Search Publications
Solar Wind Composition at Solar Maximum
Bochsler, Peter
Although coronal mass ejections have traditionally been thought to contribute only a minor fraction to the total solar particle flux, and although such events mainly occur in lower heliographic latitudes, the impressive spectacle of eruptions - observed with SOHO/LASCO even at times of solar minimum - indicates that an important part of the low-la…
A close look into an intermediate redshift galaxy using STIS
Pasquali, A.; de Mello, D. F.
We present a detailed view of a galaxy at z=0.4 which is part of a large database of intermediate redshifts using high resolution images. We used the STIS parallel images and spectra to identify the object and obtain the redshift. The high resolution STIS image (0.05'') enabled us to analyse the internal structures of this galaxy. A bar along the …
On the determination of the gamma-ray contribution in the 3-10 MeV KET electron channel along the Ulysses trajectory
Fichtner, H.; Kunow, H.; Ferreira, S. E. S. +6 more
Since the first Jovian fly-by of Pioneer 10 in 1973, it has been established that Jupiter's magnetosphere is a powerful accelerator of electrons up to several tens of MeV, which are released into interplanetary space. Measurements from Pioneer, Voyager and from spacecraft near Earth, e.g. IMP, indicate that the Jovian electron flux exceeds the gal…
The use of radar observations of Near-Earth Asteroids in the determination of the dynamical equinox
Yagudina, Eleonora I.
Near-Earth Asteroids (NEAs) are Solar system special class objects attracting the attention of astronomical community especially during several of the last decades. To some extent the NEAs have an advantage over the minor planets of the main belt: due to close and regular approaches to the Earth the radar observations of NEAs can be obtained for t…
Radial and latitudinal intensity gradients of galactic and anomalous cosmic rays in the outer heliosphere
McDonald, F. B.; Fujii, Z.
The basic one~@~Sdimensional transport model gives the equation, gr=CVSW/~Zrr where C is the Compton-Getting factor, VSW is the solar wind velocity and ~Zrr is thee radial diffusion coefficient. In the inner heliosphere near the ecliptic plane ~Zrr iss dominated by the parallel diffusion with transition to perpendicular diffusion at near 10 AU in …
Diffusive Particle Transport in Heliomagnetic Fields with Organized Latitudinal Components
Jokipii, J. R.; Kota, J.
We discuss the potential role the meridional component of the large-scale heliospheric magnetic field (HMF) might play in the transport of cosmic rays. The standard Archimedean spiral lines of the steady, large-scale HMF has no latitudinal component. Hence latitudinal transport of particles may occur only through particle drifts and cross-field di…
Search for Microflaring Activity in the Magnetic Network
Falchi, A.; Cauzzi, G.; Falciani, R.
We analyze the temporal behavior of network bright points (NBPs) searching for low-atmosphere signatures of flares occurring on the magnetic network. We make use of a set of data acquired during coordinated observations between ground-based observatories (NSO/Sacramento Peak) and the MDI instrument on board SOHO. Light curves in chromospheric spec…
UVCS Observations of Velocity Shear at Streamer Boundaries in the Corona
Habbal, Shadia Rifai; Woo, Richard; Vial, Jean-Claude
Measurements of the intensities of the Ovi 1032 and 1037 Å spectral lines in the southern solar hemisphere, from 1.5 to 5 R_s, were made with the SOHO Ultraviolet Coronagraph Spectrometer (UVCS) in May 2000 close to solar maximum. The ratio of the intensity of the two oxygen lines is used as a proxy for solar wind velocity in the inner corona. Whi…
Magnetic Field Line Transport in the Heliosphere and Energetic Particle Propagation from Corotating Interaction Regions to High Heliographic Latitudes
Zimbardo, Gaetano; Veltri, Pierluigi; Pommois, Pierre
A numerical model of magnetic turbulence allows us to compute the diffusion coefficients for different degrees of anisotropy, and in particular for the cases corresponding to the solar wind. We consider here the problem of the propagation of the energetic particles accelerated by corotating interaction regions (CIRs) and observed by Ulysses at hig…
Rigidity Dependence and Time Response of Cosmic Rays to the Modulation Steps in the Rising Part of Solar Cycle 23. Cospin/ket Results
Kunow, H.; Heber, B.; Müller-Mellin, R. +4 more
Previous work on the latitudinal gradient and on the amplitude of the recurrent cosmic ray decreases, has shown that their magnitude does not decrease monotonically with the particle rigidity, but it presents a broad maximun around 1 2 GV. We have extended this analysis to study the behaviour of cosmic-ray particles during the modulation steps in …