Search Publications

Hard X-rays from the galactic nucleus: present and future observations

Goldoni, P.; Laurent, P.; Lebrun, F. +2 more

In spite of increasing evidences of the presence of a massive Black Hole at the Galactic Center, its radio counterpart, Sgr A*, shows little activity at high energies, and recent models involving energy advection (ADAF) have been proposed to explain this difficulty. We present results on the hard X-ray emission from the galactic central square deg…

Supernova Theory

Lattimer, J. M.

Supernova theory relies heavily upon the underlying equation of state (EOS). The role of the EOS during stellar collapse, and recent attempts to delineate the EOS from astrophysical observations, are discussed

Relationship between X-ray and ultraviolet emission in 3C 273

Paltani, S.; Walter, R.; Courvoisier, T. J. -L. +1 more

In 3C 273, ultraviolet flux and X-ray flux measured by BATSE are not well correlated, contrarily to predictions of several models, unless the X-ray flux lags the UV emission by 1.75 yr. The absence of observed correlation at small lag cannot be due to spectral variability. A Comptonizing corona model is however compatible with all UV and X-ray obs…

Ulysses/BeppoSAX observations of cosmic gamma-ray bursts

Piro, L.; Frontera, F.; Orlandini, M. +5 more

BeppoSAX has been added to the 3rd Interplanetary Network of gamma-ray burst detectors. Of the 8 events observed to date by Ulysses and the BeppoSAX Gamma Ray Burst Monitor (GRBM), four have been localized by triangulation, resulting in annuli whose 3σ widths are as small as 63''. These data give error boxes whose sizes are sometimes smaller than …

Specialized detector techniques and electronics of the ERNE instrument onboard SOHO

Valtonen, E.; Peltonen, J.; Eronen, T. +5 more

ERNE is designed to study the composition and energy spectra of particles encountered in interplanetary space in the energy range from 1 MeV/n to well beyond 500 MeV/n. Several innovative ideas had to be incorporated in the design of the instrument in order to fulfill the scientific requirements. Position-sensitive strip detectors are used in the …

High Energy Cosmic Ray Results from the ULYSSES Ascent to the Solar South Pole

Sierks, H.; Kunow, H.; Wibberenz, G. +9 more

Energetic particle observations in high heliographic latitudes

Krupp, N.; Fränz, M.; Keppler, E. +1 more

Magnetic fields in the high latitude heliosphere

Balogh, A.

Energetic particle results from ulysses (extended abstract)

Sierks, H.; Kunow, H.; Wibberenz, G. +6 more

COS-B: The highlights

Bennett, Kevin

The COS-B satellite operated from August 1975 until April 1982 during which time an extensive survey of the Galaxy was made in the energy range 50 MeV to 5 Gev. The Caravane Collaboration built the gamma-ray telescope and performed the bulk of the scientific data reduction. Since the data are now available to the Astrophysics community at large, s…