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Photometric and Spectroscopic Properties of Type Ia Supernova 2018oh with Early Excess Emission from the $Kepler$ 2 Observations

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Photometric and Spectroscopic Properties of Type Ia Supernova 2018oh with Early Excess Emission from the $Kepler$ 2 Observations. / Li, W.; Wang, X.; Vinkó, J.; Mo, J.; Hosseinzadeh, G.; Sand, D. J.; Zhang, J.; Lin, H.; Zhang, T.; Wang, L.; Zhang, J.; Chen, Z.; Xiang, D.; Rui, L.; Huang, F.; Li, X.; Zhang, X.; Li, L.; Baron, E.; Derkacy, J. M.; Zhao, X.; Sai, H.; Zhang, K.; Wang, L.; Howell, D. A.; McCully, C.; Arcavi, I.; Valenti, S.; Hiramatsu, D.; Burke, J.; Rest, A.; Garnavich, P.; Tucker, B. E.; Narayan, G.; Shaya, E.; Margheim, S.; Zenteno, A.; Villar, A.; Dimitriadis, G.; Foley, R. J.; Pan, Y.-C.; Coulter, D. A.; Fox, O. D.; Jha, S. W.; Jones, D. O.; Kasen, D. N.; Kilpatrick, C. D.; Piro, A. L.; Riess, A. G.; Rojas-Bravo, C.; Shappee, B. J.; Holoien, T. W.-S.; Stanek, K. Z.; Drout, M. R.; Auchettl, K.; Kochanek, C. S.; Brown, J. S.; Bose, S.; Bersier, D.; Brimacombe, J.; Chen, P.; Dong, S.; Holmbo, S.; Muñoz, J. A.; Mutel, R. L.; Post, R. S.; Prieto, J. L.; Shields, J.; Tallon, D.; Thompson, T. A.; Vallely, P. J.; Villanueva, S., Jr.; Smartt, S. J.; Smith, K. W.; Chambers, K. C.; Flewelling, H. A.; Huber, M. E.; Magnier, E. A.; Waters, C. Z.; Schultz, A. S. B.; Bulger, J.; Lowe, T. B.; Willman, M.; Sárneczky, K.; Pál, A.; Wheeler, J. C.; Bódi, A.; Bognár, Zs.; Csák, B.; Cseh, B.; Csörnyei, G.; Hanyecz, O.; Ignácz, B.; Kalup, Cs.; Könyves-Tóth, R.; Kriskovics, L.; Ordasi, A.; Rajmon, I.; Sódor, A.; Szabó, R.; Szakáts, R.; Zsidi, G.; Milne, P.; Andrews, J. E.; Smith, N.; Bilinski, C.; Brown, P. J.; Nordin, J.; Williams, S. C.; Galbany, L.; Palmerio, J.; Hook, I. M.; Inserra, C.; Maguire, K.; Cartier, Régis; Razza, A.; Gutiérrez, C. P.; Hermes, J. J.; Reding, J. S.; Kaiser, B. C.; Tonry, J. L.; Heinze, A. N.; Denneau, L.; Weiland, H.; Stalder, B.; Barentsen, G.; Dotson, J.; Barclay, T.; Gully-Santiago, M.; Hedges, C.; Cody, A. M.; Howell, S.; Coughlin, J.; Van Cleve, J. E.; Cardoso, J. Vinícius de Miranda; Larson, K. A.; McCalmont-Everton, K. M.; Peterson, C. A.; Ross, S. E.; Reedy, L. H.; Osborne, D.; McGinn, C.; Kohnert, L.; Migliorini, L.; Wheaton, A.; Spencer, B.; Labonde, C.; Castillo, G.; Beerman, G.; Steward, K.; Hanley, M.; Larsen, R.; Gangopadhyay, R.; Kloetzel, R.; Weschler, T.; Nystrom, V.; Moffatt, J.; Redick, M.; Griest, K.; Packard, M.; Muszynski, M.; Kampmeier, J.; Bjella, R.; Flynn, S.; Elsaesser, B.

