TY - JOUR
T1 - Measuring nickel masses in Type Ia supernovae using cobalt emission in nebular phase spectra
AU - Childress, Michael J.
AU - Hillier, D. John
AU - Seitenzahl, Ivo
AU - Sullivan, Mark
AU - Maguire, Kate
AU - Taubenberger, Stefan
AU - Scalzo, Richard
AU - Ruiter, Ashley
AU - Blagorodnova, Nadejda
AU - Camacho, Yssavo
AU - Castillo, Jayden
AU - Elias-Rosa, Nancy
AU - Fraser, Morgan
AU - Gal-Yam, Avishay
AU - Graham, Melissa
AU - Howell, D. Andrew
AU - Inserra, Cosimo
AU - Jha, Saurabh W.
AU - Kumar, Sahana
AU - Mazzali, Paolo A.
AU - McCully, Curtis
AU - Morales-Garoffolo, Antonia
AU - Pandya, Viraj
AU - Polshaw, Joe
AU - Schmidt, Brian
AU - Smartt, Stephen
AU - Smith, Ken W.
AU - Sollerman, Jesper
AU - Spyromilio, Jason
AU - Tucker, Brad
AU - Valenti, Stefano
AU - Walton, Nicholas
AU - Wolf, Christian
AU - Yaron, Ofer
AU - Young, D. R.
AU - Yuan, Fang
AU - Zhang, Bonnie
N1 - Australian Research Council Centre of Excellence for All-sky Astrophysics (CAASTRO) [CE110001020]; Australian Research Council [FL0992131]; 'The Dark Universe' of the German Research Foundation (DFG) [TRR33]; NASA [NNX14AB41G]; European Community; European Union [267251, 320360, 264895]; Royal Society; EU/FP7-ERC grant [615929]; EU/FP7 via ERC grant [307260]; Quantum Universe I-Core programme by the Israeli Committee for planning and budgeting; ISF; Minerva grant; Weizmann-UK 'making connections' programme; Kimmel award; ARCHES award; Spanish Ministerio de Economia y Competitividad (MINECO) [ESP2013-41268-R]; European Research Council under the European Union [291222]; STFC [ST/I001123/1, ST/L000709/1]; National Science Foundation [AST-0847157, PHY-1263280]; ESO [188.D-3003]; W. M. Keck Foundation; National Aeronautics and Space AdministrationThis research was conducted by the Australian Research Council Centre of Excellence for All-sky Astrophysics (CAASTRO), through project number CE110001020. BPS and IRS acknowledge support from the Australian Research Council Laureate Fellowship Grant FL0992131. ST acknowledges support by TRR33 'The Dark Universe' of the German Research Foundation (DFG). DJH acknowledges support from NASA theory grant NNX14AB41G. KM is supported by a Marie Curie Intra-European Fellowship, within the 7th European Community Framework Programme (FP7). NER acknowledges the support from the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement no. 267251 'Astronomy Fellowships in Italy' (AstroFIt). MF acknowledges support from the European Union FP7 programme through ERC grant number 320360. MS acknowledges support from the Royal Society and EU/FP7-ERC grant no. [615929]. AGY is supported by the EU/FP7 via ERC grant no. 307260, the Quantum Universe I-Core programme by the Israeli Committee for planning and budgeting and the ISF, by Minerva and ISF grants, by the Weizmann-UK 'making connections' programme, and by Kim This research was conducted by the Australian Research Council Centre of Excellence for All-sky Astrophysics (CAASTRO), through project number CE110001020. BPS and IRS acknowledge support from the Australian Research Council Laureate Fellowship Grant FL0992131. ST acknowledges support by TRR33 'The Dark Universe' of the German Research Foundation (DFG). DJH acknowledges support from NASA theory grant NNX14AB41G. KM is supported by a Marie Curie Intra-European Fellowship, within the 7th European Community Framework Programme (FP7). NER acknowledges the support from the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement no. 267251 'Astronomy Fellowships in Italy' (AstroFIt). MF acknowledges support from the European Union FP7 programme through ERC grant number 320360. MS acknowledges support from the Royal Society and EU/FP7-ERC grant no. [615929]. AGY is supported by the EU/FP7 via ERC grant no. 307260, the Quantum Universe I-Core programme by the Israeli Committee for planning and budgeting and the ISF, by Minerva and ISF grants, by the Weizmann-UK 'making connections' programme, and by Kimmel and ARCHES awards. AMG