_version_ 1866913708494553088
author Ni, Yuan Qi
Moon, Dae-Sik
Drout, Maria R.
Polin, Abigail
Sand, David J.
GonzÁlez-GaitÁn, Santiago
Kim, Sang Chul
Lee, Youngdae
Park, Hong Soo
Howell, D. Andrew
Nugent, Peter E.
Piro, Anthony L.
Brown, Peter J.
Galbany, LluÍs
Burke, Jamison
Hiramatsu, Daichi
Hosseinzadeh, Griffin
Valenti, Stefano
Afsariardchi, Niloufar
Andrews, Jennifer E.
Antoniadis, John
Beaton, Rachael L.
Bostroem, K. Azalee
Carlberg, Raymond G.
Cenko, S. Bradley
Cha, Sang-Mok
Dong, Yize
Gal-Yam, Avishay
Haislip, Joshua
Holoien, Thomas W. -S.
Johnson, Sean D.
Kouprianov, Vladimir
Lee, Yongseok
Matzner, Christopher D.
Morrell, Nidia
Mccully, Curtis
Pignata, Giuliano
Reichart, Daniel E.
Rich, Jeffrey
Ryder, Stuart D.
Smith, Nathan
Wyatt, Samuel
Yang, Sheng
author_facet Ni, Yuan Qi
Moon, Dae-Sik
Drout, Maria R.
Polin, Abigail
Sand, David J.
GonzÁlez-GaitÁn, Santiago
Kim, Sang Chul
Lee, Youngdae
Park, Hong Soo
Howell, D. Andrew
Nugent, Peter E.
Piro, Anthony L.
Brown, Peter J.
Galbany, LluÍs
Burke, Jamison
Hiramatsu, Daichi
Hosseinzadeh, Griffin
Valenti, Stefano
Afsariardchi, Niloufar
Andrews, Jennifer E.
Antoniadis, John
Beaton, Rachael L.
Bostroem, K. Azalee
Carlberg, Raymond G.
Cenko, S. Bradley
Cha, Sang-Mok
Dong, Yize
Gal-Yam, Avishay
Haislip, Joshua
Holoien, Thomas W. -S.
Johnson, Sean D.
Kouprianov, Vladimir
Lee, Yongseok
Matzner, Christopher D.
Morrell, Nidia
Mccully, Curtis
Pignata, Giuliano
Reichart, Daniel E.
Rich, Jeffrey
Ryder, Stuart D.
Smith, Nathan
Wyatt, Samuel
Yang, Sheng
contents SN~2018aoz is a Type Ia SN with a $B$-band plateau and excess emission in the infant-phase light curves $\lesssim$ 1 day after first light, evidencing an over-density of surface iron-peak elements as shown in our previous study. Here, we advance the constraints on the nature and origin of SN~2018aoz based on its evolution until the nebular phase. Near-peak spectroscopic features show the SN is intermediate between two subtypes of normal Type Ia: Core-Normal and Broad-Line. The excess emission could have contributions from the radioactive decay of surface iron-peak elements as well as ejecta interaction with either the binary companion or a small torus of circumstellar material. Nebular-phase limits on H$α$ and He~I favour a white dwarf companion, consistent with the small companion size constrained by the low early SN luminosity, while the absence of [O~I] and He~I disfavours a violent merger of the progenitor. Of the two main explosion mechanisms proposed to explain the distribution of surface iron-peak elements in SN~2018aoz, the asymmetric Chandrasekhar-mass explosion is less consistent with the progenitor constraints and the observed blueshifts of nebular-phase [Fe~II] and [Ni~II]. The helium-shell double-detonation explosion is compatible with the observed lack of C spectral features, but current 1-D models are incompatible with the infant-phase excess emission, $B_{\rm max}-V_{\rm max}$ color, and absence of nebular-phase [Ca~II]. Although the explosion processes of SN~2018aoz still need to be more precisely understood, the same processes could produce a significant fraction of Type Ia SNe that appear normal after $\sim$ 1 day.
format Preprint
id arxiv_https___arxiv_org_abs_2206_12437
institution arXiv
publishDate 2022
record_format arxiv
spellingShingle The origin and evolution of the normal Type Ia SN 2018aoz with infant-phase reddening and excess emission
Ni, Yuan Qi
Moon, Dae-Sik
Drout, Maria R.
Polin, Abigail
Sand, David J.
GonzÁlez-GaitÁn, Santiago
Kim, Sang Chul
Lee, Youngdae
Park, Hong Soo
Howell, D. Andrew
Nugent, Peter E.
Piro, Anthony L.
Brown, Peter J.
Galbany, LluÍs
Burke, Jamison
Hiramatsu, Daichi
Hosseinzadeh, Griffin
Valenti, Stefano
Afsariardchi, Niloufar
Andrews, Jennifer E.
Antoniadis, John
Beaton, Rachael L.
Bostroem, K. Azalee
Carlberg, Raymond G.
Cenko, S. Bradley
Cha, Sang-Mok
Dong, Yize
Gal-Yam, Avishay
Haislip, Joshua
Holoien, Thomas W. -S.
Johnson, Sean D.
Kouprianov, Vladimir
Lee, Yongseok
Matzner, Christopher D.
Morrell, Nidia
Mccully, Curtis
Pignata, Giuliano
Reichart, Daniel E.
Rich, Jeffrey
Ryder, Stuart D.
Smith, Nathan
Wyatt, Samuel
Yang, Sheng
Solar and Stellar Astrophysics
High Energy Astrophysical Phenomena
High Energy Physics - Phenomenology
SN~2018aoz is a Type Ia SN with a $B$-band plateau and excess emission in the infant-phase light curves $\lesssim$ 1 day after first light, evidencing an over-density of surface iron-peak elements as shown in our previous study. Here, we advance the constraints on the nature and origin of SN~2018aoz based on its evolution until the nebular phase. Near-peak spectroscopic features show the SN is intermediate between two subtypes of normal Type Ia: Core-Normal and Broad-Line. The excess emission could have contributions from the radioactive decay of surface iron-peak elements as well as ejecta interaction with either the binary companion or a small torus of circumstellar material. Nebular-phase limits on H$α$ and He~I favour a white dwarf companion, consistent with the small companion size constrained by the low early SN luminosity, while the absence of [O~I] and He~I disfavours a violent merger of the progenitor. Of the two main explosion mechanisms proposed to explain the distribution of surface iron-peak elements in SN~2018aoz, the asymmetric Chandrasekhar-mass explosion is less consistent with the progenitor constraints and the observed blueshifts of nebular-phase [Fe~II] and [Ni~II]. The helium-shell double-detonation explosion is compatible with the observed lack of C spectral features, but current 1-D models are incompatible with the infant-phase excess emission, $B_{\rm max}-V_{\rm max}$ color, and absence of nebular-phase [Ca~II]. Although the explosion processes of SN~2018aoz still need to be more precisely understood, the same processes could produce a significant fraction of Type Ia SNe that appear normal after $\sim$ 1 day.
title The origin and evolution of the normal Type Ia SN 2018aoz with infant-phase reddening and excess emission
topic Solar and Stellar Astrophysics
High Energy Astrophysical Phenomena
High Energy Physics - Phenomenology
url https://arxiv.org/abs/2206.12437