News

We have currently triggered on Swift J1727.8-1613.

Triggering Guidelines

We aim to observe six black hole X-ray binaries throughout their outbursts with the JCMT between February 2020 - January 2023 (1 per semester, based on current outburst rates). As we wish to sample timing and polarimetric property evolution throughout outburst, we define two types of outburst monitoring campaigns, long (16 x 4-hour epochs) and short (8 x 4-hour epochs), splitting our six triggers into 2 long campaigns and 4 short campaigns.

Following the positive identification of an out-bursting BHXB (from X-ray all-sky monitors MAXI/Swift BAT or early identification through optical monitoring), the decision to trigger will be made using our trigger decision tree (see Figure 1). This decision tree is based on the following criteria: our trigger threshold (as measured with transient monitoring radio facilities such as AMI/ATCA/VLA), current accretion state (as determined from X-ray spectral and timing observations), and how rapidly the radio/X-ray emission from the target is evolving (e.g., how rapidly is the flux rising, how rapidly are the X-ray spectral/timing properties changing).

Fig.1 - Trigger Decision Tree.