acknowledges financial support by the Spanish Ministerio de Economia y Competitividad (MINECO) grant ESP2013-41268-R. The research leading to these results has received funding from the European Union's Seventh Framework Programme [FP7/2007-2013] under grant agreement no. 264895. SJS acknowledges funding from the European Research Council under the European Union's Seventh Framework Programme (FP7/2007-2013)/ERC Grant agreement no. [291222] and STFC grants ST/I001123/1 and ST/L000709/1. SWJ and YC acknowledge support from the National Science Foundation through grants AST-0847157 and PHY-1263280, respectively.; Part of this research was conducted while John Hillier was a Distinguished Visitor at the Research School of Astronomy and Astrophysics at the Australian National University. This research is based on observation
PY - 2015/12/21
Y1 - 2015/12/21
N2 - The light curves of Type Ia supernovae (SNe Ia) are powered by the radioactive decay of 56Ni to 56Co at early times, and the decay of 56Co to 56Fe from ~60 d after explosion. We examine the evolution of the [Co III] λ5893 emission complex during the nebular phase for SNe Ia with multiple nebular spectra and show that the line flux follows the square of the mass of 56Co as a function of time. This result indicates both efficient local energy deposition from positrons produced in 56Co decay and long-term stability of the ionization state of the nebula. We compile SN Ia nebular spectra from the literature and present 21 new late-phase spectra of 7 SNe Ia, including SN 2014J. From these we measure the flux in the [Co III] λ5893 line and remove its well-behaved time dependence to infer the initial mass of 56Ni (MNi) produced in the explosion.We then examine 56Ni yields for different SN Ia ejected masses (Mej - calculated using the relation between light-curve width and ejected mass) and find that the 56Ni masses of SNe Ia fall into two regimes: for narrow light curves (low stretch s ~ 0.7-0.9),MNi is clustered near MNi ≈ 0.4 M⊙ and shows a shallow increase as Mej increases from ~1 to 1.4 M⊙; at high stretch, Mej clusters at the Chandrasekhar mass (1.4 M⊙) while MNi spans a broad range from 0.6 to 1.2 M⊙. This could constitute evidence for two distinct SN Ia explosion mechanisms.
AB - The light curves of Type Ia supernovae (SNe Ia) are powered by the radioactive decay of 56Ni to 56Co at early times, and the decay of 56Co to 56Fe from ~60 d after explosion. We examine the evolution of the [Co III] λ5893 emission complex during the nebular phase for SNe Ia with multiple nebular spectra and show that the line flux follows the square of the mass of 56Co as a function of time. This result indicates both efficient local energy deposition from positrons produced in 56Co decay and long-term stability of the ionization state of the nebula. We compile SN Ia nebular spectra from the literature and present 21 new late-phase spectra of 7 SNe Ia, including SN 2014J. From these we measure the flux in the [Co III] λ5893 line and remove its well-behaved time dependence to infer the initial mass of 56Ni (MNi) produced in the explosion.We then examine 56Ni yields for different SN Ia ejected masses (Mej - calculated using the relation between light-curve width and ejected mass) and find that the 56Ni masses of SNe Ia fall into two regimes: for narrow light curves (low stretch s ~ 0.7-0.9),MNi is clustered near MNi ≈ 0.4 M⊙ and shows a shallow increase as Mej increases from ~1 to 1.4 M⊙; at high stretch, Mej clusters at the Chandrasekhar mass (1.4 M⊙) while MNi spans a broad range from 0.6 to 1.2 M⊙. This could constitute evidence for two distinct SN Ia explosion mechanisms.
UR - http://www.scopus.com/inward/record.url?scp=84949257370&partnerID=8YFLogxK
U2 - https://doi.org/10.1093/mnras/stv2173
DO - https://doi.org/10.1093/mnras/stv2173
M3 - مقالة
SN - 0035-8711
VL - 454
SP - 3816
EP - 3842
JO - MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
JF - MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
IS - 4
ER -