Abstract
We present UV-optical-near-infrared observations and modeling of supernova (SN) 2024ggi, a type II supernova (SN II) located in NGC 3621 at 7.2 Mpc. Early-time (“flash”) spectroscopy of SN 2024ggi within +0.8 days of discovery shows emission lines of H i, He i, C iii, and N iii with a narrow core and broad, symmetric wings (i.e., “IIn-like”) arising from the photoionized, optically thick, unshocked circumstellar material (CSM) that surrounded the progenitor star at shock breakout (SBO). By the next spectral epoch at +1.5 days, SN 2024ggi showed a rise in ionization as emission lines of He ii, C iv, N iv/v, and O v became visible. This phenomenon is temporally consistent with a blueward shift in the UV-optical colors, both likely the result of SBO in an extended, dense CSM. The IIn-like features in SN 2024ggi persist on a timescale of t IIn = 3.8 ± 1.6 days, at which time a reduction in CSM density allows the detection of Doppler-broadened features from the fastest SN material. SN 2024ggi has peak UV-optical absolute magnitudes of M w2 = −18.7 mag and M g = −18.1 mag, respectively, that are consistent with the known population of CSM-interacting SNe II. Comparison of SN 2024ggi with a grid of radiation hydrodynamics and non-local thermodynamic equilibrium radiative-transfer simulations suggests a progenitor mass-loss rate of M ̇ = 10 − 2 M ⊙ yr−1 (v w = 50 km s−1), confined to a distance of r < 5 × 1014 cm. Assuming a wind velocity of v w = 50 km s−1, the progenitor star underwent an enhanced mass-loss episode in the last ∼3 yr before explosion.
| Original language | English (US) |
|---|---|
| Article number | 177 |
| Journal | Astrophysical Journal |
| Volume | 972 |
| Issue number | 2 |
| DOIs | |
| State | Published - Sep 1 2024 |
Funding
M.R.D. acknowledges support from the NSERC through grant RGPIN-2019-06186, the Canada Research Chairs Program, and the Dunlap Institute at the University of Toronto. Parts of this research were supported by the Australian Research Council Discovery Early Career Researcher Award (DECRA) through project number DE230101069. Y.-C.P. is supported by the National Science and Technology Council (NSTC grant 109-2112-M-008-031-MY3). C.G. is supported by a VILLUM FONDEN Young Investigator Grant (project number 25501). D.M. acknowledges NSF support from grants PHY-2209451 and AST-2206532. A.S. acknowledges the financial support from CNPq (402577/2022-1). G.D. is supported by the H2020 European Research Council grant No. 758638. C.R.B. acknowledges the financial support from CNPq (316072/2021-4), from FAPERJ (grants 201.456/2022 and 210.330/2022), and the FINEP contract 01.22.0505.00 (ref. 1891/22). This research is based on observations made with the Thai Robotic Telescope under program ID TRTC11B006, which is operated by the National Astronomical Research Institute of Thailand (Public Organization). Part of the data were obtained with the REM telescope, located in Chile and operated by the d\u2019REM team for INAF. This work is supported by the National Science Foundation under Cooperative Agreement PHY-2019786 (The NSF AI Institute for Artificial Intelligence and Fundamental Interactions; http://iaifi.org/ ). IRAF is distributed by NOAO, which is operated by AURA, Inc., under cooperative agreement with the National Science Foundation (NSF). The UCSC team is supported in part by NASA grants NNG17PX03C and 80NSSC22K1518, NSF grant AST-1815935, and by a fellowship from the David and Lucile Packard Foundation to R.J.F. This research was supported by the Munich Institute for Astro-, Particle and BioPhysics (MIAPbP), which is funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany\u2019s Excellence Strategy\u2014EXC-2094\u2014390783311. YSE-PZ (Coulter et al. ) was developed by the UC Santa Cruz Transients Team with support from NASA grants NNG17PX03C, 80NSSC19K1386, and 80NSSC20K0953; NSF grants AST-1518052, AST-1815935, and AST-1911206; the Gordon & Betty Moore Foundation; the Heising-Simons Foundation; a fellowship from the David and Lucile Packard Foundation to R.J.F.; Gordon and Betty Moore Foundation postdoctoral fellowships and a NASA Einstein fellowship, as administered through the NASA Hubble Fellowship program and grant HST-HF2-51462.001 to D.O.J.; and a National Science Foundation Graduate Research Fellowship, administered through grant No. DGE-1339067 to D.A.C. W.J.-G. is supported by the National Science Foundation Graduate Research Fellowship Program under grant No. DGE-1842165. W.J.-G. acknowledges support through NASA grants in support of Hubble Space Telescope programs GO-16075 and 16500. This research was supported in part by the National Science Foundation under grant No. NSF PHY-1748958. R.M. acknowledges support from the National Science Foundation under Award Nos. AST-2221789 and AST-2224255. The Margutti team at UC Berkeley is partially funded by the Heising-Simons Foundation under grants #2018-0911 and #2021-3248 (PI: Margutti). This work has made use of data from the Asteroid Terrestrial-impact Last Alert System (ATLAS) project. The Asteroid Terrestrial-impact Last Alert System (ATLAS) project is primarily funded to search for near-Earth asteroids through NASA grants NN12AR55G, 80NSSC18K0284, and 80NSSC18K1575; by-products of the NEO search include images and catalogs from the survey area. This work was partially funded by Kepler/K2 grant J1944/80NSSC19K0112 and HST GO-15889, and STFC grants ST/T000198/1 and ST/S006109/1. The ATLAS science products have been made possible through the contributions of the University of Hawaii Institute for Astronomy, the Queen's University Belfast, the Space Telescope Science Institute, the South African Astronomical Observatory, and The Millennium Institute of Astrophysics (MAS), Chile.
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science