Accretion disc winds are thought to play a significant role in shaping the outbursts of X-ray binaries (XRBs) by extracting mass and momentum from these systems. The study of cold, low-ionisation winds, detected through hydrogen and helium lines at optical and infrared (OIR) wavelengths, has recently provided substantial insights into their properties. The analysis of the optically thick wind...
Transitional millisecond pulsars (tMSP) represent a dynamic category of celestial sources that establish a crucial connection between low-mass X-ray binaries and millisecond radio pulsars. These systems exhibit transitions from rotation-powered to accretion-powered states and vice versa, highlighting the tight evolutionary link expected by the so-called recycling scenario. In their active...
Accreting stellar-mass black holes in X-ray binaries offer a unique opportunity to study black hole accretion in relatively clean environments and on human-accessible timescales—much shorter than those typical of AGN and quasars. Over the past few decades, the coupling between accretion and ejection processes in these systems has been extensively investigated, primarily through X-ray and radio...
In this talk, I will present a study of the optical counterpart of the black hole X-ray binary MAXI J1820+070 during its main 2018 outburst and subsequent three reflares. The goal is to track the evolution of outflows across different spectral states and investigate the origin of minute-timescale optical variability. We collected high-cadence multi-filter optical light curves using the Las...
The X-ray transient MAXI J1810-222 was discovered in 2018 and has been active ever since. A deep, ongoing, multiwavelength monitoring campaign suggests a black hole accretor, although the unusual outburst behaviour. Through a NICER monitoring we detected a strong spectral absorption feature around 1 keV which can be described with a photoionised absorber. A deep scan of the parameters space...
Powerful ionized winds are often observed during episodic outbursts in black hole X-ray binaries (aka. microquasars). Focused on X-ray band, the observed highly ionized absorbers of multiple ions are thought to be launched and accelerated from an accretion disk by some means. The current disk wind theory suggests multiple driving mechanisms with distinct characteristics, which may well...
