High-resolution observations of gamma-ray line emission from SN 1987A

Conference · Sun Sep 25 04:00:00 EDT 1988 · AIP Conf. Proc.; (United States)

OSTI ID:6921394

Sandie, W G; Nakano, G H; Chase, Jr, L F; Fishman, G J; Meegan, C A; Wilson, R B; Paciesas, W S; Lashe, G P

A balloon-borne gamma-ray spectrometer comprising an array of high-purity germanium (HPGE) detectors was flown from Alice Springs, Australia, on October 29--30--31, norminally 250 days after the observed neutrino pulse. High-resolution data, typically 2.5 keV at 1.33 MeV, for two transists of the supernova SN 1987A were obtained along with interspersed background data. A significant net flux of gamma rays with energy 847 keV was observed from the direction of SN 1987A on each transit. No prominent gamma-ray features were seen at other energies, although data analysis is still in progress. A preliminary estimate of the line flux at 847 keV is approx.5 x 10/sup -4/ photons cm/sup -2/ s/sup -1/ with statistical significance greater than three sigma. This line may be interpreted as emission from the first excited state of /sup 56/Fe due to the radioactive decay of /sup 56/Co, providing strong evidence for nucleosynthesis in the supernova. No emission was seen from the second excited state of /sup 56/Fe at 1238 keV. A preliminary upper limit for the 1238-keV line is approx.5 x 10/sup -4/ photons cm/sup -2/ s/sup -1/. The flux estimates may be considerably altered as the systematics of the experiment are better understood.

• Research Organization: Lockheed Palo Alto Research Laboratory, 3251 Hanover St., Palo Alto, CA 94304
• OSTI ID: 6921394
• Report Number(s): CONF-871245-
• Conference Information: Journal Name: AIP Conf. Proc.; (United States) Journal Volume: 170:1
• Country of Publication: United States
• Language: English

Related Subjects

640101 -- Astrophysics & Cosmology-- Cosmic Radiation
640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AIRSHIPS
BALLOONS
BETA DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
COBALT 56
COBALT ISOTOPES
DATA
DAYS LIVING RADIOISOTOPES
DECAY
ELECTRON CAPTURE RADIOISOTOPES
ERUPTIVE VARIABLE STARS
EVEN-EVEN NUCLEI
EXPERIMENTAL DATA
GALAXIES
GAMMA SPECTRA
GAMMA SPECTROMETERS
GE SEMICONDUCTOR DETECTORS
INFORMATION
INTERMEDIATE MASS NUCLEI
IRON 56
IRON ISOTOPES
ISOTOPES
MAGELLANIC CLOUDS
MEASURING INSTRUMENTS
NICKEL 56
NICKEL ISOTOPES
NUCLEI
NUCLEOSYNTHESIS
NUMERICAL DATA
ODD-ODD NUCLEI
RADIATION DETECTORS
RADIOISOTOPES
SEMICONDUCTOR DETECTORS
SPECTRA
SPECTROMETERS
STABLE ISOTOPES
STARS
SUPERNOVAE
SYNTHESIS
VARIABLE STARS