English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We present the results of ALMA band 3 observations of a nearby type Icsupernova (SN) 2020oi. Under the standard assumptions on the SN-circumstellarmedium (CSM) interaction and the synchrotron emission, the data indicate thatthe CSM structure deviates from a smooth distribution expected from thesteady-state mass loss in the very vicinity of the SN (~10^{15} cm), which isthen connected to the outer smooth distribution (~10^{16} cm). This structureis further confirmed through the light curve modeling of the whole radio dataset as combined with data at lower frequency previously reported. Being anexplosion of a bare carbon-oxygen (C+O) star having a fast wind, we can tracethe mass-loss history of the progenitor of SN 2020oi in the final year. Theinferred non-smooth CSM distribution corresponds to fluctuations on thesub-year time scale in the mass-loss history toward the SN explosion. Ourfinding suggests that the pre-SN activity is likely driven by the acceleratedchange in the nuclear burning stage in the last moments just before the massivestar's demise. The structure of the CSM derived in this study is beyond theapplicability of the other methods at optical wavelengths, highlighting animportance and uniqueness of quick follow-up observations of SNe by ALMA andother radio facilities.

The final months of massive star evolution from the circumstellar environment around SN Ic 2020oi