Free Access

Fig. 9.


Spectral index maps of the Toothbrush, at resolution, showing remarkably similar spectral index patterns up to 6 GHz. The variations in the spectral index at the outer edge along the relic are clearly visible, reflecting inhomogeneities in the injection index. Top: low-frequency spectral index maps between 150 and 1500 MHz. Bottom: high-frequency spectral index maps between 1.5 and 6 GHz. The color bar shows spectral index α from −2.5 to 0.5. Bottom: all maps, contour levels are drawn at [1, 2, 4, 8, …]×4σrms and are from the 150 MHz LOFAR image. These maps were created using the IM2, IM6, IM11, IM15, and IM19 (see Table 2 for image properties).

Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.

Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.

Initial download of the metrics may take a while.