Inverse Compton X-Ray Emission from Supernovae with Compact Progenitors: Application to SN2011fe
Hurley, K.; Costa, E.; Fransson, C.; Yamaoka, K.; Foley, R. J.; Fukazawa, Y.; Gehrels, N.; Takahashi, T.; Feroci, M.; Krimm, H.; Hughes, J. P.; Barthelmy, S.; Ohno, M.; Del Monte, E.; Slane, P.; Terada, Y.; Makishima, K.; Tashiro, M.; Soderberg, A. M.; Palmer, D. M.; Marisaldi, M.; Golovin, D.; Starr, R.; Goldsten, J.; Connaughton, V.; Boynton, W.; Fellows, C.; Harshman, K.; Mitrofanov, I. G.; Litvak, M. L.; Sanin, A. B.; Hanabata, Y.; Murakami, T.; Cummings, J.; Milisavljevic, D.; Margutti, R.; Moe, M.; Chomiuk, L.; Svinkin, D.; Chevalier, R.; Enos, H.; Briggs, M.
United States, Sweden, Italy, Japan, Russia
Abstract
We present a generalized analytic formalism for the inverse Compton X-ray emission from hydrogen-poor supernovae and apply this framework to SN 2011fe using Swift X-Ray Telescope (XRT), UVOT, and Chandra observations. We characterize the optical properties of SN 2011fe in the Swift bands and find them to be broadly consistent with a "normal" SN Ia, however, no X-ray source is detected by either XRT or Chandra. We constrain the progenitor system mass-loss rate \dot{M}< 2\times 10^{-9}\ {M_{\odot }}\ yr^{-1} (3σ c.l.) for wind velocity vw = 100 km s-1. Our result rules out symbiotic binary progenitors for SN 2011fe and argues against Roche lobe overflowing subgiants and main-sequence secondary stars if >~ 1% of the transferred mass is lost at the Lagrangian points. Regardless of the density profile, the X-ray non-detections are suggestive of a clean environment (n CSM < 150 cm-3) for 2 × 1015 <~ R <~ 5 × 1016 cm around the progenitor site. This is either consistent with the bulk of material being confined within the binary system or with a significant delay between mass loss and supernova explosion. We furthermore combine X-ray and radio limits from Chomiuk et al. to constrain the post-shock energy density in magnetic fields. Finally, we searched for the shock breakout pulse using gamma-ray observations from the Interplanetary Network and find no compelling evidence for a supernova-associated burst. Based on the compact radius of the progenitor star we estimate that the shock breakout pulse was likely not detectable by current satellites.