orbital septum, they may also be the first signs of an underlying frontal or ethmoidal sinusitis. The condition always requires emergency referral to both an ophthalmologist and otorhinolaryngologist. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:1388488

  3. Orbital Debris

    NASA Technical Reports Server (NTRS)

    Kessler, D. J. (Compiler); Su, S. Y. (Compiler)

    1985-01-01

    Earth orbital debris issues and recommended future activities are discussed. The workshop addressed the areas of environment definition, hazards to spacecraft, and space object management. It concluded that orbital debris is a potential problem for future space operations. However, before recommending any major efforts to control the environment, more data are required. The most significant required data are on the population of debris smaller than 4 cm in diameter. New damage criteria are also required. When these data are obtained, they can be combined with hypervelocity data to evaluate the hazards to future spacecraft. After these hazards are understood, then techniques to control the environment can be evaluated.

  4. The fate of the earth in the red giant envelope of the sun

    NASA Technical Reports Server (NTRS)

    Goldstein, J.

    1987-01-01

    The effect on the earth of entering the red giant envelope of the future sun is studied. Employing a 30-zone red giant model, the earth orbital decay timescale, neglecting ablation/vaporization, is determined to be of the order of 200 years, rendering earth survival impossible. The effects of ablation/vaporization processes are found to increase the ballistic coefficient of earth, thereby setting the 200-year decay timescale as an upper limit.

  5. Fermi resonance in optical microcavities

    NASA Astrophysics Data System (ADS)

    Yi, Chang-Hwan; Yu, Hyeon-Hye; Lee, Ji-Won; Kim, Chil-Min

    2015-04-01

    Fermi resonance is a phenomenon of quantum mechanical superposition, which most often occurs between normal and overtone modes in molecular systems that are nearly coincident in energy. We find that scarred resonances in deformed dielectric microcavities are the very phenomenon of Fermi resonance, that is, a pair of quasinormal modes interact with each other due to coupling and a pair of resonances are generated through an avoided resonance crossing. Then the quantum number difference of a pair of quasinormal modes, which is a consequence of quantum mechanical superposition, equals periodic orbits, whereby the resonances are localized on the periodic orbits. We derive the relation between the quantum number difference and the periodic orbits and confirm it in an elliptic, a rectangular, and a stadium-shaped dielectric microcavity.

  6. Red Giants in Eclipsing Binaries as a Benchmark for Asteroseismology

    NASA Astrophysics Data System (ADS)

    Rawls, Meredith L.

    2016-04-01

    Red giants with solar-like oscillations are astrophysical laboratories for probing the Milky Way. The Kepler Space Telescope revolutionized asteroseismology by consistently monitoring thousands of targets, including several red giants in eclipsing binaries. Binarity allows us to directly measure stellar properties independently of asteroseismology. In this dissertation, we study a subset of eight red giant eclipsing binaries observed by Kepler with a range of orbital periods, oscillation behavior, and stellar activity. Two of the systems do not show solar-like oscillations at all. We use a suite of modeling tools to combine photometry and spectroscopy into a comprehensive picture of each star's life. One noteworthy case is a double red giant binary. The two stars are nearly twins, but have one main set of solar-like oscillations with unusually low-amplitude, wide modes, likely due to stellar activity and modest tidal forces acting over the 171 day eccentric orbit. Mixed modes indicate the main oscillating star is on the secondary red clump (a core-He-burning star), and stellar evolution modeling supports this with a coeval history for a pair of red clump stars. The other seven systems are all red giant branch stars (shell-H-burning) with main sequence companions. The two non-oscillators have the strongest magnetic signatures and some of the strongest lifetime tidal forces with nearly-circular 20–34 day orbits. One system defies this trend with oscillations and a 19 day orbit. The four long-period systems (>100 days) have oscillations, more eccentric orbits, and less stellar activity. They are all detached binaries consistent with coevolution. We find the asteroseismic scaling laws are approximately correct, but fail the most for stars that are least like the Sun by systematically overestimating both mass and radius. Strong magnetic activity and tidal effects often occur in tandem and act to suppress solar-like oscillations. These red giant binaries offer an

  7. What Makes Red Giants Tick? Linking Tidal Forces, Activity, and Solar-Like Oscillations via Eclipsing Binaries

    NASA Astrophysics Data System (ADS)

    Rawls, Meredith L.; Gaulme, Patrick; McKeever, Jean; Jackiewicz, Jason

    2016-01-01

    Thanks to advances in asteroseismology, red giants have become astrophysical laboratories for studying stellar evolution and probing the Milky Way. However, not all red giants show solar-like oscillations. It has been proposed that stronger tidal interactions from short-period binaries and increased magnetic activity on spotty giants are linked to absent or damped solar-like oscillations, yet each star tells a nuanced story. In this work, we characterize a subset of red giants in eclipsing binaries observed by Kepler. The binaries exhibit a range of orbital periods, solar-like oscillation behavior, and stellar activity. We use orbital solutions together with a suite of modeling tools to combine photometry and spectroscopy in a detailed analysis of tidal synchronization timescales, star spot activity, and stellar evolution histories. These red giants offer an unprecedented opportunity to test stellar physics and are important benchmarks for ensemble asteroseismology.

