The SN 2023ixf Progenitor in M101. II. Properties

Abstract

We follow our first paper with an analysis of the ensemble of the extensive preexplosion ground- and space-based infrared observations of the red supergiant (RSG) progenitor candidate for the nearby core-collapse supernova SN 2023ixf in Messier 101, together with optical data prior to the explosion obtained with the Hubble Space Telescope (HST). We have confirmed the association of the progenitor candidate with the supernova (SN), as well as constrained the metallicity at the SN site, based on SN observations with instruments at Gemini-North. The internal host extinction to the SN has also been confirmed from a high-resolution Keck spectrum. We fit the observed spectral energy distribution (SED) for the star, accounting for its intrinsic variability, with dust radiative-transfer modeling, which assumes a silicate-rich dust shell ahead of the underlying stellar photosphere. The star is heavily dust obscured, likely the dustiest progenitor candidate yet encountered. We found median estimates of the star’s effective temperature and luminosity of 2770 K and 9.0 × 104 L ⊙, with 68% credible intervals of 2340–3150 K and (7.5–10.9) × 104 L ⊙, respectively. The candidate may have a Galactic RSG analog, IRC −10414, with a strikingly similar SED and luminosity. Via comparison with single-star evolutionary models we have constrained the initial mass of the progenitor candidate from 12 M ⊙ to as high as 14 M ⊙. We have had available to us an extraordinary view of the SN 2023ixf progenitor candidate, which should be further followed up in future years with HST and the James Webb Space Telescope.

Early-phase Simultaneous Multiband Observations of the Type II Supernova SN 2024ggi with Mephisto

“…The RSG progenitors may be enshrouded in a dusty shell of CSM as revealed in SN 2012aw (Fraser et al 2012;Van Dyk et al 2012), SN 2017eaw (Kilpatrick & Foley 2018Rui et al 2019;Van Dyk et al 2019), and SN 2023ixf (Kilpatrick et al 2023Pledger & Shara 2023;Soraisam et al 2023;Neustadt et al 2024;Van Dyk et al 2024). However, in our investigation of the SN 2024ggi progenitor, the dust mass contribution has not been accounted for, and hence, some enhancement in the estimated mass limit is possible.…”

“…In recent years, the direct detection of SNe II-P progenitors has been possible in a few dozen cases thanks to highresolution images from space-and ground-based facilities (see, e.g., Smartt 2009Smartt , 2015Tartaglia et al 2017;Van Dyk 2017). Several studies of the SN 2023ixf progenitor were made due to its proximity to the Earth (Dong et al 2023;Jencson et al 2023;Kilpatrick et al 2023;Liu et al 2023;Niu et al 2023;Panjkov et al 2023;Pledger & Shara 2023;Soraisam et al 2023;Bersten et al 2024;Neustadt et al 2024;Ransome et al 2024;Van Dyk et al 2024). As the RSG progenitors have a large mass range (Eldridge et al 2017;Davies & Beasor 2020), any new possible identification is important to better constrain the mass limit.…”

“…The isochrones that match the measurement best have an age of ∼10 (red) or 15 (green) Myr, with an initial mass of 17 or 14 M e and a metallicity of Z = 0.025 or Z = 0.01. In different studies, the progenitor of SN 2023ixf has been identified as an RSG with an estimated mass range between ∼9 and 22, e.g., 17 ± 4 M e (Jencson et al 2023), 11 ± 2 M e (Kilpatrick et al 2023), 20-22 M e (Liu et al 2023), 8-10 M e (Pledger & Shara 2023), 20 ± 4 M e (Soraisam et al 2023), 9-14 M e (Neustadt et al 2024), 14-20 M e , (Ransome et al 2024), and 12-14 M e (Van Dyk et al 2024). This indicates that the progenitor of SN 2024ggi was a moderately massive star.…”

“…However, in our investigation of the SN 2024ggi progenitor, the dust mass contribution has not been accounted for, and hence, some enhancement in the estimated mass limit is possible. Xiang et al (2024) found that the dust shell surrounding the SN 2024ggi progenitor is significantly optically thin (optical depth τ V = ∼0.3) than SN 2023ixf (τ V = ∼10-13; Neustadt et al 2024;Van Dyk et al 2024). This indicates very limited influence of dust on the SN 2024ggi progenitor's spectral energy distribution.…”

The Red Supergiant Progenitor of Type II Supernova 2024ggi

“…These stars retain most of their hydrogen envelopes before core collapse, producing supernovae with persistent and prominent hydrogen lines in their spectra. With prediscovery images, mainly thanks to space-based telescopes such as the Hubble Space Telescope (HST), progenitors have been identified for dozens of SNe II (Smartt 2015) and more recently for SN 2017eaw (Kilpatrick & Foley 2018;Van Dyk et al 2019;Rui et al 2019), SN 2022acko (Van Dyk et al 2023, and SN 2023ixf (Kilpatrick et al 2023;Jencson et al 2023;Soraisam et al 2023;Niu et al 2023;Xiang et al 2024;Ransome et al 2024;Dong et al 2023;Qin et al 2023;Van Dyk et al 2024). These observations and analysis have confirmed the connections between RSGs and SNe IIP/IIL.…”