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The EUV Spectrum of Sunspot Plumes Observed by SUMER on SOHO
Dwivedi, B. N.; Curdt, W.; Feldman, U.
We present results from sunspot observations obtained by SUMER on SOHO. In sunspot plumes the EUV spectrum differs from the quiet Sun; continua are observed with different slopes and intensities; emission lines from molecular hydrogen and many unidentified species indicate unique plasma conditions above sunspots. Sunspot plumes are sites of system…
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…
Electron Density and Temperature Measurements, and Abundance Anomalies in the Solar Atmosphere
Landi, Enrico; Dwivedi, Bhola N.; Mohan, Anita
Using spectra obtained from the SUMER (Solar Ultraviolet Measurements of Emitted Radiation) spectrograph on the spacecraft SOHO (Solar and Heliospheric Observatory), we investigate the height dependence of electron density, temperature and abundance anomalies in the solar atmosphere. In particular, we present the behaviour of the solar FIP effect …
Ulysses Observations of Nonlinear Wave-wave Interactions in the Source Regions of Type III Solar Radio Bursts
MacDowall, R. J.; Thejappa, G.
The Ulysses Unified Radio and Plasma Wave Experiment (URAP) has observed Langmuir, ion-acoustic and associated solar type III radio emissions in the interplanetary medium. Bursts of 50–300 Hz (in the spacecraft frame) electric field signals, corresponding to long-wavelength ion-acoustic waves are often observed coincident in time with the most int…