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Active galactic nuclei (AGNs) show episodic activity, evident in galaxiesthat exhibit restarted radio jets. These restarted jets can interact with theirenvironment, leaving signatures on the radio spectral energy distribution.Tracing these signatures requires resolved spectral index measurements over abroad frequency range including low frequencies. We present such a study forthe radio galaxy 3C 293. Using the International LOFAR telescope (ILT) weprobed spatial scales as fine as ~0.2" at 144 MHz, and to constrain thespectrum we combined these data with Multi-Element Radio Linked InterferometerNetwork (MERLIN) and Very Large Array (VLA) archival data. In the inner lobes(~2 kpc), we detect the presence of a spectral turnover that peaks at ~225 MHzand is most likely caused by free-free absorption from the rich surroundingmedium. We confirm that these inner lobes are part of a jet-dominated youngradio source (spectral age $\lesssim$0.17 Myr), which is strongly interactingwith the rich interstellar medium (ISM) of the host galaxy. The outer lobes(~100 kpc) have a spectral index of $\alpha$~0.6-0.8 from 144-4850 MHz with aremarkably uniform spatial distribution and only mild spectral curvature($\Delta\alpha\lesssim$ 0.2). We propose that intermittent fuelling and jetflow disruptions are powering the mechanisms that keep the spectral index inthe outer lobes from steepening and maintain the spatial uniformity of thespectral index. Overall, it appears that 3C 293 has gone through multiple (twoto three) epochs of activity. This study adds 3C 293 to the new sub-group ofrestarted galaxies with short interruption time periods. This is the first timea spatially resolved study simultaneously studies a young source as well as theolder outer lobes at such low frequencies. This illustrates the potential ofthe ILT to expand such studies to a larger sample of radio galaxies.

Unmasking the history of 3C 293 with LOFAR sub-arcsecond imaging