Cas_A_SW
We propose 150 ks XRISM observation of the southwestern region of supernova remnant (SNR) Cassiopeia A (Cas A). Our goals are to observe an enhanced forbidden-to-resonance (f/r) ratio in a region where the radio observation suggested an interaction between SNR and molecular cloud (SNR/MC interaction) and to determine the f/r ratio accurately in a region where an anomalous value was observed in the PV phase. Based on the XRISM/Resolve spectra in PV observation, we have detected a narrow spectral component and discovered an enhanced f/r ratio in the western rim. These features are expected consequences of the ejecta/MC interaction. The proposed observation provides an independent test of this scenario, as the planned region includes the area of suspected SNR/MC interaction.
obsid = 202073010 / Unique Observation/Sequence Number
object = Cas_A_SW / Object name
pi_name = SONODA HARUTO / Proposal Principal Investigator Name
ra = 350.835228626968 / Right Ascension (Pointing Position) (deg)
dec = 58.7966428429852 / Declination (Pointing Position) (deg)
roll_angle = 78.5056293271329 / Roll Angle (deg)
start_time = 2026-05-28T06:08:04 / Start Time of the Observation
stop_time = 2026-06-01T02:20:04 / Stop Time of the Observation
exposure = 242424.0173 / Effective Total Observation Exposure (s)
public_date= 2099-12-31 / Public Date