학술논문
SN 2023zaw: an ultra-stripped, nickel-poor supernova from a low-mass progenitor
Document Type
Working Paper
Author
Das, Kaustav K.; Fremling, Christoffer; Kasliwal, Mansi M.; Schulze, Steve; Sollerman, Jesper; Karambelkar, Viraj; Rose, Sam; Anand, Shreya; Andreoni, Igor; Aubert, Marie; Brennan, Sean J.; Cenko, S. Bradley; Coughlin, Michael W.; O'Connor, B.; De, Kishalay; Fuller, Jim; Graham, Matthew; Hammerstein, Erica; Haynie, Annastasia; Hinds, K-Ryan; Kleiser, Io; Kulkarni, S. R.; Lin, Zeren; Liu, Chang; Mahabal, Ashish A.; Martin, Christopher; Miller, Adam A.; Neill, James D.; Perley, Daniel A.; Pessi, Priscila J.; Prusinski, Nikolaus Z.; Purdum, Josiah; Ravi, Vikram; Rusholme, Ben; Wu, Samantha; Wold, Avery; Yan, Lin
Source
The Astrophysical Journal Letters, July 2024, Volume 969, Issue 1, id.L11, 18 pp
Subject
Language
Abstract
We present SN 2023zaw $-$ a sub-luminous ($\mathrm{M_r} = -16.7$ mag) and rapidly-evolving supernova ($\mathrm{t_{1/2,r}} = 4.9$ days), with the lowest nickel mass ($\approx0.002$ $\mathrm{M_\odot}$) measured among all stripped-envelope supernovae discovered to date. The photospheric spectra are dominated by broad He I and Ca NIR emission lines with velocities of $\sim10\ 000 - 12\ 000$ $\mathrm{km\ s^{-1}}$. The late-time spectra show prominent narrow He I emission lines at $\sim$1000$\ \mathrm{km\ s^{-1}}$, indicative of interaction with He-rich circumstellar material. SN 2023zaw is located in the spiral arm of a star-forming galaxy. We perform radiation-hydrodynamical and analytical modeling of the lightcurve by fitting with a combination of shock-cooling emission and nickel decay. The progenitor has a best-fit envelope mass of $\approx0.2$ $\mathrm{M_\odot}$ and an envelope radius of $\approx50$ $\mathrm{R_\odot}$. The extremely low nickel mass and low ejecta mass ($\approx0.5$ $\mathrm{M_\odot}$) suggest an ultra-stripped SN, which originates from a mass-losing low mass He-star (ZAMS mass $<$ 10 $\mathrm{M_\odot}$) in a close binary system. This is a channel to form double neutron star systems, whose merger is detectable with LIGO. SN 2023zaw underscores the existence of a previously undiscovered population of extremely low nickel mass ($< 0.005$ $\mathrm{M_\odot}$) stripped-envelope supernovae, which can be explored with deep and high-cadence transient surveys.
Comment: Accepted for publication in ApJL
Comment: Accepted for publication in ApJL