TY - JOUR
T1 - Supernova shock breakout through a wind
AU - Balberg, Shmuel
AU - Loeb, Abraham
PY - 2011/6
Y1 - 2011/6
N2 - The breakout of a supernova shock wave through the progenitor star's outer envelope is expected to appear as an X-ray flash. However, if the supernova explodes inside an optically thick wind, the breakout flash is delayed. We present a simple model for estimating the conditions at shock breakout in a wind based on the general observable quantities in the X-ray flash light curve; the total energy EX, and the diffusion time after the peak, tdiff. We base the derivation on the self-similar solution for the forward-reverse shock structure expected for an ejecta plowing through a pre-existing wind at large distances from the progenitor's surface. We find simple quantitative relations for the shock radius and velocity at breakout. By relating the ejecta density profile to the pre-explosion structure of the progenitor, the model can also be extended to constrain the combination of explosion energy and ejecta mass. For the observed case of XRO08109/SN2008D, our model provides reasonable constraints on the breakout radius, explosion energy and ejecta mass, and predicts a high shock velocity which naturally accounts for the observed non-thermal spectrum.
AB - The breakout of a supernova shock wave through the progenitor star's outer envelope is expected to appear as an X-ray flash. However, if the supernova explodes inside an optically thick wind, the breakout flash is delayed. We present a simple model for estimating the conditions at shock breakout in a wind based on the general observable quantities in the X-ray flash light curve; the total energy EX, and the diffusion time after the peak, tdiff. We base the derivation on the self-similar solution for the forward-reverse shock structure expected for an ejecta plowing through a pre-existing wind at large distances from the progenitor's surface. We find simple quantitative relations for the shock radius and velocity at breakout. By relating the ejecta density profile to the pre-explosion structure of the progenitor, the model can also be extended to constrain the combination of explosion energy and ejecta mass. For the observed case of XRO08109/SN2008D, our model provides reasonable constraints on the breakout radius, explosion energy and ejecta mass, and predicts a high shock velocity which naturally accounts for the observed non-thermal spectrum.
KW - Shock waves
KW - Stars: winds, outflows
KW - Supernovae: general
KW - Supernovae: individual: SN 2008D
UR - http://www.scopus.com/inward/record.url?scp=79958151389&partnerID=8YFLogxK
U2 - 10.1111/j.1365-2966.2011.18505.x
DO - 10.1111/j.1365-2966.2011.18505.x
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AN - SCOPUS:79958151389
SN - 0035-8711
VL - 414
SP - 1715
EP - 1720
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 2
ER -