In: The Astrophysical Journal, Vol. 870, No. 1, 12, 01.2019.

Research output: Contribution to journalJournal articlepeer-review

Harvard

Li, W, Wang, X, Vinkó, J, Mo, J, Hosseinzadeh, G, Sand, DJ, Zhang, J, Lin, H, Zhang, T, Wang, L, Zhang, J, Chen, Z, Xiang, D, Rui, L, Huang, F, Li, X, Zhang, X, Li, L, Baron, E, Derkacy, JM, Zhao, X, Sai, H, Zhang, K, Wang, L, Howell, DA, McCully, C, Arcavi, I, Valenti, S, Hiramatsu, D, Burke, J, Rest, A, Garnavich, P, Tucker, BE, Narayan, G, Shaya, E, Margheim, S, Zenteno, A, Villar, A, Dimitriadis, G, Foley, RJ, Pan, Y-C, Coulter, DA, Fox, OD, Jha, SW, Jones, DO, Kasen, DN, Kilpatrick, CD, Piro, AL, Riess, AG, Rojas-Bravo, C, Shappee, BJ, Holoien, TW-S, Stanek, KZ, Drout, MR, Auchettl, K, Kochanek, CS, Brown, JS, Bose, S, Bersier, D, Brimacombe, J, Chen, P, Dong, S, Holmbo, S, Muñoz, JA, Mutel, RL, Post, RS, Prieto, JL, Shields, J, Tallon, D, Thompson, TA, Vallely, PJ, Villanueva, SJ, Smartt, SJ, Smith, KW, Chambers, KC, Flewelling, HA, Huber, ME, Magnier, EA, Waters, CZ, Schultz, ASB, Bulger, J, Lowe, TB, Willman, M, Sárneczky, K, Pál, A, Wheeler, JC, Bódi, A, Bognár, Z, Csák, B, Cseh, B, Csörnyei, G, Hanyecz, O, Ignácz, B, Kalup, C, Könyves-Tóth, R, Kriskovics, L, Ordasi, A, Rajmon, I, Sódor, A, Szabó, R, Szakáts, R, Zsidi, G, Milne, P, Andrews, JE, Smith, N, Bilinski, C, Brown, PJ, Nordin, J, Williams, SC, Galbany, L, Palmerio, J, Hook, IM, Inserra, C, Maguire, K, Cartier, R, Razza, A, Gutiérrez, CP, Hermes, JJ, Reding, JS, Kaiser, BC, Tonry, JL, Heinze, AN, Denneau, L, Weiland, H, Stalder, B, Barentsen, G, Dotson, J, Barclay, T, Gully-Santiago, M, Hedges, C, Cody, AM, Howell, S, Coughlin, J, Van Cleve, JE, Cardoso, JVDM, Larson, KA, McCalmont-Everton, KM, Peterson, CA, Ross, SE, Reedy, LH, Osborne, D, McGinn, C, Kohnert, L, Migliorini, L, Wheaton, A, Spencer, B, Labonde, C, Castillo, G, Beerman, G, Steward, K, Hanley, M, Larsen, R, Gangopadhyay, R, Kloetzel, R, Weschler, T, Nystrom, V, Moffatt, J, Redick, M, Griest, K, Packard, M, Muszynski, M, Kampmeier, J, Bjella, R, Flynn, S & Elsaesser, B 2019, 'Photometric and Spectroscopic Properties of Type Ia Supernova 2018oh with Early Excess Emission from the $Kepler$ 2 Observations', The Astrophysical Journal, vol. 870, no. 1, 12. https://doi.org/10.3847/1538-4357/aaec74

APA

Li, W., Wang, X., Vinkó, J., Mo, J., Hosseinzadeh, G., Sand, D. J., Zhang, J., Lin, H., Zhang, T., Wang, L., Zhang, J., Chen, Z., Xiang, D., Rui, L., Huang, F., Li, X., Zhang, X., Li, L., Baron, E., ... Elsaesser, B. (2019). Photometric and Spectroscopic Properties of Type Ia Supernova 2018oh with Early Excess Emission from the $Kepler$ 2 Observations. The Astrophysical Journal, 870(1), [12]. https://doi.org/10.3847/1538-4357/aaec74

