Search for radio pulsations in AMXPs

We have carried out a search for radio pulsed emission from the Accreting Millisecond X‐ray pulsars (AMXPs) XTE J0929‐314, XTE J1751‐305 and XTE J1814‐338 at 6.5 and 8.5 GHz, observed during their X‐Ray quiescent phase. The detection of radio signals, in the quiescent phase of this kind of transient systems, would give a ultimate proof of the recycling model, unambiguously establishing that the AMXPs are the progenitors of the Radio millisecond pulsars. For the first source we can conclude that no radio pulsation is present in the analyzed data down to a limit of 68 μJy at 6.4 GHz and 26 μJy at 8.5 GHz. We discuss several mechanisms that could prevent the detection and suggest that the free‐free absorption cannot be responsible for the lack of a detection, given the relatively high used radio frequencies, while the beaming factor and the intrinsic low luminosity are viable explanations for the non detection of radio pulsation. For the other two sources the work is now in progress.