SN 2022ann: a Type Icn supernova from a dwarf galaxy that reveals helium in its circumstellar environment

Journal Article · Mon May 15 00:00:00 EDT 2023 · Monthly Notices of the Royal Astronomical Society

DOI:https://doi.org/10.1093/mnras/stad1433· OSTI ID:2424733

Davis, K W ^[1]; Taggart, K ^[1]; Tinyanont, S ^[2]; Foley, R J ^[1]; Villar, V A ^[3]; Izzo, L ^[4]; Angus, C R ^[4]; Bustamante-Rosell, M J ^[1]; Coulter, D A ^[1]; Earl, N ^[5]; Farias, D ^[4]; Hjorth, J ^[4]; Huber, M E ^[6]; Jones, D O ^[7]; Kelly, P L ^[8]; Kilpatrick, C D ^[9]; Langeroodi, D ^[4]; Miao, H-Y ^[10]; Pellegrino, C M ^[11]; Ramirez-Ruiz, E ^[1] ; Ransome, C L ^[3]; Rest, S ^[12]; Siebert, M R ^[13]; Terreran, G ^[14]; Thornton, I M ^[3]; Yadavalli, S K ^[3]; Zeimann, G R ^[15]; Auchettl, K ^[16]; Bom, C R ^[17]; Brink, T G ^[18]; Burke, J ^[11]; Camacho-Neves, Y ^[19]; Chambers, K C ^[6]; de Boer, T J L ^[6]; DeMarchi, L ^[9]; Filippenko, A V ^[18]; Galbany, L ^[20]; Gall, C ^[4]; Gao, H ^[6]; Herpich, F R ^[21]; Howell, D A ^[11]; Jacobson-Galan, W V ^[18]; Jha, S W ^[19]; Kanaan, A ^[10]; Khetan, N ^[4]; Kwok, L A ^[19]; Lai, Z ^[1]; Larison, C ^[19]; Lin, C-C ^[6]; Loertscher, K C ^[1]; Magnier, E A ^[6]; McCully, C ^[14]; McGill, P ^[1]; Newsome, M ^[11]; Padilla Gonzalez, E ^[11]; Pan, Y-C ^[10]; Rest, A ^[22]; Rho, J ^[23]; Ribeiro, T ^[24]; Santos, A ^[17]; Schoenell, W ^[25]; Sharief, S N ^[5]; Smith, K W ^[26]; Wainscoat, R J ^[6]; Wang, Q ^[12]; Zenati, Y ^[12]; Zheng, W ^[18]

