Search Publications

Particle observations and propagation in the Three-Dimensional Heliosphere

Lario, D.; Forsyth, R. J.; Lanzerotti, L. J. +9 more

Ulysses, the first spacecraft ever to fly over the poles of the Sun, plays a central role in the Heliospheric Network, the international fleet of spacecraft to explore the Sun and Heliosphere. In November 2006, Ulysses, began its passage over the Sun’s south pole for the third time. Although like during the first polar passes in 1994/1995 the Sun …

Lecture Notes and Essays in Astrophysics.III. 3rd Symposium of the Astrophysics Group of the Spanish Royal Physical Society (RSEF).

Manteiga, M.; Ulla, A.

The Third volume of "Lecture Notes and Essays in Astrophysics" highlights some important contributions of Spanish astrophysicists to Planetology, Solar and Stellar Physics, Extragalactic Astronomy, Cosmology and astronomical instrumentation. After decades without a dedicated mission, Venus is again in fashion. On the one hand, Ricardo Hueso and co…

The ULF wave in the pile-up and dipolarization process

Liu, Zhen-Xing; Shi, Jian-Kui; Wang, Ji-Ye +3 more

A typical substorm process in the night-side near-Earth magnetotail company with the pile-up and depolarization process explored by TC-1 on sep 17, 2004. We analyzed the FGM and HIA data(4s resolution) with wavelet and FFT analysis method to understand the low-frequency wave in the pile-up and dipolarization process. The analysis results showed th…

Rapporteur Paper on the Composition of Comets

Altwegg, Kathrin

The ISSI workshop on “Origin and evolution of comet nuclei” had the goal to put together recent scientific findings concerning the “life” of a comet from the formation of the material in a dark molecular cloud to the accretion in the early solar system, from cometesimals to comet nuclei which were shaped and altered by cosmic rays, by radioisotopi…

Young star clusters in the Antennae galaxies and NGC 1487

Lehnert, M. D.; Vacca, W. D.; Chandar, R. +3 more

We estimate the dynamical masses of several young ({≈ 10} Myr) massive star clusters in two interacting galaxies, NGC 4038/4039 (``The Antennae") and NGC 1487, under the assumption of virial equilibrium. These are compared with photometric mass estimates. A dynamical mass substantially higher than the photometric estimate could indicate non-virial…

Global Effects of Local Sound-Speed Perturbations in the Sun: A Theoretical Study

Larson, T. P.; Hanasoge, S. M.

We study the effect of localized sound-speed perturbations on global mode frequencies by applying techniques of global helioseismology to numerical simulations of the solar acoustic wave field. Extending the method of realization-noise subtraction (e.g., Hanasoge, Duvall, and Couvidat, Astrophys. J.664, 1234, 2007) to global modes and exploiting t…

Analysis of the H ⁺ ring velocity distribution function near the Martian and Venusian bow shocks by an analytical model

Kallio, E.; Yamauchi, M.; Frilund, H.

We have studied the H ⁺ velocity distribution function at Mars and Venus near the bow shock both in the solar wind and in the magnetosheath by a simple analytical one-dimensional model. We found that over half of the ions in the ring velocity distribution which moved towards the magnetosheath were scattered back into the bow shock. The …

Simulating the SMART1 orbiter impact on the Moon's surface

Bratov, V. A.; Morozov, N. F.; Petrov, Yu. V.

Could We Have Forecast "The Day the Solar Wind Died"?

McIntosh, Scott W.; Leamon, Robert J.

In 1999 May an interval of unusually slow (<300 km s^-1) and rarefied (<1 cm^-3) solar wind was observed upstream of Earth by the ACE spacecraft. The event has been dubbed "The Day the Solar Wind Died." We apply our solar wind forecast model to the interval in question, to ask whether we could have predicted the phenomeno…

The Effect of a Latitudinal Dependent Solar Wind Speed on Cosmic-Ray Modulation in a Fisk-type Heliospheric Magnetic Field

Burger, R. A.; Hitge, M.

The Fisk-model for the heliospheric magnetic field (HMF) was developed in an attempt to connect the structure of the magnetic field at large heliocentric distances to processes in and above the photosphere. A Fisk-Parker hybrid model that is valid for the whole heliosphere (Burger and Hitge 2004, ApJL, 617) and the whole solar cycle (Kruger 2006, …