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

• Published in: Monthly notices of the Royal Astronomical Society 2021-06, Vol.504 (1), p.444-468
• Main Authors: Carotenuto, F, Corbel, S, Tremou, E, Russell, T D, Tzioumis, A, Fender, R P, Woudt, P A, Motta, S E, Miller-Jones, J C A, Chauhan, J, Tetarenko, A J, Sivakoff, G R, Heywood, I, Horesh, A, van der Horst, A J, Koerding, E, Mooley, K P
• Format: Article
• Language: English
• ISSN: 0035-8711; 1365-2966
• DOI: 10.1093/mnras/stab864

ABSTRACT 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.