Search Publications
Simultaneous EXOSAT-IUE observations of NGC 4151
Tarenghi, M.; Piro, L.; Perola, G. C. +9 more
NGC 4151 was observed four times in Nov. 83. The results indicate that: a) there exists a correlation between the X-ray and UV fluxes on the long term; b) the soft X-ray excess between 0.1 and 1 keV is probably steeper than expected from the leaky absorber model by Holt et al (1980); c)the spectral fit to the ME data, after correction for a soft c…
More on theλ2800 Å `interstellar extinction' feature
Nandy, K.; McLachlan, A.
We respond to comments made in a recent letter by Karimet al. (1984), and show that the examples of interstellar absorption atλ2800 Å that they have presented so far can all be attributed to overexposure of the IUE detectors.
High and medium resolution spectroscopy of the X-ray transient 4U1543-47
Chiappetti, L.; White, N. E.; Kahn, S. M. +1 more
Preliminary results of an EXOSAT observation of the transient X-ray source 4U1543-47 are presented. The source was observed in August 1983, during a high state, following a Tenma alert that the source was again active. Results from the GSPC and the LE 1000 l/mm grating are presented. The spectrum is complex, but in the 2 10 keV energy range can be…
EXOSAT PSD and CMA observations of the SNR PKS 1209-52
Kellett, B. J.
EXOSAT PSD images and spectra are presented of the supernova remnant (SNR) PKS 1209-52 (G296.5+9.7. Milne 23). This source was observed for 8.5 hours in June, 1983. PSD images constructed in different energy intervals reveal that the spatial structure of the SNR is energy dependent. Comparison of the PSD and CMA images with the latest radio map of…
The MG II emission in BD -0 4234
Rucinski, S. M.
The strength of the Mg II emission in this metal-poor, high-velocity binary consisting of synchronized K-type dwarfs follows the same extension of the dependence on the inverse Rossby number which holds for rapidly-rotating Population I stars. This result indicates that the efficiency of the dynamo mechanism might be independent of metal abundance.
Spectra and time variability of GX 5-1
Pietsch, W.; Brunner, H.; Kendziorra, E. +2 more
From a short observation of GX 5-1 with EXOSAT we have derived information on spectral and temporal behaviour in the energy range 1 20 keV. The source was found to be variable on time scales from 10 s to 1 h. Describing the spectrum one is forced to assume at least two spectral components. The best fit is reached using a spectrum composed of two b…
Abell 1367 and 1060 observed with EXOSAT
Westergaard, N. J.; Norgaard-Nielsen, H. U.; Hansend, L.
Two clusters of galaxies have been observed with EXOSAT to map the distribution of cool gas. For A1367 we have detected the two brightest sources found by EINSTEIN. We confirm the identification of a X-ray source with a blue object near NGC3842. By comparing the EXOSAT and the EINSTEIN count rates we can state, either that the source is variable, …
Spectral observation of the composite supernova remnant G 29.7-0.3
Braun, R.; Koch-Miramond, L.; Rocchia, R. +3 more
The X-ray properties of the supernova remnant G 29.7-0.3 are discussed based on spectral data from the EXOSAT satellite. In the 2 to 10 keV range a featureless power-law spectrum is obtained, the best-fit parameters being: energy spectral index α=-0.77, hydrogen column density on the line of sight NH=2.3.1022 cm-2.…
Mapping of the Cygnus Loop with EXOSAT
Arnaud, M.; Ballet, J.; Rocchia, R. +1 more
Three 2.104 s observations were carried out with EXOSAT on three fields following the shock from the north to the east of the Cygnus Loop supernova remnant. Due to the softness of the source, most of the photons were collected with the LE package (CMA). For each exposure we used at least three filters (4000 Å lexan, Al-Par, boron) in or…
Search for Periodicities Near 59 S in the Cos-B Gamma-Ray Data of 2CG 195+04 (geminga)
Caraveo, P. A.; Bignami, G. F.; Hermsen, W. +5 more
The COS-B data relating to five observations in the general direction of Geminga, spanning 6.7 years, were searched for pulsation near 59 s. The SAS-2 indication is not confirmed. An indication of a 59 s pulsation in the gamma ray emission from 2CG195+04 (Geminga) was reported. Early analysis of COS-B data supported the result while later improved…