IGR_J16318-4848
We propose to observe IGR J16318-4848, the most obscured X-ray source in our Galaxy, to study X-ray reflection in the Compton-thick regime. In this high-mass X-ray binary, XRISM will reveal detailed reflection features such as strong Fe Ka, Fe Kb, and Ni Ka lines with resolved line shapes, a structured Fe K-edge, and one of the best-resolved Compton shoulders, shedding light on the obscuring medium. Moreover, XRISM could confirm the tentative Ni overabundance and the unexpectedly low velocity broadening reported for this source, which would imply that the X-ray reprocessor is related to supernova ejecta rather than a dense stellar wind. More generally, this source will serve as a unique laboratory to study X-ray processes, and benchmark obscuration models for AGNs and XRBs.
obsid = 202099010 / Unique Observation/Sequence Number
object = IGR_J16318-4848 / Object name
pi_name = MEULEN BERT / Proposal Principal Investigator Name
ra = 247.952147590666 / Right Ascension (Pointing Position) (deg)
dec = -48.8173661071631 / Declination (Pointing Position) (deg)
roll_angle = 86.4083081552888 / Roll Angle (deg)
start_time = 2026-02-04T00:14:04 / Start Time of the Observation
stop_time = 2026-02-06T04:31:04 / Stop Time of the Observation
exposure = 143469.76687 / Effective Total Observation Exposure (s)
public_date= 2099-12-31 / Public Date