Vancouver

Author

Li, W. ; Wang, X. ; Vinkó, J. ; Mo, J. ; Hosseinzadeh, G. ; Sand, D. J. ; Zhang, J. ; Lin, H. ; Zhang, T. ; Wang, L. ; Zhang, J. ; Chen, Z. ; Xiang, D. ; Rui, L. ; Huang, F. ; Li, X. ; Zhang, X. ; Li, L. ; Baron, E. ; Derkacy, J. M. ; Zhao, X. ; Sai, H. ; Zhang, K. ; Wang, L. ; Howell, D. A. ; McCully, C. ; Arcavi, I. ; Valenti, S. ; Hiramatsu, D. ; Burke, J. ; Rest, A. ; Garnavich, P. ; Tucker, B. E. ; Narayan, G. ; Shaya, E. ; Margheim, S. ; Zenteno, A. ; Villar, A. ; Dimitriadis, G. ; Foley, R. J. ; Pan, Y.-C. ; Coulter, D. A. ; Fox, O. D. ; Jha, S. W. ; Jones, D. O. ; Kasen, D. N. ; Kilpatrick, C. D. ; Piro, A. L. ; Riess, A. G. ; Rojas-Bravo, C. ; Shappee, B. J. ; Holoien, T. W.-S. ; Stanek, K. Z. ; Drout, M. R. ; Auchettl, K. ; Kochanek, C. S. ; Brown, J. S. ; Bose, S. ; Bersier, D. ; Brimacombe, J. ; Chen, P. ; Dong, S. ; Holmbo, S. ; Muñoz, J. A. ; Mutel, R. L. ; Post, R. S. ; Prieto, J. L. ; Shields, J. ; Tallon, D. ; Thompson, T. A. ; Vallely, P. J. ; Villanueva, S., Jr. ; Smartt, S. J. ; Smith, K. W. ; Chambers, K. C. ; Flewelling, H. A. ; Huber, M. E. ; Magnier, E. A. ; Waters, C. Z. ; Schultz, A. S. B. ; Bulger, J. ; Lowe, T. B. ; Willman, M. ; Sárneczky, K. ; Pál, A. ; Wheeler, J. C. ; Bódi, A. ; Bognár, Zs. ; Csák, B. ; Cseh, B. ; Csörnyei, G. ; Hanyecz, O. ; Ignácz, B. ; Kalup, Cs. ; Könyves-Tóth, R. ; Kriskovics, L. ; Ordasi, A. ; Rajmon, I. ; Sódor, A. ; Szabó, R. ; Szakáts, R. ; Zsidi, G. ; Milne, P. ; Andrews, J. E. ; Smith, N. ; Bilinski, C. ; Brown, P. J. ; Nordin, J. ; Williams, S. C. ; Galbany, L. ; Palmerio, J. ; Hook, I. M. ; Inserra, C. ; Maguire, K. ; Cartier, Régis ; Razza, A. ; Gutiérrez, C. P. ; Hermes, J. J. ; Reding, J. S. ; Kaiser, B. C. ; Tonry, J. L. ; Heinze, A. N. ; Denneau, L. ; Weiland, H. ; Stalder, B. ; Barentsen, G. ; Dotson, J. ; Barclay, T. ; Gully-Santiago, M. ; Hedges, C. ; Cody, A. M. ; Howell, S. ; Coughlin, J. ; Van Cleve, J. E. ; Cardoso, J. Vinícius de Miranda ; Larson, K. A. ; McCalmont-Everton, K. M. ; Peterson, C. A. ; Ross, S. E. ; Reedy, L. H. ; Osborne, D. ; McGinn, C. ; Kohnert, L. ; Migliorini, L. ; Wheaton, A. ; Spencer, B. ; Labonde, C. ; Castillo, G. ; Beerman, G. ; Steward, K. ; Hanley, M. ; Larsen, R. ; Gangopadhyay, R. ; Kloetzel, R. ; Weschler, T. ; Nystrom, V. ; Moffatt, J. ; Redick, M. ; Griest, K. ; Packard, M. ; Muszynski, M. ; Kampmeier, J. ; Bjella, R. ; Flynn, S. ; Elsaesser, B. / Photometric and Spectroscopic Properties of Type Ia Supernova 2018oh with Early Excess Emission from the $Kepler$ 2 Observations. In: The Astrophysical Journal. 2019 ; Vol. 870, No. 1.

