A Radio Frequency Study of the Accreting Millisecond X-ray Pulsar, IGR J16597-3704, in the Globular Cluster NGC 6256

Abstract

We present Karl G. Jansky Very Large Array radio frequency observations of the new accreting millisecond X-ray pulsar (AMXP), IGR J16597-3704, located in the globular cluster NGC 6256. With these data, we detect a radio counterpart to IGR J16597-3704, and determine an improved source position. Pairing our radio observations with quasi-simultaneous Swift/XRT X-ray observations, we place IGR J16597-3704 on the radio-X-ray luminosity plane, where we find that IGR J16597-3704 is one of the more radio-quiet neutron star low-mass X-ray binaries known to date. We discuss the mechanisms that may govern radio luminosity (and in turn jet production and evolution) in AMXPs. Furthermore, we use our derived radio position to search for a counterpart in archival Hubble Space Telescope and Chandra X-ray Observatory data, and estimate an upper limit on the X-ray luminosity of IGR J16597-3704 during quiescence.