Grayling, M;
Gutierrez, CP;
Sullivan, M;
Wiseman, P;
Vincenzi, M;
Gonzalez-Gaitan, S;
Tucker, BE;
... Wilkinson, RD; + view all
(2021)
Understanding the extreme luminosity of DES14X2fna.
Monthly Notices of the Royal Astronomical Society
, 505
(3)
pp. 3950-3967.
10.1093/mnras/stab1478.
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Abstract
We present DES14X2fna, a high-luminosity, fast-declining Type IIb supernova (SN IIb) at redshift z = 0.0453, detected by the Dark Energy Survey (DES). DES14X2fna is an unusual member of its class, with a light curve showing a broad, luminous peak reaching Mr ≃ −19.3 mag 20 d after explosion. This object does not show a linear decline tail in the light curve until ≃60 d after explosion, after which it declines very rapidly (4.30 ± 0.10 mag 100 d−1 in the r band). By fitting semi-analytic models to the photometry of DES14X2fna, we find that its light curve cannot be explained by a standard 56Ni decay model as this is unable to fit the peak and fast tail decline observed. Inclusion of either interaction with surrounding circumstellar material or a rapidly-rotating neutron star (magnetar) significantly increases the quality of the model fit. We also investigate the possibility for an object similar to DES14X2fna to act as a contaminant in photometric samples of SNe Ia for cosmology, finding that a similar simulated object is misclassified by a recurrent neural network (RNN)-based photometric classifier as an SN Ia in ∼1.1–2.4 per cent of cases in DES, depending on the probability threshold used for a positive classification.
| Type: | Article |
|---|---|
| Title: | Understanding the extreme luminosity of DES14X2fna |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1093/mnras/stab1478 |
| Publisher version: | https://doi.org/10.1093/mnras/stab1478 |
| Language: | English |
| Additional information: | This version is the version of record. For information on re-use, please refer to the publisher’s terms and conditions. |
| Keywords: | supernovae: general, supernovae: individual: DES14X2fna |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10133005 |
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