Accepted Manuscript: Constraining the Progenitor System of the Type Ia Supernova 2021aefx
This content will become publicly available on July 1, 2023
Title: Constraining the Progenitor System of the Type Ia Supernova 2021aefx
Abstract We present high-cadence optical and ultraviolet light curves of the normal Type Ia supernova (SN) 2021aefx, which shows an early bump during the first two days of observation. This bump may be a signature of interaction between the exploding white dwarf and a nondegenerate binary companion, or it may be intrinsic to the white dwarf explosion mechanism. In the case of the former, the short duration of the bump implies a relatively compact main-sequence companion star, although this conclusion is viewing-angle dependent. Our best-fit companion-shocking and double-detonation models both overpredict the UV luminosity during the bump, and existing nickel-shell models do not match the strength and timescale of the bump. We also present nebular spectra of SN 2021aefx, which do not show the hydrogen or helium emission expected from a nondegenerate companion, as well as a radio nondetection that rules out all symbiotic progenitor systems and most accretion disk winds. Our analysis places strong but conflicting constraints on the progenitor of SN 2021aefx; no current model can explain all of our observations.
Hosseinzadeh, Griffin; Sand, David J.; Lundqvist, Peter; Andrews, Jennifer E.; Bostroem, K. Azalee; Dong, Yize; Janzen, Daryl; Jencson, Jacob E.; Lundquist, Michael; Meza Retamal, Nicolas E.; Pearson, Jeniveve; Valenti, Stefano; Wyatt, Samuel; Burke, Jamison; Howell, D. Andrew; McCully, Curtis; Newsome, Megan; Gonzalez, Estefania Padilla; Pellegrino, Craig; Terreran, Giacomomore » ; Kwok, Lindsey A.; Jha, Saurabh W.; Strader, Jay; Kundu, Esha; Ryder, Stuart D.; Haislip, Joshua; Kouprianov, Vladimir; Reichart, Daniel E. « less
The Astrophysical Journal Letters
Nebular-phase spectra of Type Ia supernovae from the Las Cumbres Observatory Global Supernova Project
https://doi.org/10.1093/mnras/stac192
Graham, M. L. ; Kennedy, T. D. ; Kumar, S. ; Amaro, R. C. ; Sand, D. J. ; Jha, S. W. ; Galbany, L. ; Vinko, J. ; Wheeler, J. C. ; Hsiao, E. Y. ; et al ( January 2022 , Monthly Notices of the Royal Astronomical Society)
The observed diversity in Type Ia supernovae (SNe Ia) – the thermonuclear explosions of carbon–oxygen white dwarf stars used as cosmological standard candles – is currently met with a variety of explosion models and progenitor scenarios. To help improve our understanding of whether and how often different models contribute to the occurrence of SNe Ia and their assorted properties, we present a comprehensive analysis of seven nearby SNe Ia. We obtained one to two epochs of optical spectra with Gemini Observatory during the nebular phase (>200 d past peak) for each of these events, all of which had time series of photometry and spectroscopy at early times (the first ∼8 weeks after explosion). We use the combination of early- and late-time observations to assess the predictions of various models for the explosion (e.g. double-detonation, off-centre detonation, stellar collisions), progenitor star (e.g. ejecta mass, metallicity), and binary companion (e.g. another white dwarf or a non-degenerate star). Overall, we find general consistency in our observations with spherically symmetric models for SN Ia explosions, and with scenarios in which the binary companion is another degenerate star. We also present an in-depth analysis of SN 2017fzw, a member of the subgroup of SNe Ia which appear to be transitional betweenmore »the subluminous '91bg-like' events and normal SNe Ia, and for which nebular-phase spectra are rare.
