The mystery of photometric twins DES17X1boj and DES16E2bjy. Issue 4 (13th April 2020)

• Record Type: Journal Article
• Authors: Pursiainen, M; Gutiérrez, C P; Wiseman, P; Childress, M; Smith, M; Frohmaier, C; Angus, C; Castro Segura, N; Kelsey, L; Sullivan, M; Galbany, L; Nugent, P; Bassett, B A; Brout, D; Carollo, D; D'Andrea, C B; Davis, T M; Foley, R J; Grayling, M; Hinton, S R; Inserra, C; Kessler, R; Lewis, G F; Lidman, C; Macaulay, E; March, M; Möller, A; Müller, T; Scolnic, D; Sommer, N E; Swann, E; Thomas, B P; Tucker, B E; Vincenzi, M; Abbott, T M C; Allam, S; Annis, J; Avila, S; Bertin, E; Brooks, D; Buckley-Geer, E; Burke, D L; Carnero Rosell, A; Carrasco Kind, M; da Costa, L N; De Vicente, J; Desai, S; Diehl, H T; Doel, P; Eifler, T F; Everett, S; Flaugher, B; Frieman, J; García-Bellido, J; Gaztanaga, E; Gerdes, D W; Gruen, D; Gruendl, R A; Gschwend, J; Gutierrez, G; Hollowood, D L; Honscheid, K; James, D J; Kim, A G; Krause, E; Kuehn, K; Maia, M A G; Marshall, J L; Menanteau, F; Miquel, R; Ogando, R L C; Palmese, A; Paz-Chinchón, F; Plazas, A A; Roodman, A; Sanchez, E; Scarpine, V; Schubnell, M; Serrano, S; Sevilla-Noarbe, I; Suchyta, E; Swanson, M E C; Tarle, G; Wester, W;
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 494:Issue 4(2020)
• Page Start: 5576
• Page End: 5589
• Publication Date: 2020-04-13
• Subjects: supernovae: general; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/staa995
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: We present an analysis of DES17X1boj and DES16E2bjy, two peculiar transients discovered by the Dark Energy Survey (DES). They exhibit nearly identical double-peaked light curves that reach very different maximum luminosities ( M r = −15.4 and −17.9, respectively). The light-curve evolution of these events is highly atypical and has not been reported before. The transients are found in different host environments: DES17X1boj was found near the nucleus of a spiral galaxy, while DES16E2bjy is located in the outskirts of a passive red galaxy. Early photometric data are well fitted with a blackbody and the resulting moderate photospheric expansion velocities (1800 km s −1 for DES17X1boj and 4800 km s −1 for DES16E2bjy) suggest an explosive or eruptive origin. Additionally, a feature identified as high-velocity Ca ii absorption ($v$ ≈ 9400 km s −1 ) in the near-peak spectrum of DES17X1boj may imply that it is a supernova. While similar light-curve evolution suggests a similar physical origin for these two transients, we are not able to identify or characterize the progenitors.