SN 2018gj: A Short Plateau Type II Supernova with Persistent Blueshifted Ha Emission
We present an extensive, panchromatic photometric (UV, optical, and near-IR) and low-resolution optical spectroscopic coverage of a Type IIP supernova SN 2018gj that occurred on the outskirts of the host galaxy NGC 6217. From the V- band light curve, we estimate the plateau length to be ∼ 70 ± 2 day...
| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2023-01-01
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| Series: | The Astrophysical Journal |
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| Online Access: | https://doi.org/10.3847/1538-4357/acdf5e |
| _version_ | 1797728987764490240 |
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| author | Rishabh Singh Teja Avinash Singh D. K. Sahu G. C. Anupama Brajesh Kumar Tatsuya Nakaoka Koji S Kawabata Masayuki Yamanaka Ali Takey Miho Kawabata |
| author_facet | Rishabh Singh Teja Avinash Singh D. K. Sahu G. C. Anupama Brajesh Kumar Tatsuya Nakaoka Koji S Kawabata Masayuki Yamanaka Ali Takey Miho Kawabata |
| author_sort | Rishabh Singh Teja |
| collection | DOAJ |
| description | We present an extensive, panchromatic photometric (UV, optical, and near-IR) and low-resolution optical spectroscopic coverage of a Type IIP supernova SN 2018gj that occurred on the outskirts of the host galaxy NGC 6217. From the V- band light curve, we estimate the plateau length to be ∼ 70 ± 2 days, placing it among the very few well-sampled short plateau supernovae (SNe). With V -band peak absolute magnitude M _V ≤ −17.0 ± 0.1 mag, it falls in the middle of the luminosity distribution of the Type II SNe. The color evolution is typical to other Type II SNe except for an early elbow-like feature in the evolution of V − R color owing to its early transition from the plateau to the nebular phase. Using the expanding photospheric method, we present an independent estimate of the distance to SN 2018gj. We report the spectral evolution to be typical of a Type II SNe. However, we see a persistent blueshift in emission lines until the late nebular phase, not ordinarily observed in Type II SNe. The amount of radioactive nickel ( ^56 Ni) yield in the explosion was estimated to be 0.026 ± 0.007 M _⊙ . We infer from semianalytical modeling, nebular spectrum, and 1D hydrodynamical modeling that the probable progenitor was a red supergiant with a zero-age-main-sequence mass ≤13 M _⊙ . In the simulated hydrodynamical model light curves, reproducing the early optical bolometric light curve required an additional radiation source, which could be the interaction with the proximal circumstellar matter. |
| first_indexed | 2024-03-12T11:22:15Z |
| format | Article |
| id | doaj.art-c29bf8a08ec94ab388cfcc7fcdd743f6 |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-03-12T11:22:15Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj.art-c29bf8a08ec94ab388cfcc7fcdd743f62023-09-01T18:01:56ZengIOP PublishingThe Astrophysical Journal1538-43572023-01-01954215510.3847/1538-4357/acdf5eSN 2018gj: A Short Plateau Type II Supernova with Persistent Blueshifted Ha EmissionRishabh Singh Teja0https://orcid.org/0000-0002-0525-0872Avinash Singh1https://orcid.org/0000-0003-2091-622XD. K. Sahu2https://orcid.org/0000-0002-6688-0800G. C. Anupama3https://orcid.org/0000-0003-3533-7183Brajesh Kumar4https://orcid.org/0000-0001-7225-2475Tatsuya Nakaoka5Koji S Kawabata6https://orcid.org/0000-0001-6099-9539Masayuki Yamanaka7https://orcid.org/0000-0001-9456-3709Ali Takey8https://orcid.org/0000-0003-1423-5516Miho Kawabata9https://orcid.org/0000-0002-4540-4928Indian Institute of Astrophysics , II Block, Koramangala, Bengaluru-560034, Karnataka, India ; rishabh.teja@iiap.res.in, rsteja001@gmail.com; Pondicherry University , R.V. Nagar, Kalapet, Pondicherry-605014, UT of Puducherry, IndiaHiroshima