Physical Properties of the Host Galaxies of Ca-rich Transients
Dong, Yuxin ; Milisavljevic, Dan ; Leja, Joel ; Sarbadhicary, Sumit K. ; Nugent, Anya E. ; Margutti, Raffaella ; Jacobson-Galán, Wynn V. ; Polin, Abigail ; Banovetz, John ; Reynolds, Jack M. ; et al ( March 2022 , The Astrophysical Journal)
Calcium-rich (Ca-rich) transients are a new class of supernovae (SNe) that are known for their comparatively rapid evolution, modest peak luminosities, and strong nebular calcium emission lines. Currently, the progenitor systems of Ca-rich transients remain unknown. Although they exhibit spectroscopic properties not unlike core-collapse Type Ib/c SNe, nearly half are found in the outskirts of their host galaxies, which are predominantly elliptical, suggesting a closer connection to the older stellar populations of SNe Ia. In this paper, we present a compilation of publicly available multiwavelength observations of all known and/or suspected host galaxies of Ca-rich transients ranging from far-UV to IR, and use these data to characterize their stellar populations withprospector. We estimate several galaxy parameters including integrated star formation rate, stellar mass, metallicity, and age. For nine host galaxies, the observations are sensitive enough to obtain nonparametric star formation histories, from which we recover SN rates and estimate probabilities that the Ca-rich transients in each of these host galaxies originated from a core-collapse versus Type Ia-like explosion. Our work supports the notion that the population of Ca-rich transients do not come exclusively from core-collapse explosions, and must either be only from white dwarf stars or a mixed populationmore »of white dwarf stars with other channels, potentially including massive star explosions. Additional photometry and explosion site spectroscopy of larger samples of Ca-rich host galaxies will improve these estimates and better constrain the ratio of white dwarf versus massive star progenitors of Ca-rich transients.
SN 2018agk: A Prototypical Type Ia Supernova with a Smooth Power-law Rise in Kepler (K2)
https://doi.org/10.3847/1538-4357/ac2c84
Wang, Qinan ; Rest, Armin ; Zenati, Yossef ; Ridden-Harper, Ryan ; Dimitriadis, Georgios ; Narayan, Gautham ; Villar, V. Ashley ; Magee, Mark R. ; Foley, Ryan J. ; Shaya, Edward J. ; et al ( December 2021 , The Astrophysical Journal)
Abstract We present the 30 minutes cadence Kepler/K2 light curve of the Type Ia supernova (SN Ia) SN 2018agk, covering approximately one week before explosion, the full rise phase, and the decline until 40 days after peak. We additionally present ground-based observations in multiple bands within the same time range, including the 1 day cadence DECam observations within the first ∼5 days after the first light. The Kepler early light curve is fully consistent with a single power-law rise, without evidence of any bump feature. We compare SN 2018agk with a sample of other SNe Ia without early excess flux from the literature. We find that SNe Ia without excess flux have slowly evolving early colors in a narrow range ( g − i ≈ −0.20 ± 0.20 mag) within the first ∼10 days. On the other hand, among SNe Ia detected with excess, SN 2017cbv and SN 2018oh tend to be bluer, while iPTF16abc's evolution is similar to normal SNe Ia without excess in g − i . We further compare the Kepler light curve of SN 2018agk with companion-interaction models, and rule out the existence of a typical nondegenerate companion undergoing Roche lobe overflow at viewing angles smallermore »than 45°.« less
Constraining Type Iax supernova progenitor systems with stellar population age dating
https://doi.org/10.1093/mnras/staa294
Takaro, Tyler ; Foley, Ryan J ; McCully, Curtis ; Fong, Wen-fai ; Jha, Saurabh W ; Narayan, Gautham ; Rest, Armin ; Stritzinger, Maximilian ; McKinnon, Kevin ( March 2020 , Monthly Notices of the Royal Astronomical Society)
