News:
Extension http://www.sciops.esa.int/SD/INTEGRAL/docs/INTEGRAL_extension_2010_science_case.pdf 18th November 2010: ESA’s scientific advisory bodies have approved the request to extend the science operations of the INTEGRAL mission until 31 December 2014. Following the standard process, the advisory bodies will be requested in 2012 to reconfirm the extension.
Churazov positrons http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2966.2010.17804.x/pdf intro The authors analyse SPI/INTEGRAL data on the 511-keV line from the Galactic Centre, accumulated over 6 yr of observations. It is found that most of the positrons annihilate only after the gas has cooled down to 105 K, giving rise to annihilation emission characteristic of a warm, ionized ISM. caption The Figure shows Scans (produced by light-bucket imaging) along the Galactic plane in three energy bands. Fluxes are averaged over 2 degree bins over l and ±8 degrees over b. For the 1804–1813 keV band, the width of the bins along l is 4 degrees. By construction, all points are statistically independent. The positions of the Crab nebula, CygX-1 and Centaurus A are marked with the vertical dotted lines.
Diehl http://adsabs.harvard.edu/abs/2010A%26A…522A..51D intro The paper reports a search for 26Al ?-ray emission from the nearby Sco-Cen association and its subgroups with the Compton Observatory and INTEGRAL gamma-ray instruments. caption The gamma-ray spectrum of the Sco-Cen region. This was obtained from fitting a 10 degrees diameter patch of the sky representing candidate 26Al sources of this region together with a large-scale Galactic-emission model (here: MREM 26Al image as derived from COMPTEL observations) in narrow energy bins to SPI observation data.
Pierrick http://adsabs.harvard.edu/abs/2010A%26A…519A.100M intro A promising source of the positrons that contribute through annihilation to the diffuse Galactic 511 keV emission is the ß+ decay of unstable nuclei like Ni(56) and Ti(44) synthesised by massive stars and supernovae. The transport of ~MeV positrons inside SNe/SNRs cannot be constrained from current observations of the 511 keV emission from these objects, but the limits obtained on their escape fraction are consistent with a nucleosynthesis origin of the positrons that give rise to the diffuse Galactic 511 keV emission. table caption Upper limits on the 511 keV flux in units of 10-5 ph cm-2 s-1, in three different energy bands and for various source sizes for SN1006 and Tycho. Also listed are the INTEGRAL/SPI exposure for each object in cm2 s.
