We present results from observations of the Galactic Center magnetar , PSR J1745–2900 , at 2.3 and 8.4 GHz with the NASA Deep Space Network 70 m antenna , DSS-43 .
We study the magnetar ’ s radio profile shape , flux density , radio spectrum , and single pulse behavior over a \sim 1 year period between MJDs 57233 and 57621 .
In particular , the magnetar exhibits a significantly negative average spectral index of \langle \alpha \rangle = –1.86 \pm 0.02 when the 8.4 GHz profile is single-peaked , which flattens considerably when the profile is double-peaked .
We have carried out an analysis of single pulses at 8.4 GHz on MJD 57479 and find that giant pulses and pulses with multiple emission components are emitted during a significant number of rotations .
The resulting single pulse flux density distribution is incompatible with a log-normal distribution .
The typical pulse width of the components is \sim 1.8 ms , and the prevailing delay time between successive components is \sim 7.7 ms .
Many of the single pulse emission components show significant frequency structure over bandwidths of \sim 100 MHz , which we believe is the first observation of such behavior from a radio magnetar .
We report a characteristic single pulse broadening timescale of \langle \tau _ { d } \rangle = 6.9 \pm 0.2 ms at 8.4 GHz .
We find that the pulse broadening is highly variable between emission components and can not be explained by a thin scattering screen at distances \gtrsim 1 kpc .
We discuss possible intrinsic and extrinsic mechanisms for the magnetar ’ s emission and compare our results to other magnetars , high magnetic field pulsars , and fast radio bursts .