Using the newly discovered X-ra- IR Type-I bursts to probe jet-disk interaction

During AO 18 our team discovered the presence of two IR bursts laggingthermonuclear TypeI Xray bursts\\: this allowed us to put the first constraintson the orbital period of the source 4U 172834. Moreover, the profiles of thenewly discovered IR bursts showed intriguing .dips. just after the onset of theXray bursts. The aim of this proposal is to use the novel method of XrayIRburst lag to measure the orbital period of 4U 172834 and two other sources, andto quantify the presence of .dips. in their IR reverberation, signatures thatwould indicate burstinduced changes in the geometry of the accretion flow. Wetherefore ask to perform 4 (total 56ks) XMM pointings to be matched by 4 (total14h) HAWKI@VLT observations of 4U 172834, 4U 170544 and 4U 163653. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]