Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Series

Astrophysics and Astronomy

Physics & Astronomy

Gamma rays

Publication Year

Articles 1 - 2 of 2

Full-Text Articles in Physical Sciences and Mathematics

Gamma-Ray Observations Of Gro J1655-40, R Kroeger, Mark Strickman, J E. Grove, Philip Kaaret, E. Ford, B A. Harmon, Mark L. Mcconnell Dec 1996

Gamma-Ray Observations Of Gro J1655-40, R Kroeger, Mark Strickman, J E. Grove, Philip Kaaret, E. Ford, B A. Harmon, Mark L. Mcconnell

Physics & Astronomy

The bright transient X-ray source GRO J1655-40 = XN Sco 1994 was observed by the OSSE instrument on the Compton Gamma Ray Observatory (GRO). Preliminary results are reported here. The initial outburst from GRO J1655-40 was detected by BATSE on 27 Jul 1994. OSSE observations were made in five separate viewing periods starting between 4 Aug 1994 and 4 Apr 1995. The first, third, and fifth observations are near the peak luminosity. In the second observation, the source flux had dropped by several orders of magnitude and we can only set an upper limit. The fourth observation is a weak …


Gamma-Ray Observations Of Cygnus X-1 And Cygnus X-3 Using A Coded-Aperture Telescope, Mark L. Mcconnell, D J. Forrest, A Owens, P. P. Dunphy, W T. Vestrand, E. L. Chupp Aug 1989

Gamma-Ray Observations Of Cygnus X-1 And Cygnus X-3 Using A Coded-Aperture Telescope, Mark L. Mcconnell, D J. Forrest, A Owens, P. P. Dunphy, W T. Vestrand, E. L. Chupp

Physics & Astronomy

A balloon-borne coded-aperture telescope, measuring gamma-ray photons in the 160 keV to 9.3 MeV range, was used to observe the Cygnus region of the sky on October 1 and 2, 1984. In the 2-9.3-MeV band, evidence is found for a hard spectral component with a mean flux level at the top of the atmosphere of 7.4 + or - 2.5 x 10 to the -7th photons/sq cm per s per keV, inconsistent with the predictions of the inverse Compton models normally used to describe the X-ray emission. Both Cyg X-1 and Cyg X-3 could be observed simultaneously with the telescope. …