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1. Department of Astronomy and Astrophysics, University of California , Santa Cruz, CA 95064, USA
2. Department of Astronomy and Astrophysics, University of California , Santa Cruz, CA 95064, USA; National Astronomical Research Institute of Thailand , 260 Moo 4, Donkaew, Maerim, Chiang Mai 50180, Thailand
3. Department of Astronomy and Astrophysics, The Pennsylvania State University , University Park, PA 16802, USA
4. DARK, Niels Bohr Institute, University of Copenhagen , Jagtvej 128, 2200 Copenhagen, Denmark
5. Department of Astronomy, University of Illinois at Urbana-Champaign , 1002 W. Green St, IL 61801 , USA
6. Institute for Astronomy, University of Hawaii , 2680 Woodlawn Drive , Honolulu, HI 96822, USA
7. Department of Astronomy and Astrophysics, University of California , Santa Cruz, CA 95064, USA; Gemini Observatory/NSF’s NOIRLab , 670 N. A’ohoku Place , Hilo, HI 96720, USA
8. Minnesota Institute for Astrophysics, University of Minnesota , 116 Church Street SE , Minneapolis, MN 55455, USA
9. Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) and Department of Physics and Astronomy, Northwestern University , Evanston, IL 60208, USA
10. Graduate Institute of Astronomy, National Central University , 300 Zhongda Road , Zhongli, Taoyuan 32001, Taiwan
11. Las Cumbres Observatory , 6740 Cortona Drive , Suite 102, Goleta, CA 93117-5575, USA; Department of Physics, University of California , Santa Barbara, CA 93106-9530, USA
12. Department of Physics and Astronomy, The Johns Hopkins University , Baltimore, MD 21218, USA
13. Space Telescope Science Institute , Baltimore, MD 21218, USA
14. Las Cumbres Observatory , 6740 Cortona Drive , Suite 102, Goleta, CA 93117-5575, USA
15. Hobby Eberly Telescope, University of Texas , Austin, TX 78712, USA
16. Department of Astronomy and Astrophysics, University of California , Santa Cruz, CA 95064, USA; School of Physics, The University of Melbourne , VIC 3010, Australia; ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D) , Australia
17. Centro Brasileiro de Pesquisas Físicas , Rua Dr Xavier Sigaud 150, CEP 22290-180 , Rio de Janeiro, RJ, Brazil
18. Department of Astronomy, University of California , Berkeley, CA 94720-3411, USA
19. Department of Physics and Astronomy, Rutgers, the State University of New Jersey , 136 Frelinghuysen Road , Piscataway, NJ 08854-8019, USA
20. Institute of Space Sciences (ICE, CSIC) , Campus UAB, Carrer de Can Magrans, s/n, E-08193 Barcelona, Spain; Institut d’Estudis Espacials de Catalunya (IEEC) , E-08034 Barcelona, Spain
21. Department of Astronomy, University of Sao Paulo , Rua do Matao, 1226, 05509-900 Sao Paulo, Brazil
22. Space Telescope Science Institute , Baltimore, MD 21218, USA; Department of Physics and Astronomy, The Johns Hopkins University , Baltimore, MD 21218, USA
23. SETI Institute , 339 N. Bernardo Ave., Ste. 200 , Mountain View, CA 94043, USA
24. Departamento de Astronomia, Instituto de Física, Universidade Federal do Rio Grande do Sul (UFRGS) , Av. Bento Goncalves 9500
25. NOAO , PO Box 26732, Tucson, AZ 85726, USA
26. Astrophysics Research Centre, School of Mathematics and Physics, Queen’s University Belfast , Belfast BT7 1NN, UK

Here, we present optical and near-infrared (NIR) observations of the Type Icn supernova (SN Icn) 2022ann, the fifth member of its newly identified class of SNe. Its early optical spectra are dominated by narrow carbon and oxygen P-Cygni features with absorption velocities of ∼800 km s⁻¹; slower than other SNe Icn and indicative of interaction with a dense, H/He-poor circumstellar medium (CSM) that is outflowing slower than typical Wolf–Rayet wind velocities of >1000 km s⁻¹. We identify helium in NIR spectra 2 weeks after maximum and in optical spectra at 3 weeks, demonstrating that the CSM is not fully devoid of helium. Unlike other SNe Icn, the spectra of SN 2022ann never develop broad features from SN ejecta, including in the nebular phase. Compared to other SNe Icn, SN 2022ann has a low luminosity (o-band absolute magnitude of ∼−17.7), and evolves slowly. The bolometric light curve is well-modelled by 4.8 M_⊙ of SN ejecta interacting with 1.3 M_⊙ of CSM. We place an upper limit of 0.04 M_⊙ of ⁵⁶Ni synthesized in the explosion. The host galaxy is a dwarf galaxy with a stellar mass of 10^7.34 M_⊙ (implied metallicity of log(Z/Z_⊙) ≈ 0.10) and integrated star-formation rate of log (SFR) = −2.20 M_⊙ yr⁻¹; both lower than 97 per cent of galaxies observed to produce core-collapse supernovae, although consistent with star-forming galaxies on the galaxy Main Sequence. The low CSM velocity, nickel and ejecta masses, and likely low-metallicity environment disfavour a single Wolf–Rayet progenitor star. Instead, a binary companion is likely required to adequately strip the progenitor and produce a low-velocity outflow.

• Research Organization: US Department of Energy (USDOE), Washington, DC (United States). Dark Energy Survey (DES) Collaboration
• Sponsoring Organization: National Aeronautics and Space Administration (NASA); National Council for Scientific and Technological Development (CNPq); National Science Foundation (NSF); São Paulo Research Foundation (FAPESP); USDOE
• OSTI ID: 2424733
• Journal Information: Monthly Notices of the Royal Astronomical Society, Journal Name: Monthly Notices of the Royal Astronomical Society Journal Issue: 2 Vol. 523; ISSN 0035-8711; ISSN 1365-2966
• Publisher: Oxford University Press
• Country of Publication: United States
• Language: English

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binaries
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