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 have used the Australia Telescope Compact Array (ATCA) to make newobservations of the 36.2-GHz ($4_{-1}\rightarrow3_0$E) methanol transitiontoward NGC 4945 and NGC 253. These observations have revealed the presence ofnew maser components toward these galaxies, and have provided the first clearevidence for variability in extragalactic class~I methanol masers. Alongsidethe new observations of NGC 4945 and NGC 253, we present the results of recent36.2-GHz methanol maser searches toward 12 galaxies, placing upper limits onthe emission from the 36.2-GHz class~I transition and the 37.7-GHz($7_{2}\rightarrow8_1$E) class~II maser line toward these sources. Flux densityvalues for the 7-mm continuum emission toward these sources are also reportedwhere applicable. A re-analysis of the published 36.2-GHz methanol observationsof Arp 220 undertaken as part of the search revealed some issues with previousimaging procedures. The re-analysis, combined with non-detections inindependent follow-up observations suggest that there is no 36.2-GHz methanolemission toward Arp 220 stronger than 3.5 mJy in a 10 km s$^{-1}$ channel(5$\sigma$ upper limit).

Variability in extragalactic class I methanol masers: New maser components toward NGC4945 and NGC253