Rapidly evolving transients in the Dark Energy Survey
Creators: name: Pursiainen, M.
name: Childress, M.
name: Smith, M.
name: Prajs, S.
name: Sullivan, M.
name: Davis, Timothy
name: Foley, R. J.
name: Asorey Barreiro, Jacobo
name: Calcino, J.
name: Carollo, D.
name: Curtin, C.
name: D'Andrea, C. B.
name: Glazebrook, Karl
name: Gutierrez, C.
name: Hinton, S. R.
name: Hoormann, J. K.
name: Inserra, C.
name: Kessler, R.
name: King, A.
name: Kuehn, K.
name: Lewis, G. F.
name: Lidman, C.
name: Macaulay, E.
name: Moller, Anais
name: Nichol, R. C.
name: Sako, M.
name: Sommer, N. E.
name: Swann, E.
name: Tucker, B. E.
name: Uddin, S. A.
name: Wiseman, P.
name: Zhang, B.
name: Abbott, T. M.C.
name: Abdalla, F. B.
name: Allam, S.
name: Annis, J.
name: Avila, S.
name: Brooks, D.
name: Buckley-Geer, E.
name: Burke, D. L.
name: Rosell, A. Carnero
name: Kind, M. Carrasco
name: Carretero, J.
name: Castander, F. J.
name: Cunha, C. E.
name: Davis, C.
name: De Vicente, J.
name: Diehl, H. T.
name: Doel, P.
name: Eifler, T. F.
name: Flaugher, B.
name: Fosalba, P.
name: Frieman, J.
name: García-Bellido, J.
name: Gruen, D.
name: Gruendl, R. A.
name: Gutierrez, G.
name: Hartley, W. G.
name: Hollowood, D. L.
name: Honscheid, K.
name: James, D. J.
name: Jeltema, T.
name: Kuropatkin, N.
name: Li, T. S.
name: Lima, M.
name: Maia, M. A.G.
name: Martini, P.
name: Menanteau, F.
name: Ogando, R. L.C.
name: Plazas, A. A.
name: Roodman, A.
name: Sanchez, E.
name: Scarpine, V.
name: Schindler, R.
name: Smith, R. C.
name: Soares-Santos, M.
name: Sobreira, F.
name: Suchyta, E.
name: Swanson, M. E.C.
name: Tarle, G.
name: Tucker, D. L.
name: Walker, A. R.
Publisher: name: Swinburne
Year: 2024

description: We present the results of a search for rapidly evolving transients in the Dark Energy Survey Supernova Programme. These events are characterized by fast light-curve evolution (rise to peak in≲10 d and exponential decline in≲30 d after peak).We discovered 72 events, including 37 transients with a spectroscopic redshift from host galaxy spectral features. The 37 events increase the total number of rapid optical transients by more than a factor of two. They are found at a wide range of redshifts (0.05 &lt; z &lt; 1.56) and peak brightnesses (-15.75 &gt; Mg &gt; -22.25). The multiband photometry is well fit by a blackbody up to few weeks after peak. The events appear to be hot (T ≈ 10 000-30 000 K) and large (R ≈ 1014 - 2 × 1015 cm) at peak, and generally expand and cool in time, though some events show evidence for a receding photosphere with roughly constant temperature. Spectra taken around peak are dominated by a blue featureless continuum consistent with hot, optically thick ejecta. We compare our events with a previously suggested physical scenario involving shock breakout in an optically thick wind surrounding a core-collapse supernova, we conclude that current models for such a scenario might need an additional power source to describe the exponential decline. We find that these transients tend to favour star-forming host galaxies, which could be consistent with a core-collapse origin. However, more detailed modelling of the light curves is necessary to determine their physical origin.