Bibtex

@article{4e649eeb9b1e49ad825bc738546ed3e2,
title = "Photometric and Spectroscopic Properties of Type Ia Supernova 2018oh with Early Excess Emission from the $Kepler$ 2 Observations",
abstract = "Supernova (SN) 2018oh (ASASSN-18bt) is the first spectroscopically-confirmed type Ia supernova (SN Ia) observed in the $Kepler$ field. The $Kepler$ data revealed an excess emission in its early light curve, allowing to place interesting constraints on its progenitor system (Dimitriadis et al. 2018, Shappee et al. 2018b). Here, we present extensive optical, ultraviolet, and near-infrared photometry, as well as dense sampling of optical spectra, for this object. SN 2018oh is relatively normal in its photometric evolution, with a rise time of 18.3$\pm$0.3 days and $\Delta$m$_{15}(B)=0.96\pm$0.03 mag, but it seems to have bluer $B - V$ colors. We construct the {"}uvoir{"} bolometric light curve having peak luminosity as 1.49$\times$10$^{43}$erg s$^{-1}$, from which we derive a nickel mass as 0.55$\pm$0.04M$_{\odot}$ by fitting radiation diffusion models powered by centrally located $^{56}$Ni. Note that the moment when nickel-powered luminosity starts to emerge is +3.85 days after the first light in the Kepler data, suggesting other origins of the early-time emission, e.g., mixing of $^{56}$Ni to outer layers of the ejecta or interaction between the ejecta and nearby circumstellar material or a non-degenerate companion star. The spectral evolution of SN 2018oh is similar to that of a normal SN Ia, but is characterized by prominent and persistent carbon absorption features. The C II features can be detected from the early phases to about 3 weeks after the maximum light, representing the latest detection of carbon ever recorded in a SN Ia. This indicates that a considerable amount of unburned carbon exists in the ejecta of SN 2018oh and may mix into deeper layers.",
keywords = "Astrophysics - Solar and Stellar Astrophysics, Astrophysics - High Energy Astrophysical Phenomena",
author = "W. Li and X. Wang and J. Vink{\'o} and J. Mo and G. Hosseinzadeh and Sand, {D. J.} and J. Zhang and H. Lin and T. Zhang and L. Wang and J. Zhang and Z. Chen and D. Xiang and L. Rui and F. Huang and X. Li and X. Zhang and L. Li and E. Baron and Derkacy, {J. M.} and X. Zhao and H. Sai and K. Zhang and L. Wang and Howell, {D. A.} and C. McCully and I. Arcavi and S. Valenti and D. Hiramatsu and J. Burke and A. Rest and P. Garnavich and Tucker, {B. E.