2025/06/09 by Hughes, Andrew K., Carotenuto, Francesco, Russell, Thomas D. +39 · 1 citation
#FOS: Physical sciences #High Energy Astrophysical Phenomena (astro-ph.HE)
paper · doi:10.48550/arxiv.2506.07798
This work presents comprehensive multi-frequency radio monitoring of the black hole low-mass X-ray binary Swift J1727.8-1613, which underwent its first recorded outburst after its discovery in August 2023. Through a considerable community effort, we have coalesced the data from multiple, distinct observing programs; the light curves include ∼ 10 months and 197 epochs of monitoring from 7 radio facilities with observing frequencies ranging from (approximately) 0.3-230GHz. The primary purpose of this work is to provide the broader astronomical community with these light curves to assist with the interpretation of other observing campaigns, particularly non-radio observing frequencies. We discuss the phenomenological evolution of the source, which included: (i) multiple radio flares consistent with the launching of discrete jet ejections, the brightest of which reached ∼ 1 Jy; (ii) temporally evolving radio spectral indices (α), reaching values steeper than expected for optically-thin synchrotron emission (α< -1) and emission with significant radiative cooling (α< -1.5). We have published a digital copy of the data and intend for this work to set a precedent for the community to continue releasing comprehensive radio light curves of future low-mass X-ray binary outbursts.