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The Spectral and Temporal Variability of the X-Ray Transient 4U1630-47
Stella, L.; Parmar, A. N.; White, N. E.
We present the results of four observations made by the European Space Agency's EXOSAT Observatory of the X-ray transient 4U1630-47 during its 1984 outburst. We observed marked spectral changes as the source decayed from a maximum observed intensity of 8×10-9 erg/cm2/sec (1.5 10 keV). The spectrum could be modelled by a soft …
2 10 KeV spectra of Crab-like SNR's as observed by EXOSAT
Smith, A.; Davelaar, J.
The EXOSAT ME observations of 3C58 and G21.5-0.9 are presented. The data for these objects is considered in conjunction with the data available from EXOSAT for the Crab-like SNR's Crab and Vela X. The objects have single power law spectra with a range of spectral indices of 0.6 to 1.5, 3C58 and Vela X being similar to the Crab whilst G21.5-0.9 and…
Some crucial X-ray observations — One or two SNR(s) in Crux?
Caraveo, P. A.; Bignami, G. F.; Mereghetti, S. +2 more
A new EXOSAT (LE/CMA) observation of the region in Crux (R.A. ∼11h 45m, Dec. ∼-62°) where Markert et al. (1981) reported the existence of two x-ray SNR's is presented. After “cleaning” the CMA field from the point source component, due to the UV emission of the numerous stars in the field, the smoothed x-ray contours are compared to the 408 MHz ra…
A New View of the Galactic Plane with EXOSAT
Warwick, R. S.; Watson, M. G.; Turner, M. J. L. +1 more
A new X-ray image of the galactic plane has been produced using the 45 arcmin square field of view of the Medium Energy Instrument on EXOSAT. This image shows a total of 64 sources including 18 new ones which include the first observation of persistent emission from the globular cluster bursters Terzan 1 and Terzan 5. The most important discovery …
EXOSAT Observations of Bursts from 2S1636-536 - Burst Morphology
Turner, M. J. L.; Ohashi, T.; Breedon, L. M.
In two observations with the EXOSAT ME a total of 11 bursts were detected; 7 in July and 4 in May 1984. In terms of rise time and peak count rate there are only 2 kinds, those with a sharp rise and peak count rate of 500 cts/sec/detector and those with a slow rise and a peak count rate of 200 cts/sec/detector. The spectral analysis of these bursts…
H0323+022 - Classification as a Bl-Lacertae and EXOSAT Coordinated Observations
McHardy, I.; McClintock, J. E.; Remillard, R. +18 more
The object H0323+022 (Doxsey et al. 1983) has been shown to be a BL Lac object by virtue of a diversity of observational characteristics at radio, optical, and x-ray wavelengths, in agreement with the conclusion of Margon and Jacoby (1984). Multi-frequency coordinated observations of this highly variable object with EXOSAT in September 1984 found …
Coordinated EXOSAT and Optical Observations of the X-Ray Burster 4U1737-44
Charles, P. A.; Corbet, R. H. D.; Smale, A. P. +2 more
We present the first results of an EXOSAT observation of the low-mass X-ray burster 4U1735-44. The ME data show low-amplitude variations in the persistent flux including two 5% dips separated by ∼4 hours. The structure of the single observed burst is briefly described. Five hours of simultaneous B-band photometry were obtained at SAAO with 12 minu…
EXOSAT spectra of some bright QSO's
Tennant, A. F.; Stewart, G. C.; Shafer, R. A. +1 more
This paper reports on EXOSAT observations of four bright QSO's and active galaxies. The QSO PHL 1657 has a simple spectrum that can be fit with power law plus some low energy absorption. A soft excess is observed for both MR 2251 and E 1352.24+1830. Finally, PKS 2126-158 was detected and the results are consistent with a 0.7 energy index.
The Quiescent Spectrum of 2S1636-536
King, A.; Turner, M. J. L.; Breedon, L. M. +1 more
During the EXOSAT observation of 2S1636-536 in July 1983 the quiescent flux was observed to brighten from 1.7×10 -9 ergs/cm. 2 /sec to 2.6×10-9 ergs/cm. 2 /sec, this increase being accompanied by a decrease in effective temperature. Further analysis of the spectrum reveals that the best fit is a power …
EXOSAT observation of the QSO galaxy pair 1E0104.2+3153
Giommi, P.; Maccacaro, T.; Gioia, I. M.
A very long (160,000 second) observation of the X-ray source 1E0104.2+3153 was carried out using the Channel Multiplier Array (CMA) instrument on board Exosat in August 17, 1984. A thin Lexan filter having maximum throughput in the 0.05-2.0 keV CMA band was used during the entire observation period. The positional accuracy of the CMA was sufficien…