  8. Observation of a hybrid spin resonance

    PubMed

    Bai; Allgower; Ahrens; Alessi; Brown; Bunce; Cameron; Chu; Courant; Glenn; Huang; Jeon; Kponou; Krueger; Luccio; Makdisi; Lee; Ratner; Reece; Roser; Spinka; Syphers; Tsoupas; Underwood; van Asselt W; Williams

    2000-02-01

    A new type of spin depolarization resonance has been observed at the Brookhaven Alternating Gradient Synchrotron (AGS). This spin resonance is identified as a strong closed-orbit sideband around the dominant intrinsic spin resonance. The strength of the resonance was proportional to the 9th harmonic component of the horizontal closed orbit and proportional to the vertical betatron oscillation amplitude. This "hybrid" spin resonance cannot be overcome by the partial snake at the AGS, but it can be corrected by the harmonic orbit correctors. PMID:11017474

  9. A giant vesical calculus.

    PubMed

    Rahman, M; Uddin, A; Das, G C; Akanda, N I

    2007-07-01

    Massive or giant vesical calculus is a rare entity in the recent urological practice. Males are affected more than the females. Vesical calculi are usually secondary to bladder outlet obstruction. These patients present with recurrent urinary tract infection, haematuria or with retention of urine. We report a young male patient who presented with defaecatory problems along with other urinary symptoms. The patient having an average built, non diabetic but hypertensive. The stone could be palpated by physical examination. His urea levels were within normal limits but urine examination shows infection. USG reveals bilateral hydronephrosis with multiple stones in both kidneys along with a giant vesical calculus. After controlling urinary infection and hypertention he underwent an open cystolithotomy. During operation digital rectal help was needed to remove the stone as it was adherent with bladder mucosa. Post operative period was uneventful. His urinary output was quite normal and had no defaecatory problems. Patient left the hospital 10 days after operation. PMID:17917633

  10. Kepler-108: A Mutually Inclined Giant Planet System

    NASA Astrophysics Data System (ADS)

    Mills, Sean M.; Fabrycky, Daniel

    2016-06-01

    The vast majority of well studied giant-planet systems, including the Solar System, are nearly coplanar which implies dissipation within a primordial gas disk. However, intrinsic instability may lead to planet-planet scattering, which often produces non-coplanar, eccentric orbits. Planet scattering theories have been developed to explain observed high eccentricity systems and possibly hot Jupiters; thus far their predictions for mutual inclination (I) have barely been tested. Here we characterize a highly mutually-inclined (I ~ 15-60 degrees), moderately eccentric (e > 0.1) giant planet system: Kepler-108. This system consists of two Saturn mass planets with periods of ~49 and ~190 days around a star with a wide (~300 AU) binary companion in an orbital configuration inconsistent with a purely disk migration origin.

  11. Ice Giant Exploration

    NASA Astrophysics Data System (ADS)

    Rymer, A. M.; Arridge, C. S.; Masters, A.; Turtle, E. P.; Simon, A. A.; Hofstadter, M. D.; Turrini, D.; Politi, R.

    2015-12-01

    The Ice Giants in our solar system, Uranus and Neptune, are fundamentally different from their Gas Giant siblings Jupiter and Saturn, from the different proportions of rock and ice to the configuration of their planetary magnetic fields. Kepler space telescope discoveries of exo-planets indicate that planets of this type are among the most ubiquitous universally and therefore a future mission to explore the nature of the Ice Giants in our own solar system will provide insights into the nature of extra-solar system objects in general. Uranus has the smallest self- luminosity of all the planets, potentially related to catastrophic events early in the planet's history, which also may explain Uranus' large obliquity. Uranus' atmosphere is subject to extreme seasonal forcing making it unique in the Solar System. Neptune is also unique in a number of ways, notably its large moon Triton which is likely a captured Kuiper Belt Object and one of only two moons in the solar system with a robustly collisional atmosphere. Similar to Uranus, the angle between the solar wind and the magnetic dipole axis is subject to large-amplitude variations on both diurnal and seasonal timescales, but peculiarly it has one of the quietest magnetospheres of the solar system, at least according to Voyager 2, the only spacecraft to encounter Neptune to date. A comprehensive mission, as advocated in the Decadal Survey, would provide enormous science return but is also challenging and expensive. In this presentation we will discuss mission scenarios and suggest how collaboration between disciplines and internationally can help us to pursue a mission that includes Ice Giant exploration.

