Search Publications
Quiet time MEV electron increases at solar maximum: Ulysses cospin/ket observations
Fichtner, H.; Kunow, H.; Wibberenz, G. +10 more
The Ulysses trajectory provides a unique opportunity to study the propagation of MeV electrons in a wide range of heliographic latitudes and during varying conditions in the inner heliosphere. In recent papers we reported Ulysses Kiel Electron Telescope (KET) observations from the Ulysses launch up to the end of the second fast latitude scan in la…
Continuous tracking of CMEs using MICA, and LASCO C2 and C3 coronagraphs
Schwenn, R.; Stenborg, G.; Balmaceda, L. +3 more
In this work we have tracked coronal mass ejections observed with the ground based Mirror Coronagraph for Argentina (MICA) and the Large Angle and Spectroscopic Coronagraph (LASCO) C2 and C3 on board of the Solar and Heliospheric Observatory (SOHO). The MICA telescope is located at El Leoncito (31.8 S, 69.3 W), San Juan (Argentina), since 1997 as …
Coronal loops: Isothermal OR multithermal?
Schmelz, J. T.; Cirtain, J. W.; Beene, J. E. +5 more
Are coronal loops isothermal? A controversy over this question has arisen recently because different investigators using different techniques have obtained very different answers. Analysis of data using narrowband filter ratios to obtain temperature maps has produced several key publications that suggest that coronal loops may be isothermal. We ha…
Coronal densities and temperatures for cool stars in different stages of activity
Schmitt, J. H. M. M.; Audard, M.; Güdel, M. +1 more
With the advent of the new X-ray missions Chandra and XMM-Newton, high-resolution spectroscopy has become available for studies of stellar coronae. Individual lines can be used as diagnostic tools for measuring densities and temperatures in coronal plasma. In addition to the overall X-ray luminosity, spectroscopic properties can be used for a clas…
Peak proton intensities and composition variations of heavy ions during large solar energetic particle events: Uleis observations
Gold, R. E.; Roelof, E. C.; Ho, G. C. +2 more
We have examined low energy proton and heavy ion intensities in large solar energetic particle (SEP) events from 1997 to the end of 2001 using the ULEIS instrument on ACE spacecraft. We selected 33 events that are isolated and show clear onsets at 1 AU. The optical and radio signatures for all of our events are identified and where data are availa…
Experimental studies of wave-particle interactions in space using particle correlators: Results and future developments
Gough, M. P.; Buckley, A. M.; Carozzi, T. +1 more
The technique of particle correlation measures directly electron modulations that result from naturally occurring and actively stimulated wave-particle interactions in space plasmas. In the past this technique has been used for studies of beam-plasma interactions, caused by both natural auroral electron beams via sounding rockets and by artificial…
High order spectral analysis of electron plasma oscillations in the electron foreshock
Gurnett, D. A.; Pickett, J. S.; Walker, S. N. +1 more
The electron foreshock is the region in which electrons that have been reflected from the shock propagate back upstream along the magnetic field lines forming electron beams. The process of relaxation of these beams is one of the fundamental topics in plasma physics. It involves numerous nonlinear processes. High order spectral analysis is applied…
Solar radio observations and development of coronal mass ejections
Pick, M.; Maia, D.; Marqué, Ch.
We present in this study a synthesis of results on the initiation and development of CMEs using coordinated observations from SOHO and ground-based instruments. The emphasis is placed on radio spectral and imaging data. One important goal of this study is the identification of radio signatures of CMEs providing information below one solar radius a…
Pile-up on X-ray CCD instruments
Ballet, J.
Pile-up occurs on X-ray CCDs when several photons hit the detector at the same place between two readouts. In that case they are counted as one (or not at all) and their energies are summed. Pile-up thus affects both flux measurements and spectral characterisation of bright sources. Here I extend a previous work on flux loss, and present a simple …
Comparative study of the dust emission of 19P/Borrelly (Deep space 1) and 1P/Halley
Soderblom, L. A.; Thomas, N.; Ho, T. M. +2 more
Images obtained by the Miniature Integrated Camera and Imaging Spectrometer (MICAS) experiment onboard the Deep Space 1 spacecraft which encountered comet 19P/Borrelly on September 22nd 2001 show a dust coma dominated by jets. In particular a major collimated dust jet on the sunward side of the nucleus was observed. Our approach to analyse these f…