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

In this Letter we discuss the recently discovered radio transient in the nuclear region of M82. It has been suggested that this source is an X‐ray binary, which, given the radio flux density, would require an X‐ray luminosity,  L  X  ∼ 6 × 10 42  erg s −1  if it were a stellar mass black hole that followed established empirical relations for X‐ray binaries. The source is not detected in the analysis of the X‐ray archival data. Using a 99 per cent confidence level upper limit we find that  L  X ≤ 1.8 × 10 37  and 1.5 × 10 37  erg s −1 , using power law and disc blackbody models, respectively. The source is thus unlikely to be a traditional microquasar, but could be a system similar to SS 433, a Galactic microquasar with a high ratio of radio to X‐ray luminosity.

The unusual radio transient in M82: an SS 433 analogue?