} and G. Narayan and E. Shaya and S. Margheim and A. Zenteno and A. Villar and G. Dimitriadis and Foley, {R. J.} and Y.-C. Pan and Coulter, {D. A.} and Fox, {O. D.} and Jha, {S. W.} and Jones, {D. O.} and Kasen, {D. N.} and Kilpatrick, {C. D.} and Piro, {A. L.} and Riess, {A. G.} and C. Rojas-Bravo and Shappee, {B. J.} and Holoien, {T. W.-S.} and Stanek, {K. Z.} and Drout, {M. R.} and K. Auchettl and Kochanek, {C. S.} and Brown, {J. S.} and S. Bose and D. Bersier and J. Brimacombe and P. Chen and S. Dong and S. Holmbo and Mu{\~n}oz, {J. A.} and Mutel, {R. L.} and Post, {R. S.} and Prieto, {J. L.} and J. Shields and D. Tallon and Thompson, {T. A.} and Vallely, {P. J.} and Villanueva, {S., Jr.} and Smartt, {S. J.} and Smith, {K. W.} and Chambers, {K. C.} and Flewelling, {H. A.} and Huber, {M. E.} and Magnier, {E. A.} and Waters, {C. Z.} and Schultz, {A. S. B.} and J. Bulger and Lowe, {T. B.} and M. Willman and K. S{\'a}rneczky and A. P{\'a}l and Wheeler, {J. C.} and A. B{\'o}di and Zs. Bogn{\'a}r and B. Cs{\'a}k and B. Cseh and G. Cs{\"o}rnyei and O. Hanyecz and B. Ign{\'a}cz and Cs. Kalup and R. K{\"o}nyves-T{\'o}th and L. Kriskovics and A. Ordasi and I. Rajmon and A. S{\'o}dor and R. Szab{\'o} and R. Szak{\'a}ts and G. Zsidi and P. Milne and Andrews, {J. E.} and N. Smith and C. Bilinski and Brown, {P. J.} and J. Nordin and Williams, {S. C.} and L. Galbany and J. Palmerio and Hook, {I. M.} and C. Inserra and K. Maguire and R{\'e}gis Cartier and A. Razza and Guti{\'e}rrez, {C. P.} and Hermes, {J. J.} and Reding, {J. S.} and Kaiser, {B. C.} and Tonry, {J. L.} and Heinze, {A. N.} and L. Denneau and H. Weiland and B. Stalder and G. Barentsen and J. Dotson and T. Barclay and M. Gully-Santiago and C. Hedges and Cody, {A. M.} and S. Howell and J. Coughlin and {Van Cleve}, {J. E.} and Cardoso, {J. Vin{\'i}cius de Miranda} and Larson, {K. A.} and McCalmont-Everton, {K. M.} and Peterson, {C. A.} and Ross, {S. E.} and Reedy, {L. H.} and D. Osborne and C. McGinn and L. Kohnert and L. Migliorini and A. Wheaton and B. Spencer and C. Labonde and G. Castillo and G. Beerman and K. Steward and M. Hanley and R. Larsen and R. Gangopadhyay and R. Kloetzel and T. Weschler and V. Nystrom and J. Moffatt and M. Redick and K. Griest and M. Packard and M. Muszynski and J. Kampmeier and R. Bjella and S. Flynn and B. Elsaesser",
year = "2019",
month = jan,
doi = "10.3847/1538-4357/aaec74",
language = "English",
volume = "870",
journal = "The Astrophysical Journal",
issn = "0004-637X",
publisher = "Institute of Physics Publishing",
number = "1",

