Details

Autor(en) / Beteiligte

• Fremling, C.
• Ko, H.
• Dugas, A.
• Ergon, M.
• Sollerman, J.
• Bagdasaryan, A.
• Barbarino, C.
• Belicki, J.
• Bellm, E.
• Blagorodnova, N.
• De, K.
• Dekany, R.
• Frederick, S.
• Gal-Yam, A.
• Goldstein, D. A.
• Golkhou, V. Z.
• Graham, M.
• Kasliwal, M.
• Kowalski, M.
• Kulkarni, S. R.
• Kupfer, T.
• Laher, R. R.
• Masci, F. J.
• Miller, A. A.
• Neill, J. D.
• Perley, D. A.
• Rebbapragada, U. D.
• Riddle, R.
• Rusholme, B.
• Schulze, S.
• Smith, R. M.
• Tartaglia, L.
• Yan, Lin
• Yao, Y.

Titel

ZTF18aalrxas: A Type IIb Supernova from a Very Extended Low-mass Progenitor

Ist Teil von

• Astrophysical journal. Letters, 2019-06, Vol.878 (1), p.L5

Ort / Verlag

Austin: The American Astronomical Society

Erscheinungsjahr

2019

Link zum Volltext

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• We investigate ZTF18aalrxas, a double-peaked Type IIb core-collapse supernova (SN) discovered during science validation of the Zwicky Transient Facility. ZTF18aalrxas was discovered while the optical emission was still rising toward the initial cooling peak (0.7 mag over 2 days). Our observations consist of multi-band (ultraviolet and optical) light curves (LCs), and optical spectra spanning from 0.7 to 180 days past the explosion. We use a Monte-Carlo based non-local thermodynamic equilibrium model that simultaneously reproduces both the 56Ni-powered bolometric LC and our nebular spectrum. This model is used to constrain the synthesized radioactive nickel mass (0.17 M☉) and the total ejecta mass (1.7 M☉) of the SN. The cooling emission is modeled using semi-analytical extended envelope models to constrain the progenitor radius (790-1050 R ) at the time of explosion. Our nebular spectrum shows signs of interaction with a dense circumstellar medium (CSM), and this spectrum is modeled and analyzed to constrain the amount of ejected oxygen (0.3-0.5 M☉) and the total hydrogen mass ( 0.15 M☉) in the envelope of the progenitor. The oxygen mass of ZTF18aalrxas is consistent with a low (12-13 M☉) zero-age main-sequence mass progenitor. The LCs and spectra of ZTF18aalrxas are not consistent with massive single-star SN Type IIb progenitor models. The presence of an extended hydrogen envelope of low mass, the presence of a dense CSM, the derived ejecta mass, and the late-time oxygen emission can all be explained in a binary model scenario.