The delicate interplay between accretion, ejection and magnetism in neutron stars X-ray binaries

Authors
Dr.
Alessio Marino
Date and time
12 Jun 2025 - 10:30 Europe/London
Address

Aula

Talk language
English
Slides language
English
Serie number
1
Description

Matter ejection, in the form of either winds or jets, is ubiquitous in accreting X-ray binaries. Although it is clear that accretion and ejection are profoundly intertwined in these types of systems, the origin and the details of such an interconnection are yet to be unraveled. This is particularly true for systems where a low-magnetized neutron star (NS) accretes matter from a low-mass companion star (NS low-mass X-ray binaries, LMXBs). Indeed, unlike the case of accreting black holes, in NS LMXBs the already delicate interplay between accretion and ejection may be further complicated by the presence of, e.g., the NS magnetic field, the boundary layer and the emission from the NS surface. For instance, jets in NS LMXBs have been claimed to be more collimated than in BH LMXBs, their occurrence sometimes seems to be unrelated to the spectral state and their observed radio luminosity show a rather scattered distribution. X-ray winds on the other hand have been often detected in states where they were not expected, in particular in a class of NS LMXBs, the Accreting Millisecond X-ray Pulsars (AMXPs), where the channeling of the accretion flow along the magnetic field lines makes these systems visible as rapidly spinning X-ray pulsars. Finally, AMXPs typically drive more powerful jets than other (non-pulsating) NS LMXBs and their rapid orbital expansion can be explained by strong mass outflows. In this talk, I will review the emerging pattern of peculiar outflows in NS LMXBs, the possible implications for jet and wind-launching mechanisms in these systems and the key role that future multi-band observing campaigns will play in clarifying its physical origin.
Format