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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…
Spectral characteristics of the galactic gamma radiation observed by COS-B.
Bignami, G. F.; Hermsen, W.; Bennett, K. +8 more
The ESA satellite COS-B has measured the high-energy gamma-ray emission from several regions of the galactic disk. The energy spectra of this emission have been measured. The energy spectra of the gamma radiation in the range from 50 MeV to a few GeV derived from six different longitude intervals have essentially the same shape, which resembles ne…
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 sources2-4, optical sources5,6, radio sources7 and HII regions<…
Evidence of a Continuous Change in the Period of Cygnus X-3
Manzo, G.; Molteni, D.; Robba, N. R.
Summary. Cygnus X-3 has been observed, in the 2-12 keV energy range, continuously from 1977 June 8.46 to 1977 July 14.79 by the ESA satellite COS-B. The basic parameters of the system have been determined. A fit of the COS-B data with the values obtained previously by ANS and Uhuru gives: Pdot=(2.83+/-0.67)10^-9 s/s The value Pdot/P0=(5.2+/-1.2) 1…
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…
Relative phases of radio and gamma-ray pulses from the Vela pulsar.
Hermsen, W.; Masnou, J. L.; Manchester, R. N. +7 more
Gamma-ray observations from the COS-B satellite and radio pulse-timing measurements from the Tidbinbilla Deep Space Station are used to determine accurately the relative phases of the radio (2295 MHz) and gamma-ray (above 50 MeV) pulses from the Vela pulsar. Two independent analysis procedures are employed, and both show that the peak of the radio…
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…
COS-B X-ray observations of Cygnus X-3.
Manzo, G.; Molteni, D.; Robba, N. R. +2 more
The ESA COS-B satellite has observed the Cygnus region in the energy range (2-12 keV), between 1975 November 28.42 and December 24.26. The Cygnus X-3 4.8 h modulation is detected. The source was in a low state with a positive evidence for an increase in flux during the month of observation.
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 compiled1,2 and how the list should lengthen in the near future, as the data analysis progresses.