Volume 539, March 2012
|Number of page(s)||4|
|Published online||29 February 2012|
Constraints on the non-thermal emission from η Carinae’s blast wave of 1843
1 Max-Planck-Institut für Kernphysik, PO Box 103980, 69029 Heidelberg, Germany
2 X-ray and Observational Astronomy Group, Department of Physics and Astronomy, University of Leicester, LE1 7RH, UK
3 School of Physics and Astronomy, University of Leeds, LS2 9JP, UK
4 CSIRO Astronomy and Space Science, PO Box 76, Epping, NSW 1710, Australia
Received: 10 November 2011
Accepted: 3 January 2012
Non-thermal hard X-ray and high-energy (HE; 1 MeV < E < 100 GeV) γ-ray emission in the direction of η Carinae has been recently detected using the INTEGRAL, AGILE and Fermi satellites. This emission has been interpreted either in the framework of particle acceleration in the colliding wind region between the two massive stars or in the very fast moving blast wave which originates in the historical 1843 “great eruption”. Archival Chandra data has been reanalysed to search for signatures of particle acceleration in η Carinae’s blast wave. No shell-like structure could be detected in hard X-rays and a limit has been placed on the non-thermal X-ray emission from the shell. The time dependence of the target radiation field of the Homunculus is used to develop a single zone model for the blast wave. Attempting to reconcile the X-ray limit with the HE γ-ray emission using this model leads to a very hard electron injection spectrum dN/dE ∝ E − Γ with Γ < 1.8, harder than the canonical value expected from diffusive shock acceleration.
Key words: acceleration of particles / X-rays: stars / binaries: general / gamma rays: stars / stars: individual: η Carinae
© ESO, 2012
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.