The black hole transient MAXI J1348-630: evolution of the compact and transient jets during its 2019/2020 outburst

Journal article

We present the radio and X-ray monitoring campaign of the 2019/2020 outburst of MAXI J1348-630, a new black hole X-ray binary (BH XRB) discovered in 2019 January. We observed MAXI J1348-630 for ∼14 months in the radio band with MeerKAT and the Australia Telescope Compact Array, and in the X-rays with MAXI and Swift/XRT. Throughout the outburst, we detected and tracked the evolution of compact and transient jets. Following the main outburst, the system underwent at least four hard-state-only re-flares, during which compact jets were again detected. For the major outburst, we observed the rise, quenching and reactivation of compact jets, as well as two single-sided discrete ejecta travelling away from the BH, launched ∼2 months apart. These ejecta displayed the highest proper motion (≳100 mas d-1) ever measured for an accreting BH binary. From the jet motion, we constrain the ejecta inclination and speed to be ≤46° and ≥0.69 c, and the opening angle and transverse expansion speed of the first component to be ≤6° and ≤0.05 c. We also infer that the first ejection happened at the hard-to-soft state transition, before a strong radio flare, while the second ejection was launched during a short excursion from the soft to the intermediate state. After travelling with constant speed, the first component underwent a strong deceleration, which was covered with unprecedented detail and suggested that MAXI J1348-630 could be located inside a low-density cavity in the interstellar medium, as already proposed for XTE J1550-564 and H1743-322.

Authors: Carotenuto, F; Corbel, S; Tremou, E; Russell, TD; Tzioumis, A

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Oxford University Press
• Journal: Monthly Notices of the Royal Astronomical Society
• Volume: 504
• Issue: 1
• Pages: 444-468
• Publication date: 2021-03-26
• Acceptance date: 2021-03-22
• DOI: 10.1093/mnras/stab864
• EISSN: 1365-2966
• ISSN: 0035-8711
• Language: English
• Keywords: X-rays: binaries; X-rays: individual: MAXI J1348-630; FFR; radio continuum: stars; accretion; black hole physics; accretion discs; ISM: jets and outflows