RT_CRU
The goal of the proposed XRISM observation is to show that high-resolution X-ray spectroscopy can directly reveal the mass of an accreting white dwarf (WD). By measuring the centroids of Fe Ka and Kb; fluorescent lines reflected from the WD, we will determine the gravitational redshift at the WD surface and hence the WD mass in RT Cru, the most hard-X-ray luminous symbiotic binary star. The mass of this WD is thought to be above the likely upper limit for its birth mass. Confirmation of this situation would imply that the mass is almost certainly increasing, establishing a subset of symbiotic stars as viable progenitors for some Type Ia supernovae. Because this project uses emission lines in the 6-7 keV range, it is minimally impacted by the Gate Valve remaining in the closed configuration
obsid = 201090010 / Unique Observation/Sequence Number
object = RT_CRU / Object name
pi_name = SOKOLOSKI JENNIFER / Proposal Principal Investigator Name
ra = 188.723895663622 / Right Ascension (Pointing Position) (deg)
dec = -64.5657614409595 / Declination (Pointing Position) (deg)
roll_angle = 261.577136688067 / Roll Angle (deg)
start_time = 2025-06-09T12:00:04 / Start Time of the Observation
stop_time = 2025-06-13T20:07:04 / Stop Time of the Observation
exposure = 177705.73638 / Effective Total Observation Exposure (s)
public_date= 2026-06-19 / Public Date