PTF11rka: an interacting supernova at the crossroads of stripped-envelope and H-poor superluminous stellar core collapses
Abstract
The hydrogen-poor supernova (SN) PTF11rka (z = 0.0744), reported by the Palomar Transient Factory, was observed with various telescopes starting a few days after the estimated explosion time of 2011 December 5 UT and up to 432 rest-frame days thereafter. The rising part of the light curve was monitored only in the RPTF filter band, and maximum in this band was reached ~30 rest-frame days after the estimated explosion time. The light curve and spectra of PTF11rka are consistent with the core-collapse explosion of a ~10 M⊙ carbon-oxygen core evolved from a progenitor of main-sequence mass 25-40 M⊙, that liberated a kinetic energy Ek≈4 × 1051 erg, expelled ~8 M⊙ of ejecta, and synthesized ~0.5 M⊙ of 56Ni. The photospheric spectra of PTF11rka are characterized by narrow absorption lines that point to suppression of the highest ejecta velocities (≳ 15 000 km s-1). This would be expected if the ejecta impacted a dense, clumpy circumstellar medium. This in turn caused them to lose a fraction of their energy (~5 × 1050 erg), less than 2 per cent of which was converted into radiation that sustained the light curve before maximum brightness. This is reminiscent of the superluminous SN 2007bi, the light-curve shape and spectra of which are very similar to those of PTF11rka, although the latter is a factor of 10 less luminous and evolves faster in time. PTF11rka is in fact more similar to gamma-ray burst SNe in luminosity, although it has a lower energy and a lower Ek/Mej ratio.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- September 2020
- DOI:
- 10.1093/mnras/staa2191
- arXiv:
- arXiv:2007.13144
- Bibcode:
- 2020MNRAS.497.3542P
- Keywords:
-
- radiative transfer;
- stars: massive;
- galaxies: star formation;
- transients: supernovae;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 18 page, 9 figures, MNRAS, in press