Inverse Compton X-ray Emission from Supernovae with Compact Progenitors: Application to SN2011fe

TL;DR

This paper develops a formalism for inverse Compton X-ray emission from hydrogen-poor supernovae, applies it to SN2011fe, and constrains its progenitor system and environment through multi-wavelength observations, ruling out certain progenitor models.

Contribution

It introduces a generalized analytic model for inverse Compton X-ray emission and applies it to SN2011fe, providing new constraints on its progenitor system and circumstellar environment.

Findings

Progenitor mass loss rate < 2x10^-9 M_sun/yr (3σ)

No X-ray source detected by Swift-XRT or Chandra

Environment density < 150 cm^-3 around the progenitor

Abstract

We present a generalized analytic formalism for the inverse Compton X-ray emission from hydrogen-poor supernovae and apply this framework to SN2011fe using Swift-XRT, UVOT and Chandra observations. We characterize the optical properties of SN2011fe 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 to be lower than 2x10^-9 M_sun/yr (3sigma c.l.) for wind velocity v_w=100 km/s. Our result rules out symbiotic binary progenitors for SN2011fe 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 (particle density < 150 cm-3) for (2x10^15<R<5x10^16) 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. 2012 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 break out pulse was likely not detectable by current satellites.