}

RIS

TY - JOUR

T1 - Photometric and Spectroscopic Properties of Type Ia Supernova 2018oh with Early Excess Emission from the $Kepler$ 2 Observations

AU - Li, W.

AU - Wang, X.

AU - Vinkó, J.

AU - Mo, J.

AU - Hosseinzadeh, G.

AU - Sand, D. J.

AU - Zhang, J.

AU - Lin, H.

AU - Zhang, T.

AU - Wang, L.

AU - Zhang, J.

AU - Chen, Z.

AU - Xiang, D.

AU - Rui, L.

AU - Huang, F.

AU - Li, X.

AU - Zhang, X.

AU - Li, L.

AU - Baron, E.

AU - Derkacy, J. M.

AU - Zhao, X.

AU - Sai, H.

AU - Zhang, K.

AU - Wang, L.

AU - Howell, D. A.

AU - McCully, C.

AU - Arcavi, I.

AU - Valenti, S.

AU - Hiramatsu, D.

AU - Burke, J.

AU - Rest, A.

AU - Garnavich, P.

AU - Tucker, B. E.

AU - Narayan, G.

AU - Shaya, E.

AU - Margheim, S.

AU - Zenteno, A.

AU - Villar, A.

AU - Dimitriadis, G.

AU - Foley, R. J.

AU - Pan, Y.-C.

AU - Coulter, D. A.

AU - Fox, O. D.

AU - Jha, S. W.

AU - Jones, D. O.

AU - Kasen, D. N.

AU - Kilpatrick, C. D.

AU - Piro, A. L.

AU - Riess, A. G.

AU - Rojas-Bravo, C.

AU - Shappee, B. J.

AU - Holoien, T. W.-S.

AU - Stanek, K. Z.

AU - Drout, M. R.

AU - Auchettl, K.

AU - Kochanek, C. S.

AU - Brown, J. S.

AU - Bose, S.

AU - Bersier, D.

AU - Brimacombe, J.

AU - Chen, P.

AU - Dong, S.

AU - Holmbo, S.

AU - Muñoz, J. A.

AU - Mutel, R. L.

AU - Post, R. S.

AU - Prieto, J. L.

AU - Shields, J.

AU - Tallon, D.

AU - Thompson, T. A.

AU - Vallely, P. J.

AU - Villanueva, S., Jr.

AU - Smartt, S. J.

AU - Smith, K. W.

AU - Chambers, K. C.

AU - Flewelling, H. A.

AU - Huber, M. E.

AU - Magnier, E. A.

AU - Waters, C. Z.

AU - Schultz, A. S. B.

AU - Bulger, J.

AU - Lowe, T. B.

AU - Willman, M.

AU - Sárneczky, K.

AU - Pál, A.

AU - Wheeler, J. C.

AU - Bódi, A.

AU - Bognár, Zs.

AU - Csák, B.

AU - Cseh, B.

AU - Csörnyei, G.

AU - Hanyecz, O.

AU - Ignácz, B.

AU - Kalup, Cs.

AU - Könyves-Tóth, R.

AU - Kriskovics, L.

AU - Ordasi, A.

AU - Rajmon, I.

AU - Sódor, A.

AU - Szabó, R.

AU - Szakáts, R.

AU - Zsidi, G.

AU - Milne, P.

AU - Andrews, J. E.

AU - Smith, N.

AU - Bilinski, C.

AU - Brown, P. J.

AU - Nordin, J.

AU - Williams, S. C.

AU - Galbany, L.

AU - Palmerio, J.

AU - Hook, I. M.

AU - Inserra, C.

AU - Maguire, K.

AU - Cartier, Régis

AU - Razza, A.

AU - Gutiérrez, C. P.

AU - Hermes, J. J.

AU - Reding, J. S.

AU - Kaiser, B. C.

AU - Tonry, J. L.

AU - Heinze, A. N.

AU - Denneau, L.

AU - Weiland, H.

AU - Stalder, B.

AU - Barentsen, G.

AU - Dotson, J.

AU - Barclay, T.

AU - Gully-Santiago, M.

AU - Hedges, C.

AU - Cody, A. M.

AU - Howell, S.

AU - Coughlin, J.

AU - Van Cleve, J. E.

AU - Cardoso, J. Vinícius de Miranda

AU - Larson, K. A.

AU - McCalmont-Everton, K. M.

AU - Peterson, C. A.

AU - Ross, S. E.

AU - Reedy, L. H.

AU - Osborne, D.

AU - McGinn, C.

AU - Kohnert, L.

AU - Migliorini, L.

AU - Wheaton, A.

AU - Spencer, B.

AU - Labonde, C.

AU - Castillo, G.

AU - Beerman, G.

AU - Steward, K.

AU - Hanley, M.

AU - Larsen, R.

AU - Gangopadhyay, R.

AU - Kloetzel, R.

AU - Weschler, T.

AU - Nystrom, V.

AU - Moffatt, J.

AU - Redick, M.