ABSTRACT Type Iax supernovae (SNe Iax) are the most common class of peculiar SNe. While they are thought to be thermonuclear white-dwarf (WD) SNe, SNe Iax are observationally similar to, but distinct from SNe Ia. Unlike SNe Ia, where roughly 30 per cent occur in early-type galaxies, only one SN Iax has been discovered in an early-type galaxy, suggesting a relatively short delay time and a distinct progenitor system. Furthermore, one SN Iax progenitor system has been detected in pre-explosion images with its properties consistent with either of two models: a short-lived (<100 Myr) progenitor system consisting of a WD primary and a He-star companion, or a singular Wolf–Rayet progenitor star. Using deep Hubble Space Telescope images of nine nearby SN Iax host galaxies, we measure the properties of stars within 200 pc of the SN position. The ages of local stars, some of which formed with the SN progenitor system, can constrain the time between star formation and SN, known as the delay time. We compare the local stellar properties to synthetic photometry of single-stellar populations, fitting to a range of possible delay times for each SN. With this sample, we uniquely constrain the delay-time distribution for SNe Iax, with a median and 1σ confidence interval delay time of $63_{- 15}^{+more »58} \times 10^{6}$ yr. The measured delay-time distribution provides an excellent constraint on the progenitor system for the class, indicating a preference for a WD progenitor system over a Wolf–Rayet progenitor star.« less
Circumstellar Medium Constraints on the Environment of Two Nearby Type Ia Supernovae: SN 2017cbv and SN 2020nlb
https://doi.org/10.3847/1538-4357/ac20da
Sand, D. J. ; Sarbadhicary, S. K. ; Pellegrino, C. ; Misra, K. ; Dastidar, R. ; Brown, P. J. ; Itagaki, K. ; Valenti, S. ; Swift, Jonathan J. ; Andrews, J. E. ; et al ( November 2021 , The Astrophysical Journal)
Abstract We present deep Chandra X-ray observations of two nearby Type Ia supernovae, SN 2017cbv and SN 2020nlb, which reveal no X-ray emission down to a luminosity L X ≲ 5.3 × 10 37 and ≲ 5.4 × 10 37 erg s −1 (0.3–10 keV), respectively, at ∼16–18 days after the explosion. With these limits, we constrain the pre-explosion mass-loss rate of the progenitor system to be M ̇ < 7.2 × 10 −9 and < 9.7 × 10 −9 M ⊙ yr −1 for each (at a wind velocity v w = 100 km s −1 and a radius of R ≈ 10 16 cm), assuming any X-ray emission would originate from inverse Compton emission from optical photons upscattered by the supernova shock. If the supernova environment was a constant-density medium, we would find a number density limit of n CSM < 36 and < 65 cm −3 , respectively. These X-ray limits rule out all plausible symbiotic progenitor systems, as well as large swathes of parameter space associated with the single degenerate scenario, such as mass loss at the outer Lagrange point and accretion winds. We also present late-time optical spectroscopy of SN 2020nlb, and set strong limitsmore »on any swept up hydrogen ( L H α < 2.7 × 10 37 erg s −1 ) and helium ( L He, λ 6678 < 2.7 × 10 37 erg s −1 ) from a nondegenerate companion, corresponding to M H ≲ 0.7–2 × 10 −3 M ⊙ and M He ≲ 4 × 10 −3 M ⊙ . Radio observations of SN 2020nlb at 14.6 days after explosion also yield a non-detection, ruling out most plausible symbiotic progenitor systems. While we have doubled the sample of normal Type Ia supernovae with deep X-ray limits, more observations are needed to sample the full range of luminosities and subtypes of these explosions, and set statistical constraints on their circumbinary environments.« less
https://doi.org/10.3847/2041-8213/ac7cef
Hosseinzadeh, Griffin, Sand, David J., Lundqvist, Peter, Andrews, Jennifer E., Bostroem, K. Azalee, Dong, Yize, Janzen, Daryl, Jencson, Jacob E., Lundquist, Michael, Meza Retamal, Nicolas E., Pearson, Jeniveve, Valenti, Stefano, Wyatt, Samuel, Burke, Jamison, Howell, D. Andrew, McCully, Curtis, Newsome, Megan, Gonzalez, Estefania Padilla, Pellegrino, Craig, Terreran, Giacomo, Kwok, Lindsey A., Jha, Saurabh W., Strader, Jay, Kundu, Esha, Ryder, Stuart D., Haislip, Joshua, Kouprianov, Vladimir, and Reichart, Daniel E.. Constraining the Progenitor System of the Type Ia Supernova 2021aefx. Retrieved from https://par.nsf.gov/biblio/10353858. The Astrophysical Journal Letters 933.2 Web. doi:10.3847/2041-8213/ac7cef.
