Details

Autor(en) / Beteiligte

• Sand, D. J.
• Graham, M. L.
• Botyánszki, J.
• Hiramatsu, D.
• McCully, C.
• Valenti, S.
• Hosseinzadeh, G.
• Howell, D. A.
• Burke, J.
• Cartier, R.
• Diamond, T.
• Hsiao, E. Y.
• Jha, S. W.
• Kasen, D.
• Kumar, S.
• Marion, G. H.
• Suntzeff, N.
• Tartaglia, L.
• Wheeler, J. C.
• Wyatt, S.

Titel

Nebular Spectroscopy of the "Blue Bump" Type Ia Supernova 2017cbv

Ist Teil von

• The Astrophysical journal, 2018-08, Vol.863 (1), p.24

Ort / Verlag

Philadelphia: The American Astronomical Society

Erscheinungsjahr

2018

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• We present nebular phase optical and near-infrared spectroscopy of the Type Ia supernova (SN) 2017cbv. The early light curves of SN 2017cbv showed a prominent blue bump in the U, B, and g bands lasting for ∼5 days. One interpretation of the early light curve is that the excess blue light is due to shocking of the SN ejecta against a nondegenerate companion star-a signature of the single degenerate scenario. If this is the correct interpretation, the interaction between the SN ejecta and the companion star could result in significant H (or helium) emission at late times, possibly along with other species, depending on the companion star and its orbital separation. A search for H emission in our +302 d spectrum yields a nondetection, with a LH < 8.0 × 1035 erg s−1 (given an assumed distance of D = 12.3 Mpc), which we verified by implanting simulated H emission into our data. We make a quantitative comparison to models of swept-up material stripped from a nondegenerate companion star and limit the mass of hydrogen that might remain undetected to MH < 1 × 10−4 M . A similar analysis of helium star related lines yields a MHe < 5 × 10−4 M . Taken at face value, these results argue against a nondegenerate H- or He-rich companion in Roche lobe overflow as the progenitor of SN 2017cbv. Alternatively, there could be weaknesses in the envelope-stripping and radiative transfer models necessary to interpret the strong H and He flux limits.