Year: 2020
Type: article
Abstract: We present observations of ZTF18abfcmjw (SN2019dge), a helium-rich supernova with a fast-evolving light curve indicating an extremely low ejecta mass (≈0.33 M ⊙) and low kinetic energy (≈1.3 × 1050 erg). Early-time (<4 days after explosion) photometry reveals evidence of shock cooling from an extended helium-rich envelope of ∼0.1 M ⊙ located ∼1.2 × 1013 cm from the progenitor. Early-time He II line emission and subsequent spectra show signatures of interaction with helium-rich circumstellar material, which extends from ≳5 × 1013 cm to ≳2 × 1016 cm. We interpret SN2019dge as a helium-rich supernova from an ultra-stripped progenitor, which originates from a close binary system consisting of a mass-losing helium star and a low-mass main-sequence star or a compact object (i.e., a white dwarf, a neutron star, or a black hole). We infer that the local volumetric birth rate of 19dge-like ultra-stripped SNe is in the range of 1400–8200 Gpc − 3 yr − 1 (i.e., 2%–12% of core-collapse supernova rate). This can be compared to the observed coalescence rate of compact neutron star binaries that are not formed by dynamical capture.
Source: The Astrophysical Journal
Authors: Yuhan Yao, Kishalay De, Mansi M. Kasliwal, Anna Y. Q. Ho, Steve Schulze, Zhihui Li, S. R. Kulkarni, Andrew Fruchter, David Rubin, Daniel A. Perley, Jim Fuller, Anthony L. Piro, C. Fremling, Eric C. Bellm, Rick Burruss, Dmitry A. Duev, Michael Feeney, Avishay Gal-Yam, V. Zach Golkhou, Matthew J. Graham, George Helou, Thomas Kupfer, Russ R. Laher, Frank J. Masci, Adam A. Miller, Ben Rusholme, David L. Shupe, Roger Smith, Jesper Sollerman, Maayane T. Soumagnac, Jeffry Zolkower
Institutions: California Institute of Technology, Weizmann Institute of Science, Space Telescope Science Institute, University of Hawaiʻi at Mānoa, University of Hawaii System, Liverpool John Moores University, Carnegie Institution for Science, Carnegie Observatories, University of Washington, Infrared Processing and Analysis Center, University of California, Santa Barbara, Kavli Institute for Theoretical Physics, Northwestern University, Adler Planetarium, Stockholm University, AlbaNova, Lawrence Berkeley National Laboratory
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W3032465440