| Description: |
Among the supernovae (SNe) that show strong interaction with a circumstellar medium (CSM), there is a rare subclass of Type Ia supernovae, SNe Ia-CSM, which show strong narrow hydrogen emission lines much like SNe IIn but on top of a diluted Type Ia spectrum. The only previous systematic study of this class identified 16 SNe Ia-CSM, eight historic and eight from the Palomar Transient Factory (PTF). Now using the successor survey to PTF, the Zwicky Transient Facility (ZTF), we have classified 12 additional SNe Ia-CSM through the systematic Bright Transient Survey (BTS). Consistent with previous studies, we find these SNe to have slowly evolving optical light curves with peak absolute magnitudes between −19.1 and −21, spectra having weak Hβ and large Balmer decrements of ∼7. Out of the 10 SNe from our sample observed by NEOWISE, nine have 3σ detections, with some SNe showing a reduction in the red wing of Hα, indicative of newly formed dust. We do not find our SN Ia-CSM sample to have a significantly different distribution of equivalent widths of He i λ5876 than SNe IIn as observed in Silverman et al. The hosts tend to be late-type galaxies with recent star formation. We derive a rate estimate of 29 − 21 + 27 Gpc−3 yr−1 for SNe Ia-CSM, which is ∼0.02%-0.2% of the SN Ia rate. We also identify six ambiguous SNe IIn/Ia-CSM in the BTS sample and including them gives an upper limit rate of 0.07%-0.8%. This work nearly doubles the sample of well-studied Ia-CSM objects in Silverman et al., increasing the total number to 28. |
| Relation: |
https://researchonline.ljmu.ac.uk/id/eprint/19965/2/A%20Systematic%20Study%20of%20Ia-CSM%20Supernovae%20from%20the%20ZTF%20Bright%20Transient%20Survey.pdf; Sharma, Y, Sollerman, J, Fremling, C, Kulkarni, SR, De, K, Irani, I, Schulze, S, Strotjohann, NL, Gal-Yam, A, Maguire, K, Perley, DA ORCID logoorcid:0000-0001-8472-1996 , Bellm, EC, Kool, EC, Brink, TG, Bruch, R, Deckers, M, Dekany, R, Dugas, A, Filippenko, AV, Goldwasser, S, Graham, MJ, Graham, ML, Groom, SL, Hankins, M, Jencson, J, Johansson, JP, Karambelkar, V, Kasliwal, MM, Masci, FJ, Medford, MS, Neill, JD, Nir, G, Riddle, RL, Rigault, M, Schweyer, T, Terwel, JH, Yan, L, Yang, Y and Yao, Y (2023) A Systematic Study of Ia-CSM Supernovae from the ZTF Bright Transient Survey. Astrophysical Journal, 948 (1). ISSN 0004-637X |