Understanding the extreme luminosity of DES14X2fna Academic Article uri icon


  • 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 19.3mag 20d after explosion. This object does not show a linear decline tail in the light curve until 60d after explosion, after which it declines very rapidly (4.300.10 mag 100 d1 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 1.12.4percent of cases in DES, depending on the probability threshold used for a positive classification.

published proceedings


altmetric score

  • 0.5

author list (cited authors)

  • Grayling, M., Gutierrez, C. P., Sullivan, M., Wiseman, P., Vincenzi, M., Gonzalez-Gaitan, S., ... Collaboration, D.

citation count

  • 1

complete list of authors

  • Grayling, M||Gutiérrez, CP||Sullivan, M||Wiseman, P||Vincenzi, M||González-Gaitán, S||Tucker, BE||Galbany, L||Kelsey, L||Lidman, C||Swann, E||Smith, M||Frohmaier, C||Carollo, D||Glazebrook, K||Lewis, GF||Möller, A||Hinton, SR||Uddin, SA||Abbott, TMC||Aguena, M||Avila, S||Bertin, E||Bhargava, S||Brooks, D||Carnero Rosell, A||Carrasco Kind, M||Carretero, J||Costanzi, M||da Costa, LN||De Vicente, J||Desai, S||Diehl, HT||Doel, P||Everett, S||Ferrero, I||Fosalba, P||Frieman, J||García-Bellido, J||Gaztanaga, E||Gruen, D||Gruendl, RA||Gschwend, J||Gutierrez, G||Hoyle, B||Kuehn, K||Kuropatkin, N||Lima, M||MacCrann, N||Marshall, JL||Martini, P||Miquel, R||Morgan, R||Palmese, A||Paz-Chinchón, F||Plazas, AA||Romer, AK||Sánchez, C||Sanchez, E||Scarpine, V||Serrano, S||Sevilla-Noarbe, I||Soares-Santos, M||Suchyta, E||Tarle, G||Thomas, D||To, C||Varga, TN||Walker, AR||Wilkinson, RD

publication date

  • June 2021