The High-frequency Radio Emission of the Galactic Center Magnetar SGR J1745–29 during a Transitional Period

The origin of the high-frequency radio emission detected from several magnetars is poorly understood. In this paper, we report the similar to 40 GHz properties of SGR J1745-29 measured using Jansky Very Large Array (JVLA) and Robert C. Byrd Green Bank Telescope (GBT) observations between 2013 October 26 and 2014 May 31. Our analysis of a Q-band (45GHz) GBT observation on 2014 April 10 resulted in the earliest detection of pulsed radio emission at high frequencies (greater than or similar to 20 GHz); we found that the average pulse has a singly peaked profile with width similar to 75 ms (similar to 2% of the 3.764 s pulse period) and an average pulsed flux density of similar to 100 mJy. We also detected very bright, short (