  12. Giant thymic carcinoid.

    PubMed

    John, L C; Hornick, P; Lang, S; Wallis, J; Edmondson, S J

    1991-05-01

    Thymic carcinoid is a rare tumour. It may present with ectopic endocrine secretion or with symptoms of compression as a result of its size. A case is reported which presented with symptoms of compression where the size of the tumour was uniquely large such as to warrant the term giant thymic carcinoid. The typical histological features are described, together with its possible origin and its likely prognosis. PMID:1852667

  13. Giant dedifferentiated retroperitoneal liposarcoma.

    PubMed

    Dominguez, Elias; Lopez de Cenarruzabeitia, Iñigo; Martinez, Manuel; Rueda, J C; Lede, A; Barreiro, Erica; Diz, Susana

    2008-01-01

    Liposarcoma tumors only represent 0.1% of all cancers, but they are the more common of retroperitoneal sarcomas. It has a great tendency for local recurrence, mainly the dedifferentiated variety, but its complete resection can provide a 5-year survival of 70%. In this report, we present a case of a giant dedifferentiated retroperitoneal liposarcoma that did not affect any neighboring organ and that was successfully treated by means of complete surgical resection. PMID:19731863

  14. Giant rodlike reversed micelles

    SciTech Connect

    Yu, Z.J.; Neuman, R.D. )

    1994-05-04

    Herein we report that sodium bis(2-ethylhexyl)phosphate, which is similar in structure to the classical surfactant sodium bis(2-ethylhexyl)sulfosuccinate (AOT), forms very large rodlike reversed micelles and that their size can be even much larger if water is removed from the apolar solution. We further suggest that long-range electrostatic interactions are the primary driving force for the formation of giant reversed micelles. 19 refs., 3 figs.

  15. Giant cell arteritis

    PubMed Central

    Calvo-Romero, J

    2003-01-01

    Giant cell arteritis (GCA), temporal arteritis or Horton's arteritis, is a systemic vasculitis which involves large and medium sized vessels, especially the extracranial branches of the carotid arteries, in persons usually older than 50 years. Permanent visual loss, ischaemic strokes, and thoracic and abdominal aortic aneurysms are feared complications of GCA. The treatment consists of high dose steroids. Mortality, with a correct treatment, in patients with GCA seems to be similar that of controls. PMID:13679546

  16. Red giants seismology

    NASA Astrophysics Data System (ADS)

    Mosser, B.; Samadi, R.; Belkacem, K.

    2013-11-01

    The space-borne missions CoRoT and Kepler are indiscreet. With their asteroseismic programs, they tell us what is hidden deep inside the stars. Waves excited just below the stellar surface travel throughout the stellar interior and unveil many secrets: how old is the star, how big, how massive, how fast (or slow) its core is dancing. This paper intends to paparazze the red giants according to the seismic pictures we have from their interiors.

  17. Long term evolution of planetary systems with a terrestrial planet and a giant planet

    NASA Astrophysics Data System (ADS)

    Georgakarakos, Nikolaos; Dobbs-Dixon, Ian; Way, Michael J.

    2016-06-01

    We study the long term orbital evolution of a terrestrial planet under the gravitational perturbations of a giant planet. In particular, we are interested in situations where the two planets are in the same plane and are relatively close. We examine both possible configurations: the giant planet orbit being either outside or inside the orbit of the smaller planet. The perturbing potential is expanded to high orders and an analytical solution of the terrestrial planetary orbit is derived. The analytical estimates are then compared against results from the numerical integration of the full equations of motion and we find that the analytical solution works reasonably well. An interesting finding is that the new analytical estimates improve greatly the predictions for the timescales of the orbital evolution of the terrestrial planet compared to an octupole order expansion. Finally, we briefly discuss possible applications of the analytical estimates in astrophysical problems.

  18. Long-term evolution of planetary systems with a terrestrial planet and a giant planet

    NASA Astrophysics Data System (ADS)

    Georgakarakos, Nikolaos; Dobbs-Dixon, Ian; Way, Michael J.

