SN2009ip: Constraints on the progenitor mass-loss rate

TL;DR

This paper constrains the progenitor's mass-loss rate of SN 2009ip using multi-wavelength observations, estimating a rate of 10^-3 to 10^-2 solar masses per year prior to explosion, informing supernova progenitor models.

Contribution

It provides the first multi-method, order-of-magnitude constraints on the pre-explosion mass-loss rate of SN 2009ip's progenitor, combining X-ray, optical, infrared, and radio data.

Findings

Mass-loss rate estimated between 10^-3 and 10^-2 solar masses per year.

Total circumstellar matter within 6x10^15 cm is approximately 0.04 solar masses.

H alpha luminosity suggests a higher mass-loss rate, indicating possible aspherical CSM or different emission regions.

Abstract

Some supernovae (SNe) show evidence for mass-loss events taking place prior to their explosions. Measuring their pre-outburst mass-loss rates provide essential information regarding the mechanisms that are responsible for these events. Here we present XMM-Newton and Swift X-ray observations taken after the latest, and presumably the final, outburst of SN 2009ip. We use these observations as well as new near infra-red and visible light spectra, and published radio and visible light observations to put six independent order-of-magnitude constrains on the mass-loss rate of the SN progenitor prior to the explosion. Our methods utilize: the X-ray luminosity, the bound-free absorption, the H alpha luminosity, the SN rise-time, free-free absorption, and the bolometric luminosity of the outburst detected prior to the explosion. Assuming spherical mass-loss with a wind density profile, we estimate that the effective mass-loss rate from the progenitor was between 10^-3 to 10^-2 solar masses per year, over a few years prior to the explosion, with a velocity of ~1000 km/s. This mass-loss rate corresponds to a total circum stellar matter mass of ~0.04 solar masses, within 6x10^15 cm of the SN. We note that the mass-loss rate estimate based on the H alpha luminosity is higher by an order of magnitude. This can be explained if the narrow line H alpha component is generated at radii larger than the shock radius, or if the CSM has an aspherical geometry. We discuss simple geometries which are consistent with our results.