Search Publications
ISOPHOT far-infrared photometry of NGC 3079
Walker, H. J.; Klaas, U.
FIR photometry (from 15 mu m to 200 mu m) of NGC 3079 which is resolved by ISOPHOT at 60 mu m is presented. With the assumption of an unresolved core plus an extended disk component, good consistency with IRAS and SCUBA data is found. The SED of the total flux between 60 mu m and the submm can be modelled by the superposition of three dust compone…
Solar and Heliospheric Observatory/Solar Ultraviolet Measurements of Estimated Radiation ultraviolet array detector distortion correction
Moran, Thomas G.
We present the technique used to correct the geometric distortion in the Solar and Heliospheric Observatory/Solar Ultraviolet Measurement of Estimated Radiation (SOHO/SUMER) ultraviolet spectrograph images. Electric and magnetic fields within the SUMER crossed delay line detectors and optical misalignment within the SUMER spectrograph cause focal …
UV line intensity and flow velocity distributions in two coronal mass ejections as deduced by UVCS-SOHO observations
Uzzo, M.; Spadaro, D.; Ventura, R. +1 more
The Ultraviolet Coronagraph Spectrometer (UVCS) instrument onboard the SOHO satellite observed two coronal mass ejections on November 2 and 3, 2000, related to the eruptions of a large filament structure in an active region close to the West limb of the Sun, and of a prominence near the South Pole, respectively. Intensity and profile of the O VI r…
Analysis of archival EXOSAT data on the X-ray burst source Serpens X-1
Min, K. W.; Seon, K. -I.
We present analysis of data obtained from the Medium Energy proportional counter array (ME) from the EXOSAT observations of the X-ray burst source Ser X-1 made in 1983 and 1985. From the combined analysis of the spectral and fast variability properties, we show that the source is an atoll source in the banana state during the observations. The per…
The origin of the radio emission from beta Lyrae
Umana, G.; Leone, F.; Trigilio, C.
In this paper we present new observational evidence that supports the presence of an extra source of continuum emission in the binary system
An Introduction to the Design of the Cassini Spacecraft
Henry, Curt A.
In October of 1997 NASA launched its largest interplanetary spacecraft to date. The Cassini spacecraft will arrive at Saturn in July of 2004 and begin a four year tour of that planetary system. After the spacecraft arrives it will separate into an orbiter and a probe. The Huygens Probe, developed by the European Space Agency, will follow a ballist…
Systematic relations between the HIPPARCOS catalogue and major (fundamental) catalogues of the 20th century (Paper II)
Schwan, H.
Presented are the systematic relations between the HIPPARCOS catalogue and major catalogues of the 20th century, not yet treated in Paper I. Colour-dependent errors in the catalogues are also determined and eliminated. The derived systematic relations allow one to reduce observations given in the system of one of the analyzed catalogues to the HIP…
Helioseismic limit on heavy element abundance
Antia, H. M.; Chitre, S. M.
Primary inversions of accurately measured solar oscillation frequencies coupled with the equations of thermal equilibrium and other input physics, enable us to infer the temperature and hydrogen abundance profiles inside the Sun. These profiles also help in setting constraints on the input physics as well as on heavy element abundance in the solar…
Quiet-Sun variability observed with SUMER and CDS
Solanki, S. K.; Brković, A.; Rüedi, I.
Brightness variations of solar features are investigated using time series of images and spectra of quiet-Sun regions at disc centre obtained with the Coronal Diagnostic Spectrometer (CDS) and the Solar Ultraviolet Measurements of Emitted Radiation (SUMER) instrument onboard the SOHO spacecraft. Ultraviolet emission lines sampling temperatures of …
Constraints on ion outflow speeds and electron distribution function in the corona derived from sumer electron temperatures and SWICS ion fractions
Esser, R.; Edgar, R. J.
It has been a puzzle for quite some time that spectroscopic measurements in the inner corona indicate electron temperatures far too low to produce the ion fractions observed in the in situ solar wind. In the present paper we show that in order to reconcile the two sets of measurements, a number of conditions have to exist in the inner corona: 1) t…