Supplementary information
From the following article:
Radioactive 26Al from massive stars in the Galaxy
Roland Diehl, Hubert Halloin, Karsten Kretschmer, Giselher G. Lichti, Volker Schönfelder, Andrew W. Strong, Andreas von Kienlin, Wei Wang, Pierre Jean, Jürgen Knödlseder, Jean-Pierre Roques, Georg Weidenspointner, Stephane Schanne, Dieter H. Hartmann, Christoph Winkler and Cornelia Wunderer
Nature 439, 45-47 (5 January 2006)
doi:10.1038/nature04364
Supplementary Methods
Observations and Data. The INTEGRAL Observatory and its spectrometer instrument have been launched in Oct 2002. Observations are composed of 7130 pointings along the plane of the Galaxy, and sum up to an exposure of 4 Ms at the Galactic Center, from the first two years of the mission.
Supplementary Methods
Data Analysis and Results. Spectra are determined from independent model fits in 0.5 keV bins. Splitting the sky model into longitude segments allows for spatially-resolved spectroscopy, and obtains Doppler shifts as expected from Galactic rotation. The variability of resulting spectra with different models for the spatial distribution of 26Al emission is modest to small.
Supplementary Discussion
Doppler Broadening. The width of the observed gamma-ray line depends on the state of the ISM.
Supplementary Discussion
Galactic Rotation. Different models for the spatial distribution of 26Al emission and rotation curves for the inner Galaxy lead to variations in expected line shifts.
Supplementary Discussion
Nucleosynthesis Yields. Different models for stellar evolution and supernovae predict somewhat different yields of 26Al. From current models, an assessment is made over the full range of massive stars.
Supplementary Methods
Deriving a Galactic Star Formation Rate from 26Al Gamma-rays. The determination of the supernova rate follows from the nucleosynthesis yield and its integration over the mass distribution of stars. The conversion to a star formation rate is described.
Supplementary Discussion
Star Formation Rate (SFR) and Supernova Rate (SNR) Estimates for the Galaxy. The different approaches determining supernova rates or star formation rates for the Galaxy are presented in a Table, with discussion of strengths and weaknesses. The 26Al-based approach is completely independent, and among the less-biased and more accurate methods.
DOWNLOAD BROWSER PLUGINS AND OTHER APPLICATIONS
Movie files
PDF douments
Text documents
PostScript documents
Flash movies
Audio files
- Apple iTunes (PC or Mac)
- QuickTime Player (PC or Mac)
- Realplayer (PC or Mac)
- Windows Media player (PC only)
