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COS B observation of high-energy γ radiation from 3C273

Bignami, G. F.; Hermsen, W.; Masnou, J. L. +9 more

THE discovery of a high-energy γ-ray source at α(1950) = 12h 29 min+/-6 min, δ(1950)= +3°+/-1.5° is reported here. Arguments are given for the identification with 3C273. If this identification is correct, the γ-ray luminosity of 3C273 in the energy range 50-500 MeV is 2×10⁴⁶ erg s^-1 for H₀ = 60 km s^-1 Mp…

Hard X-ray observations of cosmic γ-ray sources

Coe, M. J.; Quenby, J. J.; Engel, A. R.

THE publication¹, by workers using the COS B satellite, of a list of 13 discrete cosmic γ-ray sources has aroused considerable interest. Attention has mainly been focussed on attempts to identify all or some of these sources with known X-ray sources^2-4, optical sources^5,6, radio sources⁷ and HII regions<…

Possible X-ray counterparts of gamma-ray sources.

Maraschi, L.; Bradt, H.; Apparao, K. M. V. +5 more

The results are presented of a survey regarding the X-ray source positions which fall within the error boxes of 10 unidentified gamma-ray sources observed with the aid of the COS-B satellite. In three cases, including CG 135-1, CG 312-1, and CG 327-0, an X-ray source was found within the gamma-ray error box. However, because of the large uncertain…

Observability of gamma-ray pulsars.

Massaro, E.; Buccheri, R.; Scarsi, L. +1 more

Attention is given to the Crab (PSR 0531 plus 21) and Vela (PSR 0833 minus 45) pulsars in a study of pulsed energy release in the gamma-ray channel; with a gamma-ray/radio luminosity ratio on the order of one million. SAS 2 and COS B data are analyzed in an attempt to detect possible gamma-ray emission from other known radio pulsars. A phenomenolo…

Coincidence of compact supernova remnants with three COS-B γ-ray sources

Lamb, R. C.

POSITIONAL coincidences and a `near miss' of four small-diameter supernova remnants (SNR) with three of the 11 unidentified COS-B γ-ray sources¹ are reported here. I argue that it is unlikely that all four SNR-γ-ray source associations are accidental, and that their compactness probably indicates that their ages are not greater than abo…

On the identification of celestial γ-ray sources

Massaro, E.; Scarsi, L.

THE observations from COS B have provided a new and more detailed picture of the high energy γ-ray emission from the Galaxy. We discuss here the first catalogue with 13 localised sources which has been compiled^1,2 and how the list should lengthen in the near future, as the data analysis progresses.