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Astrophysical Journal 647 (2006) L41-L44
The Signature of ^44Ti in Cassiopeia A Revealed by IBIS/ISGRI on INTEGRAL
M. Renaud1, 2, J. Vink, A. Decourchelle2, 3, F. Lebrun1, 2, P. R. den Hartog, R. Terrier1, C. Couvreur2, J. Knödlseder4, P. Martin4, N. Prantzos5, A. M. Bykov, H. Bloemen
INTEGRAL Collaboration(s)

We report the detection of both the 67.9 and 78.4 keV 44Sc ?-ray lines in Cassiopeia A with the INTEGRAL IBIS/ISGRI instrument. Besides the robustness provided by spectroimaging observations, the main improvements compared to previous measurements are a clear separation of the two 44Sc lines together with an improved significance of the detection of the hard X-ray continuum up to 100 keV. These allow us to refine the determination of the 44Ti yield and to constrain the nature of the nonthermal continuum emission. By combining COMPTEL, BeppoSAX PDS and ISGRI measurements, we find a line flux of (2.5+/-0.3)×10-5 cm-2 s-1 leading to a synthesized 44Ti mass of 1.6+0.6-0.3×10-4 Msolar. This high value suggests that Cas A is peculiar in comparison to other young supernova remnants, from which so far no line emission from 44Ti decay has been unambiguously detected.
1 :  APC - UMR 7164 - AstroParticule et Cosmologie
2 :  DAPNIA - Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée
3 :  AIM - UMR 7158 - Astrophysique Interactions Multi-échelles
4 :  CESR - Centre d'étude spatiale des rayonnements
5 :  IAP - Institut d'Astrophysique de Paris
Physique/Astrophysique/Cosmologie et astrophysique extra-galactique

Planète et Univers/Astrophysique/Cosmologie et astrophysique extra-galactique

Planète et Univers/Astrophysique
Gamma Rays: Observations – ISM: Individual: Name: Cassiopeia A – Nuclear Reactions – Nucleosynthesis – Abundances – ISM: Supernova Remnants
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