_version_ 1866929372193095680
author Stritzinger, Maximilian D.
Baron, Eddie
Taddia, Francesco
Burns, Chris R.
Galbany, Morgan Fraserm Lluis
Holmbo, Simon
Hoeflich, Peter
Morrell, Nidia
Hsiao, E. Y.
Johansson, Joel P.
Karamehmetoglu, Emir
Kuncarayakti, Hanindyo
Lyman, Joe
Moriya, Takashi J.
Phan, Kim
Phillips, Mark M.
Anderson, Joseph P.
Ashall, Chris
Brown, Peter J.
Castellon, Sergio
Della Valle, Massimo
Gonzalez-Gaitan, Santiago
Gromadzki, Mariusz
Handberg, Rasmus
Lu, Jing
Nicholl, Matt
Shahbandeh, Melissa
author_facet Stritzinger, Maximilian D.
Baron, Eddie
Taddia, Francesco
Burns, Chris R.
Galbany, Morgan Fraserm Lluis
Holmbo, Simon
Hoeflich, Peter
Morrell, Nidia
Hsiao, E. Y.
Johansson, Joel P.
Karamehmetoglu, Emir
Kuncarayakti, Hanindyo
Lyman, Joe
Moriya, Takashi J.
Phan, Kim
Phillips, Mark M.
Anderson, Joseph P.
Ashall, Chris
Brown, Peter J.
Castellon, Sergio
Della Valle, Massimo
Gonzalez-Gaitan, Santiago
Gromadzki, Mariusz
Handberg, Rasmus
Lu, Jing
Nicholl, Matt
Shahbandeh, Melissa
contents We present a comprehensive data set of supernova (SN) 2016adj located within the central dust lane of Centaurus A. SN 2016adj is significantly reddened and after correcting the peak apparent $B$-band magnitude ($m_B = 17.48\pm0.05$) for Milky Way reddening and our inferred host-galaxy reddening parameters (i.e., $R_{V}^{host} = 5.7\pm0.7$ and $A_{V}^{host} = 6.3\pm0.2$), we estimate it reached a peak absolute magnitude of $M_B \sim -18$. Detailed inspection of the optical/NIR spectroscopic time-series reveals a carbon-rich SN Ic and not a SN Ib/IIb as previously suggested in the literature. The NIR spectra shows prevalent carbon-monoxide formation occurring already by +41 days past $B$-band maximum, which is $\approx 11$ days earlier than previously reported in the literature for this object. Interestingly around two months past maximum, the NIR spectrum of SN~2016adj begins to exhibit H features, with a +97~d medium resolution spectrum revealing both Paschen and Bracket lines with absorption minima of $\sim 2000$ km/s, full-width-half-maximum emission velocities of $\sim 1000$ km/s, and emission line ratios consistent with a dense emission region. We speculate these attributes are due to circumstellar interaction (CSI) between the rapidly expanding SN ejecta and a H-rich shell of material formed during the pre-SN phase. A bolometric light curve is constructed and a semi-analytical model fit suggests the supernova synthesized 0.5 solar masses of $^{56}$Ni and ejected 4.2 solar masses of material, though these values should be approached with caution given the large uncertainties associated with the adopted reddening parameters, possible CSI contamination, and known light echo emission. Finally, inspection of Hubble Space Telescope archival data yielded no progenitor detection.
format Preprint
id arxiv_https___arxiv_org_abs_2309_05031
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle The carbon-rich type Ic supernova 2016adj in the iconic dust lane of Centaurus A: signatures of interaction with circumstellar hydrogen?
Stritzinger, Maximilian D.
Baron, Eddie
Taddia, Francesco
Burns, Chris R.
Galbany, Morgan Fraserm Lluis
Holmbo, Simon
Hoeflich, Peter
Morrell, Nidia
Hsiao, E. Y.
Johansson, Joel P.
Karamehmetoglu, Emir
Kuncarayakti, Hanindyo
Lyman, Joe
Moriya, Takashi J.
Phan, Kim
Phillips, Mark M.
Anderson, Joseph P.
Ashall, Chris
Brown, Peter J.
Castellon, Sergio
Della Valle, Massimo
Gonzalez-Gaitan, Santiago
Gromadzki, Mariusz
Handberg, Rasmus
Lu, Jing
Nicholl, Matt
Shahbandeh, Melissa
High Energy Astrophysical Phenomena
We present a comprehensive data set of supernova (SN) 2016adj located within the central dust lane of Centaurus A. SN 2016adj is significantly reddened and after correcting the peak apparent $B$-band magnitude ($m_B = 17.48\pm0.05$) for Milky Way reddening and our inferred host-galaxy reddening parameters (i.e., $R_{V}^{host} = 5.7\pm0.7$ and $A_{V}^{host} = 6.3\pm0.2$), we estimate it reached a peak absolute magnitude of $M_B \sim -18$. Detailed inspection of the optical/NIR spectroscopic time-series reveals a carbon-rich SN Ic and not a SN Ib/IIb as previously suggested in the literature. The NIR spectra shows prevalent carbon-monoxide formation occurring already by +41 days past $B$-band maximum, which is $\approx 11$ days earlier than previously reported in the literature for this object. Interestingly around two months past maximum, the NIR spectrum of SN~2016adj begins to exhibit H features, with a +97~d medium resolution spectrum revealing both Paschen and Bracket lines with absorption minima of $\sim 2000$ km/s, full-width-half-maximum emission velocities of $\sim 1000$ km/s, and emission line ratios consistent with a dense emission region. We speculate these attributes are due to circumstellar interaction (CSI) between the rapidly expanding SN ejecta and a H-rich shell of material formed during the pre-SN phase. A bolometric light curve is constructed and a semi-analytical model fit suggests the supernova synthesized 0.5 solar masses of $^{56}$Ni and ejected 4.2 solar masses of material, though these values should be approached with caution given the large uncertainties associated with the adopted reddening parameters, possible CSI contamination, and known light echo emission. Finally, inspection of Hubble Space Telescope archival data yielded no progenitor detection.
title The carbon-rich type Ic supernova 2016adj in the iconic dust lane of Centaurus A: signatures of interaction with circumstellar hydrogen?
topic High Energy Astrophysical Phenomena
url https://arxiv.org/abs/2309.05031