| Title | SN 2016gsd: an unusually luminous and linear Type II supernova with high velocities |
| Authors | Reynolds, T. M. Fraser, M. Mattila, S. Ergon, M. Lundqvist, P. Dessart, L. Dong, Subo Elias-Rosa, N. Galbany, L. Gutierrez, C. P. Kangas, T. Kankare, E. Kotak, R. Kuncarayakti, H. Pastorello, A. Rodriguez, O. Smartt, S. J. Stritzinger, M. Tomasella, L. Chen, Ping Harmanen, J. Hozzeinzadeh, G. Howell, D. Andrew Inserra, C. Nicholl, M. Nielsen, M. Smith, K. Somero, A. Tronsgaard, R. Young, D. R. |
| Affiliation | Univ Turku, Dept Phys & Astron, Tuorla Observ, FI-20014 Turku, Finland Univ Coll Dublin, OBrien Ctr Sci North, Sch Phys, Dublin 4, Ireland Stockholm Univ, Oskar Klein Ctr, Dept Astron, AlbaNova, S-10691 Stockholm, Sweden Univ Chile, UMI 3386, Unidad Mixta Int Franco Chilena Astron, Dept Astron,CNRS, Camino Observ 1515, Santiago 7591245, Chile Peking Univ, Kavli Inst Astron & Astrophys, Yi He Lean Rd 5, Beijing 100871, Peoples R China CSIC, Inst Space Sci, ICE, Campus UAB,Carrer Can Magrans S-N, E-08193 Barcelona, Spain IEEC, C Gran Capit 2-4,Edif Nexus 201, E-08034 Barcelona, Spain Univ Granada, Dept Fis Teor & Cosmos, E-18071 Granada, Spain Univ Southampton, Dept Phys & Astron, Southampton SO17 1BJ, Hants, England Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA Univ Turku, Finnish Ctr Astron ESO FINCA, FI-20014 Turku, Finland INAF Osservatorio Astron Padova, Vicolo Osservatorio 5, I-35122 Padua, Italy Univ Andres Bello, Dept Ciencias Fis, Avda Republ 252, Santiago 8370134, Chile Millennium Inst Astrophys MAS, Nuncio Monsenor Sotero Sanz 100, Santiago 8320000, Chile Queens Univ, Astrophys Res Ctr, Sch Math & Phys, Belfast BT7 1NN, Antrim, North Ireland Aarhus Univ, Dept Phys & Astron, Ny Munkegade 120, DK-8000 Aarhus C, Denmark Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA Las Cumbres Observ, 6740 Cortona Dr Ste 102, Goleta, CA 93117 USA Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93106 USA Cardiff Univ, Sch Phys & Astron, Queens Bldg, Cardiff CF24 3AA, Wales Univ Edinburgh, Inst Astron, Royal Observ, Blackford Hill, Edinburgh EH9 3HJ, Midlothian, Scotland Tech Univ Denmark, Natl Space Inst, DTU Space, Elektrovej 328, DK-2800 Lyngby, Denmark |
| Keywords | HUBBLE-SPACE-TELESCOPE LIGHT CURVES MASSIVE STARS CIRCUMSTELLAR INTERACTION INTERACTING SUPERNOVAE RADIATIVE-TRANSFER NOVA 1979C LATE TIMES X-RAY EMISSION |
| Issue Date | Apr-2020 |
| Publisher | MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY |
| Abstract | We present observations of the unusually luminous Type II supernova (SN) 2016gsd. With a peak absolute magnitude of V = -19.95 +/- 0.08, this object is one of the brightest Type II SNe, and lies in the gap of magnitudes between the majority of Type II SNe and the superluminous SNe. Its light curve shows little evidence of the expected drop from the optically thick phase to the radioactively powered tail. The velocities derived from the absorption in( )H alpha are also unusually high with the blue edge tracing the fastest moving gas initially at 20 000 km s(-1), and then declining approximately linearly to 15000 km s(-1) over similar to 100 d. The dwarf host galaxy of the SN indicates a low-metallicity progenitor which may also contribute to the weakness of the metal lines in its spectra. We examine SN 2016gsd with reference to similarly luminous, linear Type II SNe such as SNe 1979C and 1998S, and discuss the interpretation of its observational characteristics. We compare the observations with a model produced by the JEKYLL code and find that a massive star with a depleted and inflated hydrogen envelope struggles to reproduce the high luminosity and extreme linearity of SN 2016gsd. Instead, we suggest that the influence of interaction between the SN ejecta and circumstellar material can explain the majority of the observed properties of the SN. The high velocities and strong H alpha absorption present throughout the evolution of the SN may imply a circumstellar medium configured in an asymmetric geometry. |
| URI | http://hdl.handle.net/20.500.11897/587982 |
| ISSN | 0035-8711 |
| DOI | 10.1093/mnras/staa365 |
| Indexed | SCI(E) |
| Appears in Collections: | 科维理天文与天体物理研究所 |
