Characterizing the Ordinary Broad-line Type Ic SN 2023pel from the Energetic GRB 230812B
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Published:2024-01-01
Issue:2
Volume:960
Page:L18
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ISSN:2041-8205
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Container-title:The Astrophysical Journal Letters
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language:
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Short-container-title:ApJL
Author:
Srinivasaragavan Gokul P.ORCID, Swain VishwajeetORCID, O’Connor BrendanORCID, Anand ShreyaORCID, Ahumada TomásORCID, Perley DanielORCID, Stein RobertORCID, Sollerman JesperORCID, Fremling ChristofferORCID, Cenko S. BradleyORCID, Antier S.ORCID, Guessoum NidhalORCID, Hussenot-Desenonges ThomasORCID, Hello Patrice, Lesage StephenORCID, Hammerstein EricaORCID, Miller M. ColemanORCID, Andreoni IgorORCID, Bhalerao VarunORCID, Bloom Joshua S.ORCID, Dutta AnirbanORCID, Gal-Yam AvishayORCID, Hinds K-RyanORCID, Jaodand AmrutaORCID, Kasliwal MansiORCID, Kumar HarshORCID, Kutyrev Alexander S.ORCID, Ragosta FabioORCID, Ravi VikramORCID, Sharma KrittiORCID, Singh Teja RishabhORCID, Yang ShengORCID, Anupama G. C.ORCID, Bellm Eric C.ORCID, Coughlin Michael W.ORCID, Mahabal Ashish A., Masci Frank J.ORCID, Pathak UtkarshORCID, Purdum JosiahORCID, Roberts Oliver J.ORCID, Smith RogerORCID, Wold AveryORCID
Abstract
Abstract
We report observations of the optical counterpart of the long gamma-ray burst (GRB) GRB 230812B and its associated supernova (SN) SN 2023pel. The proximity (z = 0.36) and high energy (E
γ,iso ∼ 1053 erg) make it an important event to study as a probe of the connection between massive star core collapse and relativistic jet formation. With a phenomenological power-law model for the optical afterglow, we find a late-time flattening consistent with the presence of an associated SN. SN 2023pel has an absolute peak r-band magnitude of M
r
= −19.46 ± 0.18 mag (about as bright as SN 1998bw) and evolves on quicker timescales. Using a radioactive heating model, we derive a nickel mass powering the SN of M
Ni = 0.38 ± 0.01 M
⊙ and a peak bolometric luminosity of L
bol ∼ 1.3 × 1043 erg s−1. We confirm SN 2023pel’s classification as a broad-line Type Ic SN with a spectrum taken 15.5 days after its peak in the r band and derive a photospheric expansion velocity of v
ph = 11,300 ± 1600 km s−1 at that phase. Extrapolating this velocity to the time of maximum light, we derive the ejecta mass M
ej = 1.0 ± 0.6 M
⊙ and kinetic energy
E
KE
=
1.3
−
1.2
+
3.3
×
10
51
erg
. We find that GRB 230812B/SN 2023pel has SN properties that are mostly consistent with the overall GRB-SN population. The lack of correlations found in the GRB-SN population between SN brightness and E
γ,iso for their associated GRBs across a broad range of 7 orders of magnitude provides further evidence that the central engine powering the relativistic ejecta is not coupled to the SN powering mechanism in GRB-SN systems.
Funder
NASA ∣ Goddard Space Flight Center NASA ∣ SMD ∣ Astrophysics Division National Science Foundation MOST ∣ National Natural Science Foundation of China Heising-Simons Foundation
Publisher
American Astronomical Society
Subject
Space and Planetary Science,Astronomy and Astrophysics
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