Evidence of mutually exclusive outflow forms from a black hole X-ray binary

TL;DR

This study reveals that in a black hole X-ray binary, disk winds and jets are mutually exclusive during outbursts, indicating a competitive relationship influenced by how accretion energy is distributed.

Contribution

It provides the first observational evidence of anti-correlated outflow modes in a black hole X-ray binary during outbursts.

Findings

Detected anti-correlation between winds and jets during outbursts.

Observed exclusivity of outflow types even at similar accretion luminosities.

Suggests competition between outflow channels based on energy partitioning.

Abstract

Accretion onto black holes often leads to the launch of outflows that significantly influence their surrounding environments. The two primary forms of these outflows are X-ray disk winds-hot, ionized gases ejected from the accretion disk-and relativistic jets, which are collimated streams of particles often expelled along the rotational axis of the black hole. While previous studies have revealed a general association between spectral states and different types of outflows, the physical mechanisms governing wind and jet formation remain debated. Here, using coordinated NICER and MeerKAT observations of the recurrent black hole X-ray binary 4U 1630-472, we identify a clear anti-correlation between X-ray disk winds and jets: during three recent outbursts, only one type of outflow is detected at a time. Notably, this apparent exclusivity occurs even as the overall accretion luminosity remains within the range expected for a standard thin disk, characteristic of the canonical soft state. These results suggest a competition between outflow channels that may depend on how the accretion energy is partitioned between the disk and the corona. Our findings provide new observational constraints on jet and wind formation in X-ray binaries and offer a fresh perspective on the interplay between different modes of accretion-driven feedback.