Search Publications
A new look at the OB associations and star clusters in the Puppis-Vela region using HIPPARCOS data
Subramaniam, Annapurni; Bhatt, H. C.
Search for X-ray flares in the Pleiades using SoHO LASCO C3 images.
Andrews, A. D.
The detection threshold on LASCO C3 images was examined using the Pleiades cluster. It was found that 100 Pleiades stars to V = 10 were easily identified, and that some stars 4 magnitudes fainter than this could be detected. The brightness of the stellar corona at X-ray wavelengths, especially of active flare stars, may be the explanation for the …
Solar Prominences Observed by Soho (SUMER, CDS, EIT) and Ground-Based Observatories (GBO)
Heinzel, P.; Schmieder, B.; Rudawy, P. +1 more
We present two sets of prominence observations in higher lines of the hydrogen Lyman series (from Lδ to L-9), together with some other UV lines. These data have been obtained by the Solar Ultraviolet Measurements of Emitted Radiation (SUMER) onboard the SOHO satellite in June 1997. Coordinated observations were also taken by other SOHO instruments…
Fe+ column density and line opacities of the UV2 multiplet of Fe bt II in laboratory and peculiar stellar sources in laboratory and peculiar stellar sources
Rossi, C.; Baratta, G. B.; Viotti, R. F. +1 more
The Self-Absorption Curve method has been applied to the UV2 multiplet a6D-z6Fo of Fe ii observed in the laboratory and in emission-line stars. For the laboratory observations line opacities of this multiplet were obtained using various sets of atomic data. The best fit is obtained using data by Bergeson et al. (19…
Search for Velocity Variations in Fe XIV 5304 A&ring Coronagraph Observations Near Activity Minimum
Howard, R. A.; Wood, B. E.; Karovska, M. +4 more
The LASCO C1 coronagraph on the SOHO satellite observes the solar corona from 1.1 to 3.0 Ro, and contains a Fabry-Perot interferometer which can image the corona in the 1.8 million K Fe XIV green line. We designed an observing program with reduced spatial coverage and reduced profile coverage at only three wavelengths to study coronal heating in o…
Stellar sources in the isogal inner galactic bulge field (l=0°,b= ‑ 1°)
Ganesh, S.; Omont, A.; Schultheis, M. +2 more
ISOGAL is a survey at 7 and 15 µm with ISOCAM of the inner galactic disk and bulge of our Galaxy. The survey covers ∼ 22 deg2 in selected areas of the centrall = ±30 degree of the inner Galaxy. In this paper, we report the study of a small ISOGAL field in the inner galactic bulge (l = 0°,b = ‑1°, area = 0.033deg2). Usin…
Nonpotential Broadening of UV Lines Observed at the Limb of the Quiet Sun
Chae, Jongchul; Yun, Hong Sik; Lee, Hyunsook
We have done a spectroscopic study of the solar transition region using high resolution UV & EUV data obtained by SUMER) on board SOHO. Optically thin and conspicuous emission lines observed at the solar limb are carefully selected to acquire average values of physical parameters for the quiet region as a function of radial distance. Our main …
Deglitching methods by the ISOPHOT Interactive Analysis (PIA)
Gabriel, C.; Acosta-Pulido, J. A.
The ISOPHOT detectors were continuously exposed to high energy cosmic particles hits, resulting in an average hit rate frequency of an event per every 7 s. The net effect is a disturbance of the readout voltages, which decreases the signal-to-noise ratio and hence the photometric accuracy level. Thanks to the highly redundant readout method of ISO…
Detection of zero anisotropy at 5.2 AU during the November 1998 solar particle event: Ulysses Anisotropy Telescopes observations
Balogh, A.; Dalla, S.
For the first time during the mission, the Anisotropy Telescopes instrument on board the Ulysses spacecraft measured constant zero anisotropy of protons in the 1.3-2.2 MeV energy range, for a period lasting more than three days. This measurement was made during the energetic particle event taking place at Ulysses between 25 November and 15 Decembe…
Structure and Dynamics in the Atmosphere Above Sunspot Regions
Kjeldseth-Moe, O.; Haugan, S. V. H.; Brekke, P. +3 more
Based on simultaneous observations of 10 EUV emission lines with the Coronal Diagnostic Spectrometer - CDS on the Solar and Heliospheric Observatory - SOHO we study the spatial distributions of both line emission and line-of-sight velocity in the atmosphere above 17 sunspots. We find that both the enhanced EUV line emissions and the velocities are…