AU - Griest, K.

AU - Packard, M.

AU - Muszynski, M.

AU - Kampmeier, J.

AU - Bjella, R.

AU - Flynn, S.

AU - Elsaesser, B.

PY - 2019/1

Y1 - 2019/1

N2 - Supernova (SN) 2018oh (ASASSN-18bt) is the first spectroscopically-confirmed type Ia supernova (SN Ia) observed in the $Kepler$ field. The $Kepler$ data revealed an excess emission in its early light curve, allowing to place interesting constraints on its progenitor system (Dimitriadis et al. 2018, Shappee et al. 2018b). Here, we present extensive optical, ultraviolet, and near-infrared photometry, as well as dense sampling of optical spectra, for this object. SN 2018oh is relatively normal in its photometric evolution, with a rise time of 18.3$\pm$0.3 days and $\Delta$m$_{15}(B)=0.96\pm$0.03 mag, but it seems to have bluer $B - V$ colors. We construct the "uvoir" bolometric light curve having peak luminosity as 1.49$\times$10$^{43}$erg s$^{-1}$, from which we derive a nickel mass as 0.55$\pm$0.04M$_{\odot}$ by fitting radiation diffusion models powered by centrally located $^{56}$Ni. Note that the moment when nickel-powered luminosity starts to emerge is +3.85 days after the first light in the Kepler data, suggesting other origins of the early-time emission, e.g., mixing of $^{56}$Ni to outer layers of the ejecta or interaction between the ejecta and nearby circumstellar material or a non-degenerate companion star. The spectral evolution of SN 2018oh is similar to that of a normal SN Ia, but is characterized by prominent and persistent carbon absorption features. The C II features can be detected from the early phases to about 3 weeks after the maximum light, representing the latest detection of carbon ever recorded in a SN Ia. This indicates that a considerable amount of unburned carbon exists in the ejecta of SN 2018oh and may mix into deeper layers.

AB - Supernova (SN) 2018oh (ASASSN-18bt) is the first spectroscopically-confirmed type Ia supernova (SN Ia) observed in the $Kepler$ field. The $Kepler$ data revealed an excess emission in its early light curve, allowing to place interesting constraints on its progenitor system (Dimitriadis et al. 2018, Shappee et al. 2018b). Here, we present extensive optical, ultraviolet, and near-infrared photometry, as well as dense sampling of optical spectra, for this object. SN 2018oh is relatively normal in its photometric evolution, with a rise time of 18.3$\pm$0.3 days and $\Delta$m$_{15}(B)=0.96\pm$0.03 mag, but it seems to have bluer $B - V$ colors. We construct the "uvoir" bolometric light curve having peak luminosity as 1.49$\times$10$^{43}$erg s$^{-1}$, from which we derive a nickel mass as 0.55$\pm$0.04M$_{\odot}$ by fitting radiation diffusion models powered by centrally located $^{56}$Ni. Note that the moment when nickel-powered luminosity starts to emerge is +3.85 days after the first light in the Kepler data, suggesting other origins of the early-time emission, e.g., mixing of $^{56}$Ni to outer layers of the ejecta or interaction between the ejecta and nearby circumstellar material or a non-degenerate companion star. The spectral evolution of SN 2018oh is similar to that of a normal SN Ia, but is characterized by prominent and persistent carbon absorption features. The C II features can be detected from the early phases to about 3 weeks after the maximum light, representing the latest detection of carbon ever recorded in a SN Ia. This indicates that a considerable amount of unburned carbon exists in the ejecta of SN 2018oh and may mix into deeper layers.

KW - Astrophysics - Solar and Stellar Astrophysics

KW - Astrophysics - High Energy Astrophysical Phenomena

U2 - 10.3847/1538-4357/aaec74

DO - 10.3847/1538-4357/aaec74

M3 - Journal article

VL - 870

JO - The Astrophysical Journal

JF - The Astrophysical Journal

SN - 0004-637X

IS - 1

M1 - 12

ER -