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COMPTEL three-year search for galactic sources of ^44^Ti gamma-ray line emission at 1.157MeVстатья
Информация о цитировании статьи получена из
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Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 18 июля 2013 г.
- Авторы: Dupraz C., Bloemen H., Bennett K., Diehl R., Hermsen W., Iyudin A.F., Ryan J., Schoenfelder V.
- Журнал: Astronomy and Astrophysics
- Том: 324
- Год издания: 1997
- Издательство: Springer Verlag
- Местоположение издательства: Germany
- Первая страница: 683
- Последняя страница: 689
- Аннотация: 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_).
- Добавил в систему: Июдин Анатолий Федорович