CYG_X-3
Cyg X-3 is a high-mass X-ray binary composed of a compact object and a Wolf-Rayet star, notable for wind-fed mass accretion. The PV observation of Cyg X-3 in the ultrasoft state provided us data of astonishing quality, raising strong expectations for XRISM observations in the hard state, whose X-ray spectrum is characterized by a hard continuum with a prominent Fe K alpha line at 6.4 keV. We propose an 80 ks observation of the hard state to (1) to probe the geometry and kinematics of matter around the accretion flow using the Fe K alpha line and (2) to estimate the mass transfer rate using various absorption lines. A comparative study of the mass transfer rate in the two different states is expected to provide insight into the yet unresolved mechanism behind state transitions.
obsid = 202085010 / Unique Observation/Sequence Number
object = CYG_X-3 / Object name
pi_name = MIURA DAIKI / Proposal Principal Investigator Name
ra = 308.107699404047 / Right Ascension (Pointing Position) (deg)
dec = 40.9577810487284 / Declination (Pointing Position) (deg)
roll_angle = 247.25660282947 / Roll Angle (deg)
start_time = 2025-11-12T07:11:04 / Start Time of the Observation
stop_time = 2025-11-14T14:08:04 / Stop Time of the Observation
exposure = 97891.908952 / Effective Total Observation Exposure (s)
public_date= 2026-11-27 / Public Date