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 our radio observational campaign on GRB 100418a,for which we used the Australia Telescope Compact Array (ATCA), Very LargeArray (VLA) and the Very Long Baseline Array (VLBA). GRB 100418a was a peculiarGRB with unusual X-ray and optical afterglow profiles featuring a plateau phasewith a very shallow rise. This observed plateau phase was believed to be due toa continued energy injection mechanism which powered the forward shock, givingrise to an unusual and long-lasting afterglow. The radio afterglow of GRB100418a was detectable several weeks after the prompt emission. We conductedlong-term monitoring observations of the afterglow and attempted to test theenergy injection model advocating that the continuous energy injection is dueto shells of material moving at a wide range of Lorentz factors. We obtained anupper limit of $\gamma$ $<$ 7 for the expansion rate of the GRB 100418a radioafterglow, indicating that the range-of-Lorentz factor model could only beapplicable for relatively slow moving ejecta. A preferred explanation could bethat continued activity of the central engine may have powered the long-lastingafterglow.

Radio observations of GRB 100418a: Test of an energy injection model explaining long-lasting GRB afterglows