    2016-09-01

    We study the long-term orbital evolution of a terrestrial planet under the gravitational perturbations of a giant planet. In particular, we are interested in situations where the two planets are in the same plane and are relatively close. We examine both possible configurations: the giant planet orbit being either outside or inside the orbit of the smaller planet. The perturbing potential is expanded to high orders, and an analytical solution of the terrestrial planetary orbit is derived. The analytical estimates are then compared against results from the numerical integration of the full equations of motion, and we find that the analytical solution works reasonably well. An interesting finding is that the new analytical estimates improve greatly the predictions for the time-scales of the orbital evolution of the terrestrial planet compared to an octupole order expansion. Finally, we briefly discuss possible applications of the analytical estimates in astrophysical problems.

  19. EFFECTS OF TURBULENCE, ECCENTRICITY DAMPING, AND MIGRATION RATE ON THE CAPTURE OF PLANETS INTO MEAN MOTION RESONANCE

    SciTech Connect

    Ketchum, Jacob A.; Adams, Fred C.; Bloch, Anthony M.

    2011-01-01

    Pairs of migrating extrasolar planets often lock into mean motion resonance as they drift inward. This paper studies the convergent migration of giant planets (driven by a circumstellar disk) and determines the probability that they are captured into mean motion resonance. The probability that such planets enter resonance depends on the type of resonance, the migration rate, the eccentricity damping rate, and the amplitude of the turbulent fluctuations. This problem is studied both through direct integrations of the full three-body problem and via semi-analytic model equations. In general, the probability of resonance decreases with increasing migration rate, and with increasing levels of turbulence, but increases with eccentricity damping. Previous work has shown that the distributions of orbital elements (eccentricity and semimajor axis) for observed extrasolar planets can be reproduced by migration models with multiple planets. However, these results depend on resonance locking, and this study shows that entry into-and maintenance of-mean motion resonance depends sensitively on the migration rate, eccentricity damping, and turbulence.

  20. Giant radio pulses

    NASA Astrophysics Data System (ADS)

    Kondratiev, Vladislav

    Rotation-powered radio pulsars exhibit a remarkably diverse spectrum of variability with characteristic time scales from days and even years (intermittent pulsars) to minutes-seconds (nulling) and (sub-)microseconds. The latter time scales are associated with the phenomenon of giant pulses (GPs) and micropulses. The story of GPs started in 1968, when Staelin and Reifenstein discovered the Crab pulsar through its spectacularly bright radio pulses. To date, only seven pulsars out of more than 2200 are known to show GP emission, namely the pulsars B0531+21, B1937+21, B0540-69, B1821-24, B1957+20, J0218+4232, and B1820-30A. Giant pulses are characterized by large energies (more than ten times of the energy of the average pulse), short durations, power-law energy distribution, specific rotational phase of occurrence, high degree of polarization, and accompanying high-energy radiation. Large energies of GPs and coincidence of their phase of occurrence with peaks of high-energy profiles hint at the same mechanism of radio GP and high-energy emission. The correlation of Crab pulsar GPs with optical, X-ray and gamma-ray photons was studied for the past 20 years, with only radio/optical link confirmed so far. In my talk I will present the summary of the observational evidence of radio GPs and give an overview of theoretical advances on giant-pulse emission mechanism.

  1. Corralling a Distant Planet with Extreme Resonant Kuiper Belt Objects

    NASA Astrophysics Data System (ADS)

    Malhotra, Renu; Volk, Kathryn; Wang, Xianyu

    2016-06-01

    The four longest period Kuiper Belt objects have orbital periods close to integer ratios with each other. A hypothetical planet with an orbital period of ˜17,117 years and a semimajor axis ˜665 au would have N/1 and N/2 period ratios with these four objects. The orbital geometries and dynamics of resonant orbits constrain the orbital plane, the orbital eccentricity, and the mass of such a planet as well as its current location in its orbital path.

  2. Corralling a Distant Planet with Extreme Resonant Kuiper Belt Objects

    NASA Astrophysics Data System (ADS)

    Malhotra, Renu; Volk, Kathryn; Wang, Xianyu

    2016-06-01

    The four longest period Kuiper Belt objects have orbital periods close to integer ratios with each other. A hypothetical planet with an orbital period of ∼17,117 years and a semimajor axis ∼665 au would have N/1 and N/2 period ratios with these four objects. The orbital geometries and dynamics of resonant orbits constrain the orbital plane, the orbital eccentricity, and the mass of such a planet as well as its current location in its orbital path.

  3. Adiabatic chaos in the spin orbit problem

    NASA Astrophysics Data System (ADS)

    Benettin, Giancarlo; Guzzo, Massimiliano; Marini, Valerio

    2008-05-01

    We provide evidences that the angular momentum of a symmetric rigid body in a spin orbit resonance can perform large scale chaotic motions on time scales which increase polynomially with the inverse of the oblateness of the body. This kind of irregular precession appears as soon as the orbit of the center of mass is non-circular and the angular momentum of the body is far from the principal directions with minimum (maximum) moment of inertia. We also provide a quantitative explanation of these facts by using the theory of adiabatic invariants, and we provide numerical applications to the cases of the 1:1 and 1:2 spin orbit resonances.

