«A Microquasar Odyssey: Unveiling the Complexities»

First sub-second Infrared/X-ray observations of low inclination black hole X-ray transient 4U 1543-475

Not scheduled

15m

Palazzo Municipale - Sala delle Capriate (Cefalù (Palermo))

Talk Talk Timing properties (Observations, modelling)

Speaker

Ms Sian Akua Woahene-Demehin (University of Southampton)

Description

In recent years, fast optical-infrared (O-IR) variability of LMXBs has opened a new window in the study of the jet and accretion flow properties. All objects observed thus far are known to have an intermediate-high inclination, biasing our interpretations and hampering the possibility of adequately testing models. Here, I present the first sub-second multiwavelength analysis of low inclination black hole X-ray transient 4U 1543-475 (i<30 deg.). Observations were taken during its 2022 outburst using sub-second observations from HAWK-I@VLT (IR) and NICER (X-ray). Similarly to higher inclination objects, cross-correlation analysis shows a strong correlation between the IR and X-ray bands with IR lagging the X-rays by ~100 ms. More interestingly, an IR QPO is detected at 0.07 Hz with an X-ray counterpart at twice the IR frequency (0.14 Hz), indicating a possible harmonic relation. These results provide the first constraints on jet timing signatures at low viewing angles, representing a key dataset for our understanding of these collimated outflows.