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| Main Authors: | , , , , , , |
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| Format: | Preprint |
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2026
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| Online Access: | https://arxiv.org/abs/2605.16916 |
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| _version_ | 1866916018491752448 |
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| author | Yamanaka, Masayuki Nagayama, Takahiro Kumano, Akari Sahu, Devendra Kumar Singh, Avinash Das, Hrishav Anupama, G. C. |
| author_facet | Yamanaka, Masayuki Nagayama, Takahiro Kumano, Akari Sahu, Devendra Kumar Singh, Avinash Das, Hrishav Anupama, G. C. |
| contents | We present near-infrared (NIR) and optical observations of the highly reddened and moderately energetic Type Ib supernova (SN) 2023dbc, {\bf covering a period from} 2 to 136 days after the explosion. By comparing its color {\bf evolution}, specifically in $r-JHK_{\mathrm{s}}$ and $i-JHK_{\mathrm{s}}$, with those of broad-lined Type Ic (Ic-BL) and Type IIb SNe, we estimate a significant extinction of $A_{V}=4.1\pm0.1$\,mag toward the SN. The extinction-corrected peak absolute magnitudes are $M_{J} = -16.8\pm0.2$\,mag, $M_{H} = -16.8\pm0.2$\,mag, and $M_{K_{\mathrm{s}}} = -17.0\pm0.2$\,mag. The SN {\bf exhibited} an $r$-band rise time of 14.9 days. The spectra {\bf display} broad features {\bf indicative of} high expansion velocities; the He~{\sc i} line velocity was measured at $16,000\,\mathrm{km\,s^{-1}}$ at $t=-4$\,d. Its spectral profile is broader than {\bf those} of typical moderately energetic Type Ib SNe, {\bf yet narrower than those of Type Ic-BL SNe, placing it in an intermediate category}. Based on the light-curve timescale and velocity, we estimate {\bf a} kinetic energy of $E_k = (4.1\pm0.7) \times 10^{51}$\,erg, {\bf an} ejecta mass of $M_{\mathrm{ej}} = 2.3\pm0.7\,M_{\odot}$, and a radioactive $^{56}\mathrm{Ni}$ mass of $(3.8\pm0.1) \times 10^{-2}\,M_{\odot}$. {\bf An} analysis using a two-component model suggests a steep density profile in the outer layer {\bf contrasted with} a dense inner core, {\bf which implies} ejecta asphericity. The low $^{56}\mathrm{Ni}$ mass is consistent with a partial fallback scenario. We conclude that SN 2023dbc originated from an aspherical explosion with partial core fallback, {\bf arising} from a progenitor ($M_{\mathrm{ini}} \simeq 15\,M_{\odot}$) that had retained {\bf its} helium envelope {\bf within} a binary system. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2605_16916 |
| institution | arXiv |
| publishDate | 2026 |
| record_format | arxiv |
| spellingShingle | SN 2023dbc in M108: Optical and Near-Infrared Observations of a Highly-Obscured, Moderately Energetic Stripped-Envelope Supernova Yamanaka, Masayuki Nagayama, Takahiro Kumano, Akari Sahu, Devendra Kumar Singh, Avinash Das, Hrishav Anupama, G. C. High Energy Astrophysical Phenomena We present near-infrared (NIR) and optical observations of the highly reddened and moderately energetic Type Ib supernova (SN) 2023dbc, {\bf covering a period from} 2 to 136 days after the explosion. By comparing its color {\bf evolution}, specifically in $r-JHK_{\mathrm{s}}$ and $i-JHK_{\mathrm{s}}$, with those of broad-lined Type Ic (Ic-BL) and Type IIb SNe, we estimate a significant extinction of $A_{V}=4.1\pm0.1$\,mag toward the SN. The extinction-corrected peak absolute magnitudes are $M_{J} = -16.8\pm0.2$\,mag, $M_{H} = -16.8\pm0.2$\,mag, and $M_{K_{\mathrm{s}}} = -17.0\pm0.2$\,mag. The SN {\bf exhibited} an $r$-band rise time of 14.9 days. The spectra {\bf display} broad features {\bf indicative of} high expansion velocities; the He~{\sc i} line velocity was measured at $16,000\,\mathrm{km\,s^{-1}}$ at $t=-4$\,d. Its spectral profile is broader than {\bf those} of typical moderately energetic Type Ib SNe, {\bf yet narrower than those of Type Ic-BL SNe, placing it in an intermediate category}. Based on the light-curve timescale and velocity, we estimate {\bf a} kinetic energy of $E_k = (4.1\pm0.7) \times 10^{51}$\,erg, {\bf an} ejecta mass of $M_{\mathrm{ej}} = 2.3\pm0.7\,M_{\odot}$, and a radioactive $^{56}\mathrm{Ni}$ mass of $(3.8\pm0.1) \times 10^{-2}\,M_{\odot}$. {\bf An} analysis using a two-component model suggests a steep density profile in the outer layer {\bf contrasted with} a dense inner core, {\bf which implies} ejecta asphericity. The low $^{56}\mathrm{Ni}$ mass is consistent with a partial fallback scenario. We conclude that SN 2023dbc originated from an aspherical explosion with partial core fallback, {\bf arising} from a progenitor ($M_{\mathrm{ini}} \simeq 15\,M_{\odot}$) that had retained {\bf its} helium envelope {\bf within} a binary system. |
| title | SN 2023dbc in M108: Optical and Near-Infrared Observations of a Highly-Obscured, Moderately Energetic Stripped-Envelope Supernova |
| topic | High Energy Astrophysical Phenomena |
| url | https://arxiv.org/abs/2605.16916 |