  4. Unusual Giant Prostatic Urethral Calculus

    PubMed Central

    Bello, A.; Maitama, H. Y.; Mbibu, N. H.; Kalayi, G. D.; Ahmed, A.

    2010-01-01

    Giant vesico-prostatic urethral calculus is uncommon. Urethral stones rarely form primarily in the urethra, and they are usually associated with urethral strictures, posterior urethral valve or diverticula. We report a case of a 32-year-old man with giant vesico-prostatic (collar-stud) urethral stone presenting with sepsis and bladder outlet obstruction. The clinical presentation, management, and outcome of the giant prostatic urethral calculus are reviewed. PMID:22091328

  5. Giant Planets in Open Clusters and Binaries: Observational Constraints on Migration

    NASA Astrophysics Data System (ADS)

    Quinn, Samuel N.; White, Russel J.; Latham, David W.; Buchhave, Lars A.; Torres, Guillermo

    2016-01-01

    Some giant planets migrate from their birthplace beyond the ice line to short-period orbits just a fraction of an AU from their host stars. Though many theories have been proposed, it is not yet clear which mechanism is most important for migration, and by extension, in which types of planetary system we can expect a greater prevalence of disruptive gas giant migration. One way to constrain this process is to observe the orbital properties of migrating planets, which are expected to be shaped according to the mode of migration: in general, interaction with the gas disk should produce circular, coplanar orbits, while multi-body processes stir up eccentricities and inclinations. Unfortunately, tidal and magnetic interactions between hot Jupiters and their host stars can obscure these differences by damping eccentricities and inclinations over time, so the most direct constraints will come from difficult-to-observe young systems. Additional constraints on migration can be obtained by observing the architectures of systems containing short-period giant planets: if an outer companion is often responsible for driving migration, there should be a higher incidence of massive companions on wide orbits in hot Jupiter systems than in systems not hosting a short-period giant planet. Further, the properties of these outer companions can help differentiate between multi-body migration mechanisms. We describe two complementary surveys that we have carried out to address these problems. The first, a precise radial-velocity survey in nearby adolescent (100-600 Myr) open clusters, characterizes the orbits of giant planets soon after migration. The second, an adaptive optics imaging survey of hot Jupiter host stars, constrains the population of wide companions in hot Jupiter systems. We present the results from these two surveys and discuss the orbital properties and system architectures of our discoveries in the context of giant planet migration.

  6. Secular resonances with massive asteroids and their impact on the dynamics of small bodies

    NASA Astrophysics Data System (ADS)

    Tsirvoulis, Georgios; Novaković, Bojan; Djošović, Valdimir

    2015-08-01

    The quest for understanding the dynamical structure of the main belt has been a long-lasting endeavor. From the discovery of the Kirkwood gaps and the Hirayama families, to the more recent advances in secular perturbation theory, the refinement of the proper elements and the discovery of the three-body mean-motion resonances, only to name a few, the progress has been immense. Dynamical models coupled with the outbursts in computational power and observations have greatly improved our knowledge of the dynamical evolution of the small bodies in the Solar System.While our set of tools for studying the dynamical porperties of the main belt is believed to be sufficiently complete, our assumptions on how to use them seem to have hindered this effort.The concensus has been that, judging by their mass, only the planets, especially the giant ones, can act as efficient perturbers of the orbits of asteroids. Thus a lot of studies have been made on the locations and effects of secular resonances with the giant planets in different parts of the main belt, explaining among other things the presence of gaps in the distribution of asteroids, strange shapes of some asteroid families and transport mechanisms of asteroids to the near-Earth region.Our work is motivated by the first discovery that a secular resonance with the most massive asteroid, Ceres, is the dominant dynamical mechanism responsible for the post-impact evolution of the Hoffmeister family members. Thus the concensus is wrong. Knowing now, that secular resonances with massive asteroids can be effective on asteroid dynamics, we set out to construct a dynamical map of these resonances across the main belt.Our study is focused on the linear and degree four non-linear secular resonances with the two most massive asteroids (1) Ceres and (4) Vesta. First we determine the locations of these secular resonances in the proper elements space, acquiring an understanding of the potentially affected regions, and then we perform

  7. Eye and orbit ultrasound

    MedlinePlus

    Echography - eye orbit; Ultrasound - eye orbit; Ocular ultrasonography; Orbital ultrasonography ... ophthalmology department of a hospital or clinic. Your eye is numbed with medicine (anesthetic drops). The ultrasound ...

