The continuing story of SN IIb 2013df: new optical and IR observations and analysis

Abstract

SN 2013df is a nearby Type IIb supernova that seems to be the spectroscopic twin of the well-known SN 1993J. Previous studies revealed many, but not all interesting properties of this event. Our goal was to add new understanding of both the early and late-time phases of SN 2013df. Our spectral analysis is based on 6 optical spectra obtained with the 9.2m Hobby-Eberly Telescope during the first month after explosion, complemented by a near-infrared spectrum. We applied the SYNAPPS spectral synthesis code to constrain the chemical composition and physical properties of the ejecta. A principal result is the identification of "high-velocity" He I lines in the early spectra of SN 2013df, manifest as the blue component of the double-troughed profile at ∼5650Å. This finding, together with the lack of clear separation of H and He lines in velocity space, indicates that both H and He features form at the outer envelope during the early phases. We also obtained ground-based BVRI and g ′ r ′ i ′ z ′ photometric data up to +45 days and unfiltered measurements with the ROTSE-IIIb telescope up to +168 days. From the modelling of the early-time quasi-bolometric light curve, we find M ej ∼ 3.2−4.6 M ⊙ and E kin ∼ 2.6−2.8 × 10 51 erg for the initial ejecta mass and the initial kinetic energy, respectively, which agree well with the values derived from the separate modelling of the light-curve tail. Late-time mid-infrared excess indicates circumstellar interaction starting ∼1 year after explosion, in accordance with previously published optical, X-ray, and radio data.

SN 2017ivv: two years of evolution of a transitional Type II supernova

“…For this reason, we will compare SN 2017ivv to both fast-declining SNe II and SNe IIb with well-sampled light curves and some spectra during both the photospheric and nebular phase. The fast-declining SN II group consists of ASASSN-15oz (Bostroem et al 2019), SN 2014G (Terreran et al 2016), SN 2013ej (Valenti et al 2014;Huang et al 2015;Yuan et al 2016), and SN 2013by (Valenti et al 2015;Black et al 2017), while the SNe IIb sample consists of SN 2015as (Gangopadhyay et al 2018), SN 2013df (Morales-Garoffolo et al 2014;Szalai et al 2016), SN 2011hs (Bufano et al 2014), SN 2011dh (Arcavi et al 2011;Sahu et al 2013;Ergon et al 2014), SN 2008ax (Pastorello et al 2008Taubenberger et al 2011;Modjaz et al 2014), and SN 1993J (Barbon et al 1995;Matheson et al 2000). Because of the extremely low luminosity of the host of SN 2017ivv, we also include SN 2015bs (Anderson et al 2018), which is a slow-declining SN II that exploded in the faintest host galaxy found before SN 2017ivv.…”

Dust in Supernovae and Supernova Remnants I: Formation Scenarios

“…Typical ejecta dust masses reported in SNe younger than day 10,000 are between 10 −6 -10 −3 M (e.g. Sugerman et al 2006;Meikle et al 2007;Kotak et al 2006;Szalai et al 2016) and it has been suggested that the dust masses increase in time (Gall et al 2011(Gall et al , 2014. Because the measurements of late phase dust masses are limited to a few SNe (e.g.…”

A Systematic Study of Mid-Infrared Emission From Core-Collapse Supernovae With Spirits

“…SN 2013ai shows similar plateauing after 400 days at 4.5 μm to a decline rate of 0.23 mag/100 days, but there is insufficient coverage in the 3.6 μm band. For a detailed discussion of SN 2013df, see Szalai et al (2016). SN 2013am and SN 2011ja (Andrews et al 2016) rebrighten in different epochs.…”