An environmental analysis of the fast transient AT2018cow and implications for its progenitor and late-time brightness
Published: 6 January 2023
Monthly Notices of the Royal Astronomical Society , Volume 519, pp 3785-3797; https://doi.org/10.1093/mnras/stac3773
Abstract: The nature of the newly discovered fast blue optical transients (FBOTs) is still puzzling astronomers. In this paper, we carry out a comprehensive analysis of the molecular gas, ionized gas, and stellar populations in the environment of the nearby FBOT AT2018cow based on ALMA, VLT/MUSE, and HST/WFC3 observations. A prominent molecular concentration of 6 (± 1) × 106 M⊙ is found in the vicinity of AT2018cow, which has given rise to two active star-forming complexes with ages of 4 ± 1 and ≲2.5 Myr, respectively. Each star-forming complex has a stellar mass of 3 × 105 M⊙, and has photoionized a giant H ii region with Hα luminosity even comparable to that of the 30 Dor mini-starburst region. AT2018cow is spatially coincident with one of the star-forming complexes; however, it is most likely to reside in its foreground since it has a much smaller extinction than the complex. Its progenitor could have been formed in a different star-forming event, and the non-detection of the associated stellar population constrains the progenitor’s age to be ≳10 Myr and initial mass to be ≲20 M⊙. We further find the late-time brightness of AT2018cow is unlikely to be a stellar object. Its brightness has slightly declined from 2 to 4 yr after explosion and is most likely to originate from AT2018cow itself due to some powering mechanism still working at such late times.
Keywords: supernovae: general / supernovae: individual: 2018cow
Scifeed alert for new publicationsNever miss any articles matching your research from any publisher
- Get alerts for new papers matching your research
- Find out the new papers from selected authors
- Updated daily for 49'000+ journals and 6000+ publishers
- Define your Scifeed now
Click here to see the statistics on "Monthly Notices of the Royal Astronomical Society" .