  8. Orbital Characteristics of Planetesimals Captured by Circumplanetary Gas Disks

    NASA Astrophysics Data System (ADS)

    Suetsugu, Ryo; Ohtsuki, Keiji; Fujita, Tetsuya

    2016-06-01

    Sufficiently massive growing giant planets have circumplanetary disks, and the capture of solid bodies by the disks would likely influence the growth of the planets and formation of satellite systems around them. In addition to dust particles that are supplied to the disk with inflowing gas, recent studies suggest the importance of capture of planetesimals whose motion is decoupled from the gas, but the orbital evolution of captured bodies in circumplanetary gas disks has not been studied in detail. In the present work, using three-body orbital integration and analytic calculations, we examine orbital characteristics and subsequent dynamical evolution of planetesimals captured by gas drag from circumplanetary gas disks. We find that the semimajor axes of the planet-centered orbits of planetesimals at the time of permanent capture are smaller than about one-third of the planet's Hill radius in most cases. Typically, captured bodies rapidly spiral into the planet, and the rate of the orbital decay is faster for the retrograde orbits due to the strong headwind from the circumplanetary gas. When a planetesimal captured in a retrograde orbit suffers from sufficiently strong gas drag before spiraling into the planet, its orbit turns to the prograde direction at a radial location that can be explained using the Stokes number. We also find that those captured in certain types of orbits can survive for a long period of time even under gas drag both in the prograde and retrograde cases, which may be important for the origin of irregular satellites of giant planets.

  9. Kepler-36: a pair of planets with neighboring orbits and dissimilar densities.

    PubMed

    Carter, Joshua A; Agol, Eric; Chaplin, William J; Basu, Sarbani; Bedding, Timothy R; Buchhave, Lars A; Christensen-Dalsgaard, Jørgen; Deck, Katherine M; Elsworth, Yvonne; Fabrycky, Daniel C; Ford, Eric B; Fortney, Jonathan J; Hale, Steven J; Handberg, Rasmus; Hekker, Saskia; Holman, Matthew J; Huber, Daniel; Karoff, Christopher; Kawaler, Steven D; Kjeldsen, Hans; Lissauer, Jack J; Lopez, Eric D; Lund, Mikkel N; Lundkvist, Mia; Metcalfe, Travis S; Miglio, Andrea; Rogers, Leslie A; Stello, Dennis; Borucki, William J; Bryson, Steve; Christiansen, Jessie L; Cochran, William D; Geary, John C; Gilliland, Ronald L; Haas, Michael R; Hall, Jennifer; Howard, Andrew W; Jenkins, Jon M; Klaus, Todd; Koch, David G; Latham, David W; MacQueen, Phillip J; Sasselov, Dimitar; Steffen, Jason H; Twicken, Joseph D; Winn, Joshua N

    2012-08-01

    In the solar system, the planets' compositions vary with orbital distance, with rocky planets in close orbits and lower-density gas giants in wider orbits. The detection of close-in giant planets around other stars was the first clue that this pattern is not universal and that planets' orbits can change substantially after their formation. Here, we report another violation of the orbit-composition pattern: two planets orbiting the same star with orbital distances differing by only 10% and densities differing by a factor of 8. One planet is likely a rocky "super-Earth," whereas the other is more akin to Neptune. These planets are 20 times more closely spaced and have a larger density contrast than any adjacent pair of planets in the solar system. PMID:22722249

  10. Giant Coulomb blockade magnetoresistance

    SciTech Connect

    Zhang, Xiaoguang; Wen, Z. C.; Wei, H. X.; Han, Prof. X. F.

    2010-01-01

    We show that the Coulomb blockade voltage can be made to depend strongly on the electron spin in a thin magnetic granular layer inserted in the middle of an insulating layer of a tunnel junction. This strong spin dependence is predicted from the spin-dependent inter-granular conductance through any of the following effects within the granular layer, giant magnetoresistance (GMR), tunneling magnetoresistance (TMR), colossal magnetoresistance (CMR), or GMR through a polymer spacer. The resulting Coulomb blockade magnetoresistance (CBMR) ratio can exceed the magnetoresistance ratio of the granular layer itself by orders of magnitude. Unlike other magenetoresistance effects, the CBMR effect does not require magnetic electrodes.