Hosseinzadeh, Griffin, Sand, David J., Lundqvist, Peter, Andrews, Jennifer E., Bostroem, K. Azalee, Dong, Yize, Janzen, Daryl, Jencson, Jacob E., Lundquist, Michael, Meza Retamal, Nicolas E., Pearson, Jeniveve, Valenti, Stefano, Wyatt, Samuel, Burke, Jamison, Howell, D. Andrew, McCully, Curtis, Newsome, Megan, Gonzalez, Estefania Padilla, Pellegrino, Craig, Terreran, Giacomo, Kwok, Lindsey A., Jha, Saurabh W., Strader, Jay, Kundu, Esha, Ryder, Stuart D., Haislip, Joshua, Kouprianov, Vladimir, & Reichart, Daniel E.. Constraining the Progenitor System of the Type Ia Supernova 2021aefx. The Astrophysical Journal Letters, 933 (2). Retrieved from https://par.nsf.gov/biblio/10353858. https://doi.org/10.3847/2041-8213/ac7cef
Hosseinzadeh, Griffin, Sand, David J., Lundqvist, Peter, Andrews, Jennifer E., Bostroem, K. Azalee, Dong, Yize, Janzen, Daryl, Jencson, Jacob E., Lundquist, Michael, Meza Retamal, Nicolas E., Pearson, Jeniveve, Valenti, Stefano, Wyatt, Samuel, Burke, Jamison, Howell, D. Andrew, McCully, Curtis, Newsome, Megan, Gonzalez, Estefania Padilla, Pellegrino, Craig, Terreran, Giacomo, Kwok, Lindsey A., Jha, Saurabh W., Strader, Jay, Kundu, Esha, Ryder, Stuart D., Haislip, Joshua, Kouprianov, Vladimir, and Reichart, Daniel E.. "Constraining the Progenitor System of the Type Ia Supernova 2021aefx". The Astrophysical Journal Letters 933 (2). Country unknown/Code not available. https://doi.org/10.3847/2041-8213/ac7cef. https://par.nsf.gov/biblio/10353858.
place = {Country unknown/Code not available}, title = {Constraining the Progenitor System of the Type Ia Supernova 2021aefx}, url = {https://par.nsf.gov/biblio/10353858}, DOI = {10.3847/2041-8213/ac7cef}, abstractNote = {Abstract We present high-cadence optical and ultraviolet light curves of the normal Type Ia supernova (SN) 2021aefx, which shows an early bump during the first two days of observation. This bump may be a signature of interaction between the exploding white dwarf and a nondegenerate binary companion, or it may be intrinsic to the white dwarf explosion mechanism. In the case of the former, the short duration of the bump implies a relatively compact main-sequence companion star, although this conclusion is viewing-angle dependent. Our best-fit companion-shocking and double-detonation models both overpredict the UV luminosity during the bump, and existing nickel-shell models do not match the strength and timescale of the bump. We also present nebular spectra of SN 2021aefx, which do not show the hydrogen or helium emission expected from a nondegenerate companion, as well as a radio nondetection that rules out all symbiotic progenitor systems and most accretion disk winds. Our analysis places strong but conflicting constraints on the progenitor of SN 2021aefx; no current model can explain all of our observations.}, journal = {The Astrophysical Journal Letters}, volume = {933}, number = {2}, author = {Hosseinzadeh, Griffin and Sand, David J. and Lundqvist, Peter and Andrews, Jennifer E. and Bostroem, K. Azalee and Dong, Yize and Janzen, Daryl and Jencson, Jacob E. and Lundquist, Michael and Meza Retamal, Nicolas E. and Pearson, Jeniveve and Valenti, Stefano and Wyatt, Samuel and Burke, Jamison and Howell, D. Andrew and McCully, Curtis and Newsome, Megan and Gonzalez, Estefania Padilla and Pellegrino, Craig and Terreran, Giacomo and Kwok, Lindsey A. and Jha, Saurabh W. and Strader, Jay and Kundu, Esha and Ryder, Stuart D. and Haislip, Joshua and Kouprianov, Vladimir and Reichart, Daniel E.}, }