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

Maser lines of OH, H2 O, and SiO are commonly observed in O-rich AGB stars,but their presence after the end of the Asymptotic Giant Branch (AGB) phase islinked to non-spherical mass-loss processes. IRAS 15452-5459 is a post-AGB starwith an hourglass nebula whose maser lines are quite peculiar. We observed allof the three maser species with the Australia Telescope Compact Array withangular resolutions of 6'' , 0.6'' , 0.3'' , and 1.7'' at 18 cm, 13 mm, 7 mm,and 3 mm, respectively. While double peaks are routinely seen in OH and watermasers and interpreted as due to expanding envelopes, only very few sourcesdisplay SiO lines with a similar spectral profile. Our observations confirm thedetection of the double peak of SiO at 86 GHz; the same spectral shape is seenin the lower-J maser at 43 GHz. A double peak is also detected in the waterline, which covers the same velocity range as the SiO masers. Thermally excitedlines of SiO are detected at 7 and 3 mm and span the same velocity range as themaser lines of this species. Although observations at higher angular resolutionare desirable to further investigate the spatial distributions of the maserspots, the current data allow us to conclude that the SiO masers aredistributed in an hourglass shape and are likely due to the sputtering of dustgrains caused by shock propagation. The complex OH profile would instead be dueto emission from the fast outflow and an orthogonal structure.

Probing the fast outflow in IRAS 15452-5459 with ATCA observations of OH, H2O, and SiO masers