Abstract Details

Name: Anjasha Gangopadhyay
Affiliation: Aryabhatta Research Institute of observational sciencES (ARIES), Manora Peak, Nainital, India
Conference ID: ASI2020_148
Title : Flash ionization signatures in the Type Ibn supernova SN~2019uo
Authors and Co-Authors : Anjasha Gangopadhyay, Kuntal Misra, Diachi Hiramatsu, Shan-Qin Wang, Griffin Hosseinzadeh, Xiaofeng Wang, Stefano Valenti, D. Andrew Howell, Iair Arcavi, G.C. Anupama, D.K. Sahu, Raya Dastidar, Brajesh Kumar, Mridweeka Singh, Avinash Singh, Brijesh Kumar, S.B. Pandey
Abstract Type : Poster
Abstract Category : Extragalactic Astronomy
Abstract : Supernovae (SNe) that are embedded in dense circumstellar medium (CSM) show early spectral signatures (< 10 days) owing to recombination of CSM ionised by shock breakout flash. ``Flash spectroscopy”, is thus, a rare and unique tool to probe the CSM for the case of interacting SNe (Type IIn and Ibn) which show narrow emission lines of Hydrogen and Helium due to interaction with dense CSM. We present photometric and spectroscopic observations of the Type Ibn supernova (SN) 2019uo, the second ever SN~Ibn with flash ionization (\ion{He}{2}, \ion{C}{3}, \ion{N}{3}) features in its early spectra. SN~2019uo displays a rapid post-peak luminosity decline of 0.1 mag d$^{-1}$ similar to most of the SNe~Ibn, but is fainter ($M_V = -18.30 \pm 0.24$\ mag at peak) than a typical SN~Ibn and shows peculiar color evolution that places it between SNe~Ib and the most extreme SNe~Ibn. The bolometric light curve is best described by a $^{56}$Ni + circumstellar interaction model. SN~2019uo belongs to the ``P~Cygni" sub-class of SNe~Ibn and shows faster evolution in velocities compared to the ``emission" sub-class.