Astronomy and Astrophysics – Astrophysics
Scientific paper
Aug 1997
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1997a%26a...324..683d&link_type=abstract
Astronomy and Astrophysics, v.324, p.683-689
Astronomy and Astrophysics
Astrophysics
38
Nucleosynthesis, Gamma-Ray: Observations, Supernovae: General, Cas A, Ism: Supernova Remnants
Scientific paper
Because of its short lifetime, radioactive ^44^Ti is a probe of the supernova activity of the Galaxy during the last few centuries. The COMPTEL experiment aboard the Compton Observatory is capable of imaging sources of ^44^Ti line emission at 1.157MeV with a sensitivity of about 2x10^-5gamma/cm^2^/s. The latest known supernova remnant in the Milky Way, Cassiopeia A, has already been detected by COMPTEL (Iyudin et al. 1994A&A...284L...1I). Although no further event has been observed for 300-years, young objects still obscured by interstellar extinction may also show up in the light of decaying ^44^Ti. Using the first three years of COMPTEL observations, we have carried out a systematic 1.157MeV survey of the Galactic plane in order to search for these conjectural ^44^Ti sources. We report on the following issues: -- of the six Galactic supernovae recorded during the last millenium, only Cassiopeia A is detected by COMPTEL. The updated flux, (3.4 +/-0.9)x10^-5gamma/cm^2^/s (systematic uncertainty <~25%), is lower than previously determined and implies an initial ^44^Ti mass of 0.9 to 2.4x10^-4^Msun_ in better agreement with observational and theoretical pictures of the Cas A supernova; -- no serendipitous ^44^Ti source is detected by COMPTEL at the >=3σ level, whereas we would expect 3 detections on statistical grounds. This negative conclusion is consistent at the <5% confidence level with canonical values of the Galactic supernova rate (2.5 to 3 events per century) and ^44^Ti supernova yields (a few 10^-5^ to 10^-4^Msun_).
Bennett Kevin
Bloemen Hans
Diehl Roland
Dupraz Christophe
Hermsen Willem
No associations
LandOfFree
COMPTEL three-year search for galactic sources of ^44^Ti gamma-ray line emission at 1.157MeV. does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with COMPTEL three-year search for galactic sources of ^44^Ti gamma-ray line emission at 1.157MeV., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and COMPTEL three-year search for galactic sources of ^44^Ti gamma-ray line emission at 1.157MeV. will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1877653