Search Publications
Modulation of Proton Fluxes at ~5 AU during the Largest SEP Events of 2005
Heber, Bernd; Klassen, Andreas; Struminsky, Alexei +1 more
The Ulysses spacecraft was close to the ecliptic at ~5 AU during the periods of enhanced solar activity in January and September 2005. The KET/Ulysses instrument registers a flux of cosmic ray protons within 5-2000 MeV, fluxes have been disturbed more than three solar rotations during the considered period. We find two periods of 27 days, when dis…
Very Large Array, SOHO, and RHESSI Observations of Magnetic Interactions and Particle Propagation across Large-Scale Coronal Loops
Groff, Tyler D.; Willson, Robert F.
Very Large Array (VLA) observations at wavelengths of 20 and 91 cm have been combined with data from the SOHO and RHESSI solar missions to study the evolution of transequatorial loops connecting active regions on the solar surface. The radio observations provide information about the acceleration and propagation of energetic electrons in these lar…
Spectral Analysis of LMC-X2 with XMM/Newton
Robba, N. R.; Iaria, R.; di Salvo, T. +2 more
We present the results of the analisys of an archival observation of LMC X-2 performed with XMM/Newton. The spectra of this source has never been analyzed with a high precision instrument before. The spectrum of the source can be fitted with a blackbody with a temperature 1.5 keV plus a disk blackbody at 0.8 keV. We argue that the emission of this…
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.