Astrophysical Science Center, Hiroshima University , Higashi-Hiroshima, Hiroshima 739-8526, JapanIndian Institute of Astrophysics , II Block, Koramangala, Bengaluru-560034, Karnataka, India ; rishabh.teja@iiap.res.in, rsteja001@gmail.comIndian Institute of Astrophysics , II Block, Koramangala, Bengaluru-560034, Karnataka, India ; rishabh.teja@iiap.res.in, rsteja001@gmail.comAryabhatta Research Institute of Observational Sciences , Manora Peak, Nainital-263001, Uttarakhand, IndiaHiroshima Astrophysical Science Center, Hiroshima University , Higashi-Hiroshima, Hiroshima 739-8526, JapanHiroshima Astrophysical Science Center, Hiroshima University , Higashi-Hiroshima, Hiroshima 739-8526, JapanKagoshima University , Amanogawa Galaxy Astronomy Research Center, 1-21-35, Korimoto, Kagoshima 890-0065, Kyushu-Okinawa, JapanNational Research Institute of Astronomy and Geophysics (NRIAG) , Helwan 11421, Cairo, EgyptDepartment of Astronomy, Kyoto University , Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502, JapanWe present an extensive, panchromatic photometric (UV, optical, and near-IR) and low-resolution optical spectroscopic coverage of a Type IIP supernova SN 2018gj that occurred on the outskirts of the host galaxy NGC 6217. From the V- band light curve, we estimate the plateau length to be ∼ 70 ± 2 days, placing it among the very few well-sampled short plateau supernovae (SNe). With V -band peak absolute magnitude M _V ≤ −17.0 ± 0.1 mag, it falls in the middle of the luminosity distribution of the Type II SNe. The color evolution is typical to other Type II SNe except for an early elbow-like feature in the evolution of V − R color owing to its early transition from the plateau to the nebular phase. Using the expanding photospheric method, we present an independent estimate of the distance to SN 2018gj. We report the spectral evolution to be typical of a Type II SNe. However, we see a persistent blueshift in emission lines until the late nebular phase, not ordinarily observed in Type II SNe. The amount of radioactive nickel ( ^56 Ni) yield in the explosion was estimated to be 0.026 ± 0.007 M _⊙ . We infer from semianalytical modeling, nebular spectrum, and 1D hydrodynamical modeling that the probable progenitor was a red supergiant with a zero-age-main-sequence mass ≤13 M _⊙ . In the simulated hydrodynamical model light curves, reproducing the early optical bolometric light curve required an additional radiation source, which could be the interaction with the proximal circumstellar matter.https://doi.org/10.3847/1538-4357/acdf5eObservational astronomyType II supernovaeHydrodynamical simulationsRed supergiant stars |
| spellingShingle | Rishabh Singh Teja Avinash Singh D. K. Sahu G. C. Anupama Brajesh Kumar Tatsuya Nakaoka Koji S Kawabata Masayuki Yamanaka Ali Takey Miho Kawabata SN 2018gj: A Short Plateau Type II Supernova with Persistent Blueshifted Ha Emission The Astrophysical Journal Observational astronomy Type II supernovae Hydrodynamical simulations Red supergiant stars |
| title | SN 2018gj: A Short Plateau Type II Supernova with Persistent Blueshifted Ha Emission |
| title_full | SN 2018gj: A Short Plateau Type II Supernova with Persistent Blueshifted Ha Emission |
| title_fullStr | SN 2018gj: A Short Plateau Type II Supernova with Persistent Blueshifted Ha Emission |
| title_full_unstemmed | SN 2018gj: A Short Plateau Type II Supernova with Persistent Blueshifted Ha Emission |
| title_short | SN 2018gj: A Short Plateau Type II Supernova with Persistent Blueshifted Ha Emission |
| title_sort | sn 2018gj a short plateau type ii supernova with persistent blueshifted ha emission |
| topic | Observational astronomy Type II supernovae Hydrodynamical simulations Red supergiant stars |
| url | https://doi.org/10.3847/1538-4357/acdf5e |
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