The early phases of the type Iax supernova SN 2011ay

Szalai, Tamás and Vinkó, József and Sárneczky, Krisztián and Takáts, Katalin and Benkő, József and Kelemen, János (2015) The early phases of the type Iax supernova SN 2011ay. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 453 (2). pp. 2103-2114. ISSN 0035-8711

Preview

Text 1508.00602.pdf Available under License Creative Commons Attribution. Download (850kB) | Preview

Abstract

We present a detailed study of the early phases of the peculiar supernova 2011ay based on BVRI photometry obtained at Konkoly Observatory, Hungary, and optical spectra taken with the Hobby-Eberly Telescope at McDonald Observatory, Texas. The spectral analysis carried out with SYN++ and SYNAPPS confirms that SN 2011ay belongs to the recently defined class of SNe Iax, which is also supported by the prop- erties of its light and color curves. The estimated photospheric temperature around maximum light, Tphot ∼ 8,000 K, is lower than in most Type Ia SNe, which results in the appearance of strong Fe II features in the spectra of SN 2011ay, even during the early phases. We also show that strong blending with metal features (those of Ti II, Fe II, Co II) makes the direct analysis of the broad spectral features very difficult, and this may be true for all SNe Iax. We find two alternative spectrum models that both describe the observed spectra adequately, but their photospheric velocities differ by at least ∼ 3, 000 km s−1. The quasi-bolometric light curve of SN 2011ay has been assem- bled by integrating the UV-optical spectral energy distributions. Fitting a modified Arnett-model to Lbol(t), the moment of explosion and other physical parameters, i.e. the rise time to maximum, the 56Ni mass and the total ejecta mass are estimated as trise ∼14±1 days, MN i ∼0.22±0.01 M⊙ and Mej ∼ 0.8 M⊙, respectively.

Actions (login required)

Edit Item