Wind of presupernova IIn SN~1997eg

Abstract

Spectra and phototometry of type IIn supernova SN 1997eg are used to determine properties of the circumstellar gas lost by the presupernova during the latest 200 years before the explosion. The analysis of narrow H$\alpha$ and [Fe X] 6374 Å results in the wind velocity $u=20$ km/s, significantly lower than the earlier accepted value (160 km/s) upon the bases of the radial velocity of a blue absorption wing of the narrow H$\alpha$. That high velocity of the wind in our picture is related to the preshock gas accelerated by the cosmic ray precursor. The modelling of the circumstellar interaction results in the wind density parameter $\dot{M}/u$ that being combined with the wind velocity suggests the presupernova mass loss rate of $1.6\cdot 10^{-3}{M}_{\odot }$ yr${}^{-1}$. The wind density is consistent with the [Fe X] 6374 Å luminosity. The model H$\alpha$ luminosity also agrees with the observational value. Recovered wind properties indicate that the presupernova at the final evolutionary stage was a massive red supergiant with a high mass loss rate, but not the LBV-supergiant as suggested earlier.

Astronomy Letters (accepted)

References in corpus (5)

• Pulsational pair instability as an explanation for the most luminous supernovae
• Shell-shocked diffusion model for the light curve of SN2006gy
• Measuring the cosmic ray acceleration efficiency of a supernova remnant
• The Dual-Axis Circumstellar Environment of the Type IIn Supernova 1997eg
• SUBARU HDS Observations of a Balmer-Dominated Shock in Tycho's Supernova Remnant

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• SN 2008iy circumstellar interaction: Bright and lesser light effect