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 Tools annual

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 monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

Spectral variability of radio sources encodes information about theconditions of intervening media, source structure, and emission processes. Withnew low-frequency radio interferometers observing over wide fractionalbandwidths, studies of spectral variability for a large population ofextragalactic radio sources are now possible. Using two epochs of observationsfrom the GaLactic and Extragalactic All-sky Murchison Widefield Array (GLEAM)survey that were taken one year apart, we search for spectral variabilityacross 100--230 MHz for 21,558 sources. We present methodologies for detectingvariability in the spectrum between epochs and for classifying the type ofvariability: either as a change in spectral shape or as a uniform change influx density across the bandwidth. We identify 323 sources with significantspectral variability over a year-long timescale. Of the 323 variable sources,we classify 51 of these as showing a significant change in spectral shape.Variability is more prevalent in peaked-spectrum sources, analogous togigahertz-peaked spectrum and compact steep-spectrum sources, compared totypical radio galaxies. We discuss the viability of several potentialexplanations of the observed spectral variability, such as interstellarscintillation and jet evolution. Our results suggest that the radio sky in themegahertz regime is more dynamic than previously suggested.

Spectral Variability of Radio Sources at Low Frequencies