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Convective high-speed flow and field-aligned high-speed flows explored by TC-1
Dunlop, M. W.; Baumjohann, W.; Carr, C. +6 more
From June 1, 2004 to October 31, 2006, a total 465 high-speed flow events are observed by the TC-1 satellite in the near-Earth region (-13 RE < x < -9 RE, |Y|<10 RE, |Z|<5 RE). Based on the angle between the flow and the magnetic field, the high-speed flow events are further divided into two types, that is, field-aligned high-speed flo…
Thread safe astronomy
Seaman, R.
Observational astronomy is the beneficiary of an ancient chain of apprenticeship. Kepler's laws required Tycho's data. As the pace of discoveries has increased over the centuries, so has the cadence of tutelage (literally, "watching over"). Naked eye astronomy is thousands of years old, the telescope hundreds, digital imaging a few decades, but to…
Geometrical Structure Analysis of the Magnetic Field
Shen, Chao; Dunlop, Malcolm W.
The geometrical configuration of the magnetic field underpins important research top- ics in magnetospheric physics. The magnetic field is the skeleton of the magnetosphere and plays a crucial role in determining the plasma distribution of particles, the occurrences of various macro and micro instabilities, the triggering and evolution of substorm…
Emission stratification in two-component HII regions with stellar wind
Sitnik, T. G.; Bychkov, K. V.
To explain the variety of observed optical emission stratification in the shells around Wolf-Rayet stars, we have calculated the nonstationary cooling of a homogeneous gas layer heated to a temperature (0.4-2) × 105 K. We have assumed that the nebula is ionized by its central star and consists of a rarefied gas and a set of clouds with …
Identification of spacecraft conjunctions in the cusps
Stubbs, T. J.; Keith, W. R.
The comparison of particle energy distributions from different altitudes in the cusp is important for developing our understanding of magnetospheric entry and energization processes. The Cluster multi-spacecraft mission allows the opportunity to better understand the features at higher altitudes, facilitating direct comparisons with concurrent low…
The Central Component of Gravitational Lens Q0957+561
Winn, Joshua N.; Haarsma, Deborah B.; Shapiro, Irwin +1 more
In 1981, a faint radio source (G') was detected near the center of the lensing galaxy of the famous "twin quasar" Q0957+561. It is still unknown whether this central radio source is a third quasar image or an active nucleus of the lensing galaxy, or a combination of both. In an attempt to resolve this ambiguity, we observed Q0957+561 at radio wave…
Bolometric correction of the roAp star αCir
Brandão, I. M.; Cunha, M. S.; Gameiro, J. F.
For the first time, the bolometric correction of α Cir was determined. Two values, both based on an estimation of the total integrated flux, were obtained. For that purpose spectroscopic and photometric data of α Cir available in the literature was used. The values derived were then used to place α Cir in the HR diagram.
Using Weak-Lensing Dilution to Measure Light Properties of A1689
Broadhurst, Tom; Coe, Dan; Umetsu, Keiichi +1 more
Weak-lensing induced by clusters of galaxies can probe the total mass distribution out to the virial radius of the cluster, regardless of the nature of the mass or its dynamical state. To make a robust analysis, the cluster and background galaxy populations need to be separated. The E/S0 sequence of a cluster defines a boundary redward of which a …
Mars Express/ASPERA-3/NPI and IMAGE/LENA observations of energetic neutral atoms in Earth and Mars orbit
Barabash, S.; Holmström, M.; Brinkfeldt, K. +3 more
The low energy neutral atom imagers on Mars Express and IMAGE have revealed that the neutral atom populations in interplanetary space come from a variety of sources and challenge our current understanding of heliospheric physics. For example, both in cruise phase and at Mars, the neutral particle instrument NPD on Mars Express observed “unexplaine…
Time-Resolved FUSE Spectroscopy of the LMC WC + O Binaries Br 22 and Br 32
Moffat, Anthony F. J.; St-Louis, Nicole; Marchenko, Sergey V. +1 more
Using the Far Ultraviolet Spectroscopic Explorer satellite, we obtained series of spectra for two of the three known WC + O binaries in the LMC, Br 22, and Br 32 (HD 36521). Compared to Br 22, we detect a higher ratio of C IV to He II lines in Br 32, which could indicate a more advanced evolutionary stage for the latter. The orbit of the O star in…