GX339-4
The evolution of accretion disks as a function of the Eddington-scaled mass accretion rate is at the heart of black hole fueling and ejection. A central prediction is that the inner disk should be truncated below a threshold in M-dot because cooling becomes inefficient. This is the basis for radiatively- inefficient accretion flow models (RIAFs), and may the key to jet production. Yet, even in stellar-mass black holes, observations offer little clear evidence of disk truncation at accessible fluxes. In the recurrent transient GX 339-4, however, there is enough continuum and Fe K-a line flux at an Eddington fraction of 0.001 to obtain definitive, positive evidence of disk truncation in a 30 ks XRISM exposure. We request a TOO observation of GX 339-4 in Cycle 2.
obsid = 202000010 / Unique Observation/Sequence Number
object = GX339-4 / Object name
pi_name = MILLER JON / Proposal Principal Investigator Name
ra = 255.705345043519 / Right Ascension (Pointing Position) (deg)
dec = -48.7908408353902 / Declination (Pointing Position) (deg)
roll_angle = 81.1542404020929 / Roll Angle (deg)
start_time = 2026-02-06T04:31:04 / Start Time of the Observation
stop_time = 2026-02-07T00:20:04 / Stop Time of the Observation
exposure = 41261.698944 / Effective Total Observation Exposure (s)
public_date= 2099-12-31 / Public Date