  11. Giant Cardiac Cavernous Hemangioma.

    PubMed

    Unger, Eric; Costic, Joseph; Laub, Glenn

    2015-07-01

    We report the case of an asymptomatic giant cardiac cavernous hemangioma in a 71-year-old man. The intracardiac mass was discovered incidentally during surveillance for his prostate cancer; however, the patient initially declined intervention. On presentation to our institution 7 years later, the lesion had enlarged significantly, and the patient consented to excision. At surgery, an 8 × 6.5 × 4.8 cm intracardiac mass located on the inferior heart border was excised with an intact capsule through a median sternotomy approach. The patient had an uneventful postoperative course. We discuss the diagnostic workup, treatment, and characteristics of this rare cardiac tumor. PMID:26140782

  12. Calculation of the energy loss for an electron passing near giant fullerenes

    NASA Astrophysics Data System (ADS)

    Henrard, L.; Lambin, Ph

    1996-11-01

    We present a theoretical analysis of the electron energy-loss spectra of isolated giant fullerenes. We use a macroscopic dielectric description of spherical onion-like fullerenes and a discrete dipole approximation (DDA) framework for tubular fullerenes. In the DDA model, an anisotropic dynamical polarizability is assigned to each carbon site. We stress the fundamental importance of the hollow character of giant fullerenes in the electron energy-loss resonances.

  13. Fluid-fluid levels in giant cell tumors of bone: report of two cases.

    PubMed

    Kaplan, P A; Murphey, M; Greenway, G; Resnick, D; Sartoris, D J; Harms, S

    1987-04-01

    Fluid-fluid levels have been described in association with aneurysmal bone cysts, telangiectatic osteosarcoma, and a chondroblastoma. We report two cases of giant cell tumors of bone with fluid-fluid levels identified by computed tomography and, in one case, by magnetic resonance imaging. This finding has not previously been associated with giant cell tumors. The radiographic features of the fluid-fluid levels cannot be distinguished from those reported in other osseous neoplasms. PMID:3581850

  14. Giant cell tumor of the flexor tendon of the wrist: US and MRI evaluation. Case report

    PubMed Central

    Bassetti, E.; Candreva, R.; Santucci, E.

    2011-01-01

    Giant cell tumor of the tendon sheath (GCTTS) is a benign proliferative lesion of synovial origin that may affect the joints, bursae and tendon sheaths. We report the case of a giant cell tumor of the tendon sheath arising from the carpal tunnel of the wrist in a 47-year-old woman. The patient underwent ultrasound (US) examination and subsequently magnetic resonance imaging (MRI). PMID:23396659

  15. MERGING CRITERIA FOR GIANT IMPACTS OF PROTOPLANETS

    SciTech Connect

    Genda, H.; Kokubo, E.; Ida, S.

    2012-01-10

    At the final stage of terrestrial planet formation, known as the giant impact stage, a few tens of Mars-sized protoplanets collide with one another to form terrestrial planets. Almost all previous studies on the orbital and accretional evolution of protoplanets in this stage have been based on the assumption of perfect accretion, where two colliding protoplanets always merge. However, recent impact simulations have shown that collisions among protoplanets are not always merging events, that is, two colliding protoplanets sometimes move apart after the collision (hit-and-run collision). As a first step toward studying the effects of such imperfect accretion of protoplanets on terrestrial planet formation, we investigated the merging criteria for collisions of rocky protoplanets. Using the smoothed particle hydrodynamic method, we performed more than 1000 simulations of giant impacts with various parameter sets, such as the mass ratio of protoplanets, {gamma}, the total mass of two protoplanets, M{sub T}, the impact angle, {theta}, and the impact velocity, v{sub imp}. We investigated the critical impact velocity, v{sub cr}, at the transition between merging and hit-and-run collisions. We found that the normalized critical impact velocity, v{sub cr}/v{sub esc}, depends on {gamma} and {theta}, but does not depend on M{sub T}, where v{sub esc} is the two-body escape velocity. We derived a simple formula for v{sub cr}/v{sub esc} as a function of {gamma} and {theta} (Equation (16)), and applied it to the giant impact events obtained by N-body calculations in the previous studies. We found that 40% of these events should not be merging events.

  16. Warner Prize Lecture: A New View on Planetary Orbital Dynamics

    NASA Astrophysics Data System (ADS)

    Ford, Eric B.

    2013-01-01

    Prior to the discovery of exoplanets, astronomers fine tuned theories of planet formation to explain detailed properties of the solar system. Doppler planet searches revealed that many giant planets orbit close to their host star or in highly eccentric orbits. These and subsequent observations inspired new theories of planet formation that invoke strong mutual gravitation interactions in multiple planet systems to explain the excitation of orbital eccentricities and even short-period giant planets. NASA's Kepler mission has identified over 300 systems with multiple transiting planet candidates, including many potentially rocky planets. Most of these systems include multiple planets with sizes between Earth and Neptune and closely-spaced orbits. These systems represent another new and unexpected class of planetary systems and provide an opportunity to test the theories developed to explain the properties of giant exoplanets. I will describe how transit timing observations by Kepler are characterizing the gravitational effects of mutual planetary perturbations for hundreds of planets and providing precise (but complex) constraints on planetary masses, densities and orbits, even for planetary systems with faint host stars. I will discuss early efforts to translate these observations into new constraints on the formation and orbital evolution of planetary systems with low-mass planets.

