TY - JOUR
T1 - KSP-SN-2016kf
T2 - A Long-rising H-rich Type II Supernova with Unusually High 56Ni Mass Discovered in the KMTNet Supernova Program
AU - Afsariardchi, Niloufar
AU - Moon, Dae-Sik
AU - Drout, Maria R.
AU - Gonzalez-Gaitan, Santiago
AU - Ni, Yuan Qi
AU - Matzner, Christopher D.
AU - Kim, Sang Chul
AU - Lee, Youngdae
AU - Park, Hong Soo
AU - Gal-Yam, Avishay
AU - Pignata, Giuliano
AU - Koo, Bon-Chul
AU - Ryder, Stuart
AU - Cha, Sang-Mok
AU - Lee, Yongseok
N1 - This research has made use of the KMTNet facility operated by the Korea Astronomy and Space Science Institute and the data were obtained at three host sites of CTIO in Chile, SAAO in South Africa, and SSO in Australia. We acknowledge with thanks the variable-star observations from the AAVSO International Database contributed by observers worldwide and used in this research. Our simulations were carried out on Compute Canada resources. PyRAF is a product of the Space Telescope Science Institute, which is operated by AURA for NASA. N.A. was supported by QEII-GSST and OGS Fellowships. D.S.M. was supported in part by a Leading Edge Fund from the Canadian Foundation for Innovation (project No. 30951) and a Discovery Grant from the Natural Sciences and Engineering Research Council of Canada. Support for this work was provided to M.R.D. by NASA through Hubble Fellowship grant NSG-HF2-51373 awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555. M.R.D. acknowledges support from the Dunlap Institute at the University of Toronto. S.G.G. acknowledges the support from the Portuguese Strategic Programme UID/FIS/00099/2013 for CENTRA and the FCT project PTDC/FIS-AST/31546/2017. Support for G.P. is provided by the Ministry of Economy, Development, and Tourism's Millennium Science Initiative through grant IC120009, awarded to The Millennium Institute of Astrophysics, MAS. Finally, we thank the anonymous referee for helpful comments on the original draft of this work.
PY - 2019/8/8
Y1 - 2019/8/8
N2 - We present the discovery and the photometric and spectroscopic study of H-rich Type II supernova (SN) KSP-SN-2016kf (SN2017it) observed in the KMTNet Supernova Program in the outskirts of a small irregular galaxy at z ≃ 0.043 within a day of the explosion. Our high-cadence, multi-color (BVI) light curves of the SN show that it has a very long rise time (t rise ≃ 20 days in the V band), a moderately luminous peak (M V ≃ -17.6 mag), a notably luminous and flat plateau (M V ≃ -17.4 mag and decay slope s ≃ 0.53 mag per 100 days), and an exceptionally bright radioactive tail. Using the color-dependent bolometric correction to the light curves, we estimate the 56Ni mass powering the observed radioactive tail to be 0.10 ±0.01 M , making it an H-rich Type II SN with one of the largest 56Ni masses observed to date. The results of our hydrodynamic simulations of the light curves constrain the mass and radius of the progenitor at the explosion to be ∼15 M (evolved from a star with an initial mass of ∼18.8 M ) and ∼1040 R , respectively, with the SN explosion energy of ∼1.3 ×10 51 erg. The above-average mass of the KSP-SN-2016kf progenitor, together with its low metallicity of obtained from spectroscopic analysis, is indicative of a link between the explosion of high-mass red supergiants and their low-metallicity environment. The early part of the observed light curves shows the presence of excess emission above what is predicted in model calculations, suggesting there is interaction between the ejecta and circumstellar material. We further discuss the implications of the high initial mass of the progenitor and the low-metallicity environment of KSP-SN-2016kf for our understanding of the origin of Type II SNe.
AB - We present the discovery and the photometric and spectroscopic study of H-rich Type II supernova (SN) KSP-SN-2016kf (SN2017it) observed in the KMTNet Supernova Program in the outskirts of a small irregular galaxy at z ≃ 0.043 within a day of the explosion. Our high-cadence, multi-color (BVI) light curves of the SN show that it has a very long rise time (t rise ≃ 20 days in the V band), a moderately luminous peak (M V ≃ -17.6 mag), a notably luminous and flat plateau (M V ≃ -17.4 mag and decay slope s ≃ 0.53 mag per 100 days), and an exceptionally bright radioactive tail. Using the color-dependent bolometric correction to the light curves, we estimate the 56Ni mass powering the observed radioactive tail to be 0.10 ±0.01 M , making it an H-rich Type II SN with one of the largest 56Ni masses observed to date. The results of our hydrodynamic simulations of the light curves constrain the mass and radius of the progenitor at the explosion to be ∼15 M (evolved from a star with an initial mass of ∼18.8 M ) and ∼1040 R , respectively, with the SN explosion energy of ∼1.3 ×10 51 erg. The above-average mass of the KSP-SN-2016kf progenitor, together with its low metallicity of obtained from spectroscopic analysis, is indicative of a link between the explosion of high-mass red supergiants and their low-metallicity environment. The early part of the observed light curves shows the presence of excess emission above what is predicted in model calculations, suggesting there is interaction between the ejecta and circumstellar material. We further discuss the implications of the high initial mass of the progenitor and the low-metallicity environment of KSP-SN-2016kf for our understanding of the origin of Type II SNe.
U2 - https://doi.org/10.3847/1538-4357/ab2be6
DO - https://doi.org/10.3847/1538-4357/ab2be6
M3 - مقالة
SN - 0004-637X
VL - 881
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1
M1 - 22
ER -