Lyman alpha line shapes from electron impact H2 dissociative processes in the Jovian auroral zone

Over the past two years several Lyman alpha line profile spectra of Jupiter were obtained using the International Ultraviolet Explorer (IUE) telescope. Several different regions of the planet were observed including the auroral zone, the low and mid latitudes, and the equatorial region which includes the Lyman alpha bulge region. These results have presented a very interesting picture of atomic hydrogen on Jupiter with explanations that range from ion outflow in the auroral zone to large thermospheric winds at low and mid latitudes. New data are needed to address the outstanding questions. Almost certainly, high resolution spectra from the Hubble Space Telescope will play a role in new observations. Better data also require better models, and better models require new laboratory data as inputs. The purpose of this program is two-fold: (1) to introduce a method by which new laboratory electron impact measurements of H2 dissociation can be used to calculate both the slow and fast H(S-2) and H(P-2) fragments in an H2 atmosphere; and (2) to determine the predicted Lyman alpha line shape that would result from electron impact production of these dissociative fragments in the Jovian auroral zone

Beliefs about whether spending implies wealth

Spending is influenced by many factors. One that has received little attention is the meaning that people give to the act of spending. Spending money might imply that someone is relatively wealthy—since they have money to spend—or relatively poor—since spending can deplete assets. We show that people differ in the extent to which they believe that spending implies wealth (SIW beliefs). We develop a scale to measure these beliefs and find that people who more strongly believe that SIW spend their own money relatively lavishly and are, on average, more financially vulnerable. We find correlational evidence for these relationships using objective financial-transaction data, including over 2 million transaction records from the bank accounts of over 2,000 users of a money management app, as well as self-reported financial well-being. We also find experimental evidence by manipulating SIW beliefs and observing causal effects on spending intentions. These results show how underlying beliefs about the link between spending and wealth play a role in consumption decisions, and point to beliefs about the meaning of spending as a fruitful direction for further research

Chandra Observation of an X-ray Flare at Saturn: Evidence for Direct Solar Control on Saturn's Disk X-ray Emissions

Saturn was observed by Chandra ACIS-S on 20 and 26-27 January 2004 for one full Saturn rotation (10.7 hr) at each epoch. We report here the first observation of an X-ray flare from Saturn's non-auroral (low-latitude) disk, which is seen in direct response to an M6-class flare emanating from a sunspot that was clearly visible from both Saturn and Earth. Saturn's disk X-ray emissions are found to be variable on time scales of hours to weeks to months, and correlated with solar F10.7 cm flux. Unlike Jupiter, X-rays from Saturn's polar (auroral) region have characteristics similar to those from its disk. This report, combined with earlier studies, establishes that disk X-ray emissions of the giant planets Saturn and Jupiter are directly regulated by processes happening on the Sun. We suggest that these emissions could be monitored to study X-ray flaring from solar active regions when they are on the far side and not visible to Near-Earth space weather satellites.Comment: Total 12 pages including 4 figure

Processes of equatorial thermal structure at Jupiter: An analysis of the Galileo temperature profile with a three‐dimensional model

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94956/1/jgre1925.pd

Ultraviolet observations of the Saturnian north aurora and polar haze distribution with the HST-FOC

Near simultaneous observations of the Saturnian H2 north ultraviolet aurora and the polar haze were made at 153 nm and 210 nm respectively with the Faint Object Camera on board the Hubble Space Telescope. The auroral observations cover a complete rotation of the planet and, when co-added, reveal the presence of an auroral emission near 80 deg N with a peak brightness of about 150 kR of total H2 emission. The maximum optical depth of the polar haze layer is found to be located approximately 5 deg equatorward of the auroral emission zone. The haze particles are presumably formed by hydrocarbon aerosols initiated by H2+ auroral production. In this case, the observed haze optical depth requires an efficiency of aerosol formation of about 6 percent, indicating that auroral production of hydrocarbon aerosols is a viable source of high-latitude haze

Processes of Equatorial Thermal Structure: An Analysis of Galileo Temperature Profile with 3-D Model

The Jupiter Thermosphere General Circulation Model (JTGCM) calculates the global dynamical structure of Jupiter's thermosphere self-consistently with its global thermal structure and composition. The main heat source that drives the thermospheric flow is high-latitude Joule heating. A secondary source of heating is the auroral process of particle precipitation. Global simulations of Jovian thermospheric dynamics indicate strong neutral outflows from the auroral ovals with velocities up to approximately 2 kilometers per second and subsequent convergence and downwelling at the Jovian equator. Such circulation is shown to be an important process for transporting significant amounts of auroral energy to equatorial latitudes and for regulating the global heat budget in a manner consistent with the high thermospheric temperatures observed by the Galileo probe. Adiabatic compression of the neutral atmosphere resulting from downward motion is an important source of equatorial heating (less than 0.06 microbar). The adiabatic heating continues to dominate between 0.06 and 0.2 microbar, but with an addition of comparable heating due to horizontal advection induced by the meridional flow. Thermal conduction plays an important role in transporting heat down to lower altitudes (greater than 0.2microbar) where it is balanced by the cooling associated with the wind transport processes. Interestingly, we find that radiative cooling caused by H3(+), CH4, and C2H2 emissions does not play a significant role in interpreting the Galileo temperature profile

Order parameter of MgB_2: a fully gapped superconductor

We have measured the low-temperature specific heat C(T) for polycrystalline MgB_2 prepared by high pressure synthesis. C(T) below 10 K vanishes exponentially, which unambiguously indicates a fully opened superconducting energy gap. However, this gap is found to be too small to account for Tc of MgB_2. Together with the small specific heat jump DeltaC/gamma_nTc=1.13, scenarios like anisotropic s-wave or multi-component order parameter are called for. The magnetic field dependence of gamma(H) is neither linear for a fully gapped s-wave superconductor nor H^1/2 for nodal order parameter. It seems that this intriguing behavior of gamma(H) is associated with the intrinsic electronic properties other than flux pinning.Comment: 7 pages, 5 figures; revised text and figures; references updated, Phys. Rev. Lett., in pres

X‐ray emission from the outer planets: Albedo for scattering and fluorescence of solar X rays

Soft X‐ray emission has been observed from the low‐latitude "disk" of both Jupiter and Saturn as well as from the auroral regions of these planets. The disk emission as observed by ROSAT, the Chandra X‐Ray Observatory, and XMM‐Newton appears to be uniformly distributed across the disk and to be correlated with solar activity. These characteristics suggest that the disk X rays are produced by (1) the elastic scattering of solar X rays by atmospheric neutrals and (2) the absorption of solar X rays in the carbon K‐shell followed by fluorescent emission. The carbon atoms are found in methane molecules located below the homopause. In this paper we present the results of calculations of the scattering albedo for soft X rays. We also show the calculated X‐ray intensity for a range of atmospheric abundances for Jupiter and Saturn and for a number of solar irradiance spectra. The model calculations are compared with recent X‐ray observations of Jupiter and Saturn. We conclude that the emission of soft X rays from the disks of Jupiter and Saturn can be largely explained by the scattering and fluorescence of solar soft X rays. We suggest that measured X‐ray intensities from the disk regions of Jupiter and Saturn can be used to constrain both the absolute intensity and the spectrum of solar X rays