  17. Orbital stability analysis and chaotic dynamics of exoplanets in multi-stellar systems

    NASA Astrophysics Data System (ADS)

    Satyal, Suman

    -aperiodic orbits. The stability of the system is defined in terms of its lifetime and maximum eccentricity during the integration period then a regime is established for the known and injected planet's orbital parameters. The de-stabilizing resonances due to the outer planet extend by 1.36 AU towards the star, nonetheless, existence of two Earth-mass planets seems plausible. The radial velocity (RV) curves generated for the test planets reveals a weak RV signal that cannot be measured by currently available instruments. A theory has been developed by extrapolating the radio emission processes in the Jupiter-Io system, which could reveal the presence of exomoons around the giant exoplanets. Based on this theory, maximum distance, radius and masses of exoplanets and exomoons are calculated that could be detected by the available radio telescopes. Observation time at the Low Frequency Array (LOFAR) radio telescope has been proposed to detect exomoon in five different stellar systems. Subjects of my future studies include analysis of the data from LOFAR, search for the additional transiting planets in Kepler 47 circumbinary system and observation at the Subaru telescope to verify the predicted planets in GJ 832 system by the method of direct imaging.

  18. Orbit analysis

    SciTech Connect

    Michelotti, L.

    1995-01-01

    The past fifteen years have witnessed a remarkable development of methods for analyzing single particle orbit dynamics in accelerators. Unlike their more classic counterparts, which act upon differential equations, these methods proceed by manipulating Poincare maps directly. This attribute makes them well matched for studying accelerators whose physics is most naturally modelled in terms of maps, an observation that has been championed most vigorously by Forest. In the following sections the author sketchs a little background, explains some of the physics underlying these techniques, and discusses the best computing strategy for implementing them in conjunction with modeling accelerators.

  19. Rheology of giant micelles

    NASA Astrophysics Data System (ADS)

    Cates, M. E.; Fielding, S. M.

    2006-12-01

    Giant micelles are elongated, polymer-like objects created by the self-assembly of amphiphilic molecules (such as detergents) in solution. Giant micelles are typically flexible, and can become highly entangled even at modest concentrations. The resulting viscoelastic solutions show fascinating flow behaviour (rheology) which we address theoretically in this article at two levels. First, we summarize advances in understanding linear viscoelastic spectra and steady-state nonlinear flows, based on microscopic constitutive models that combine the physics of polymer entanglement with the reversible kinetics of self-assembly. Such models were first introduced two decades ago, and since then have been shown to explain robustly several distinctive features of the rheology in the strongly entangled regime, including extreme shear thinning. We then turn to more complex rheological phenomena, particularly involving spatial heterogeneity, spontaneous oscillation, instability and chaos. Recent understanding of these complex flows is based largely on grossly simplified models which capture in outline just a few pertinent microscopic features, such as coupling between stresses and other order parameters such as concentration. The role of ‘structural memory’ (the dependence of structural parameters such as the micellar length distribution on the flow history) in explaining these highly nonlinear phenomena is addressed. Structural memory also plays an intriguing role in the little-understood shear thickening regime, which occurs in a concentration regime close to but below the onset of strong entanglement, and which is marked by a shear-induced transformation from an inviscid to a gelatinous state.

  20. Giant solitary trichoepithelioma

    PubMed Central

    Teli, Bhavuray; Thrishuli, P. B.; Santhosh, R.; Amar, D. N.; Rajpurohit, Shravan

    2015-01-01

    Adnexal tumors like giant solitary trichoepitheliomas are uncommon to most of us to permit a ready familiarity with them. Information regarding the genesis, clinical profile, behavior, and management options for this tumor is limited. There are 18 cases reported in the world literature till date. This review attempts to provide insight to this rare tumor. Our search included indexed literature from Pubmed, Directory of Open Access Journals, Health Inter Network Access to Research Initiative and Google databases in addition to standard dermatology texts. Giant solitary trichoepithelioma is a rare trichogenic tumor with potential for local recurrence. It has predilection for the older age, but may present at any age including at birth. It has close resemblance to basal cell carcinoma and other skin adnexal tumors - clinically, cytologically, and histologically. CD10, CD 34, PHLDA1 but not p75NTR are useful adjunct markers. Surgical excision is the standard treatment. Recurrence and possible transformation into BCC cautions follow up at regular intervals. PMID:25839021