Search Publications
Initial Results from the XUV Doppler Telescope
Kano, R.; Kobayashi, K.; Tsuneta, S. +6 more
We developed a unique telescope to obtain simultaneous XUV images and the velocity maps by measuring the line-of-sight Doppler shifts of the Fe XIV 211A&ring line (T = 1.8 MK): the Solar XUV Doppler Telescope (hereafter XDT). The telescope was launched by the Institute of Space and Astronautical Science with the 22nd S520 rocket on January 31,…
Coupling of the high and low latitude heliosphere and its relation to the corona. Proceedings. D0.7 Symposium of COSPAR Scientific Commission D held during 32nd COSPAR Scientific Assembly, Nagoya (Japan), 12 - 19 Jul 1998.
Kunow, H.
The following topics were dealt with: solar wind acceleration, interplanetary scintillation measurements, solar wind structure, solar wind acceleration region, 3D MHD simulations of coronal mass ejections, interplanetary magnetic clouds, coronal streamers, plasma velocity in interplanetary magnetic structures, H cell measurements, polar plume and …
Deep Survey Sources, and Predictions for XMM and AXAF
Ptak, A.; Georgantopoulos, I.; Griffiths, R. E. +6 more
From the deep surveys performed with the ROSAT and ASCA X-ray observatories, we have now built up a plausible picture of the constitution of the X-ray background and the way in which AGNs (and starburst nuclei surrounding AGNs) account for it. But major problems remain: the best model that we have is one in which the XRB above 3 kev is accounted f…
Corotating interaction regions
Heber, B.; Zhang, M.; Sanderson, T. R.
Corotating Interaction Regions are long lasting large-scale plasma structures generated in low and middle latitude regions of the heliosphere by the interaction of a stable fast solar wind stream with the surrounding slow solar wind. Associated with these plasma structures are recurrent MeV-ion events and recurrent decreases of the galactic and an…
Variations in total solar and spectral irradiance as measured by the VIRGO experiment on SOHO
Fröhlich, Claus; Wehrli, Christoph; Pap, Judit +3 more
The Variability IRradiance Gravity Oscillation (VIRGO) experiment on SOHO has been observing total solar and spectral irradiances at 402 nm (blue channel), 500 nm (green channel), and 862 nm (red channel) since January 1996. The VIRGO observations have shown that solar active regions influence both total and spectral irradiances in a similar fashi…
On the gradients of ACR oxygen at intermediate heliocentric distances: Ulysses/Soho results
Torsti, J.; Sanderson, T. R.; Marsden, R. G. +3 more
During 1997 and up to the present time, the heliocentric position of the Ulysses spacecraft has changed only slowly in distance and latitude, being close to the equator at a distance of ~5 AU. This period provides an excellent opportunity to observe the evolution of the Anomalous Cosmic Ray (ACR) spectrum at a location intermediate between 1 AU an…
Implications of the heliospheric modulation of cosmic ray electrons observed by ulysses
Ferreira, S. E. S.; Potgieter, M. S.; Heber, B. +2 more
The results of a moderate drift model with anisotropic perpendicular diffusion for the heliospheric modulation of galactic cosmic rays were compared with electron spectra observed by the Kiel Electron Telescope on board the Ulysses spacecraft for four distinctive periods, 1992, 1995, 1996, and 1997, respectively, for relative large solar activity …
Latitudinal and radial variation of >2 GeV/n protons and α-particles in the northern heliosphere: ulysses cospin/ket and neutron monitor network observations
Kunow, H.; Bothmer, V.; Wibberenz, G. +10 more
Ulysses, launched in October 1990, crossed in December 1997 the heliographic equator and completed its first out of ecliptic orbit. During the time period from February 1995 to November 1997 solar activity was low and the spacecraft scanned the latitude range from 80° N to the heliographic equator. The Kiel Electron Telescope on-board Ulysses meas…
The Cassini-Huygens ACP experiment and exobiological implications
Israel, G.; Coll, P.; Raulin, F. +3 more
Since the discovery of its dense nitrogen atmosphere Titan, the largest satellite of Saturn has always been the subject of a strong interest by the scientific community of the exobiologists. The main reason is that Titan's atmosphere is believed to be over geologic time a permanent source of N- containing organic molecules (mostly nitriles) and of…
The role of stars in the energetics of LINERs
Maoz, Dan
Imaging studies have shown that ~ 25% of LINER galaxies display a compact nuclear UV source. I compare the HST ultraviolet (1150-3200 Å) spectra that are now available for seven such ``UV-bright'' LINERs. The spectra of NGC 404, NGC 4569, and NGC 5055 show clear absorption-line signatures of massive stars, indicating a stellar origin for the UV co…