5 papers
EVN Observations of the BL Lac object ON 231
F. Mantovani, E. Massaro, R. Fanti +3
New EVN images at 5.0 GHz and 8.4 GHz of ON 231 confirm the complex structure of the source, the identification of the core, the presence of components on the two sides of the core…
Two BeppoSAX observations of BL Lac
G. Tagliaferri, G. Ghisellini, M. Ravasio +14
We present the results of two ToO BeppoSAX observations of BL Lac. During the first observation we detected both the synchrotron and the Compton components. Fast time variability w…
The concave X-ray spectrum of the blazar ON 231: the signature of intermediate BL Lac objects
G. Tagliaferri, G. Ghisellini, P. Giommi +17
ON 231 was observed with BeppoSAX in May and June 1998, following an exceptional optical outburst which occured in April--May. We measured the X-ray spectrum from 0.1 up to 100 keV…
Synchrotron and Inverse Compton Variability in the BL Lacertae object S5 0716+714
P. Giommi, E. Massaro, L. Chiappetti +14
We report intensity variations of different spectral components in the BL Lac object S5 0716+714 detected during coordinated BeppoSAX and optical observations in 1996 and 1998. The…
A ROSAT Hri Obsrevation of the Cooling Flow Cluster MS0839.9+2938
R. Nesci, G. C. Perola, A. Wolter
A ROSAT HRI observation of the cluster MS0839.9+2938 at z=0.194 is presented. It confirms the earlier suggestion, based on the detection of extended H emission, that the inner r…