We present the results of VLA , ATCA , and Swift XRT observations of the 2015 outburst of the transient neutron star X-ray binary ( NSXB ) , EXO 1745 - 248 , located in the globular cluster Terzan 5 .
Combining ( near- ) simultaneous radio and X-ray measurements we measure a correlation between the radio and X-ray luminosities of L _ { R } \propto L _ { X } ^ { \beta } with \beta = 1.68 ^ { +0.10 } _ { -0.09 } , linking the accretion flow ( probed by X-ray luminosity ) and the compact jet ( probed by radio luminosity ) .
While such a relationship has been studied in multiple black hole X-ray binaries ( BHXBs ) , this work marks only the third NSXB with such a measurement .
Constraints on this relationship in NSXBs are strongly needed , as comparing this correlation between different classes of XB systems is key in understanding the properties that affect the jet production process in accreting objects .
Our best fit disc-jet coupling index for EXO 1745 - 248 is consistent with the measured correlation in NSXB 4U 1728 - 34 ( \beta = 1.5 \pm 0.2 ) but inconsistent with the correlation we fit using the most recent measurements from the literature of NSXB Aql X-1 ( \beta = 0.76 ^ { +0.14 } _ { -0.15 } ) .
While a similar disc-jet coupling index appears to hold across multiple BHXBs in the hard accretion state , this does not appear to be the case with the three NSXBs measured so far .
Additionally , the normalization of the EXO 1745 - 248 correlation is lower than the other two NSXBs , making it one of the most radio faint XBs ever detected in the hard state .
We also report the detection of a type-I X-ray burst during this outburst , where the decay timescale is consistent with hydrogen burning .