Magnetar XTEJ1810-197 follow-up 300-1450MHz GMRT obs.

We report the results from a 2.5yr monitoring campaign with the upgraded Giant Metrewave Radio Telescope, carried out over the frequency range of 300-1450MHz. Our observations show intriguing time variability in the average profile width, flux density, spectral index, and broadband spectral shape.

While the average profile width appears to gradually decrease at later epochs, the flux density shows multiple episodes of radio rebrightening over the course of our monitoring. Our systematic monitoring observations reveal that the radio spectrum has steepened over time, resulting in evolution from a magnetar-like spectrum to a more pulsar-like spectrum. A more detailed analysis reveals that the radio spectrum has a turnover, and that this turnover shifts toward lower frequencies with time.